diff options
28 files changed, 1021 insertions, 753 deletions
diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index c3e634ebd908..87bd0e3271b0 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -6598,6 +6598,12 @@ unknown_nmi_panic [X86] Cause panic on unknown NMI. + unwind_debug [X86-64] + Enable unwinder debug output. This can be + useful for debugging certain unwinder error + conditions, including corrupt stacks and + bad/missing unwinder metadata. + usbcore.authorized_default= [USB] Default USB device authorization: (default -1 = authorized except for wireless USB, diff --git a/arch/powerpc/kernel/smp.c b/arch/powerpc/kernel/smp.c index e8965f18686f..e95660e69414 100644 --- a/arch/powerpc/kernel/smp.c +++ b/arch/powerpc/kernel/smp.c @@ -1605,6 +1605,7 @@ static void add_cpu_to_masks(int cpu) } /* Activate a secondary processor. */ +__no_stack_protector void start_secondary(void *unused) { unsigned int cpu = raw_smp_processor_id(); diff --git a/arch/x86/entry/thunk_64.S b/arch/x86/entry/thunk_64.S index 5e37f41e5f14..27b5da2111ac 100644 --- a/arch/x86/entry/thunk_64.S +++ b/arch/x86/entry/thunk_64.S @@ -26,17 +26,7 @@ SYM_FUNC_START(\name) pushq %r11 call \func - jmp __thunk_restore -SYM_FUNC_END(\name) - _ASM_NOKPROBE(\name) - .endm - - THUNK preempt_schedule_thunk, preempt_schedule - THUNK preempt_schedule_notrace_thunk, preempt_schedule_notrace - EXPORT_SYMBOL(preempt_schedule_thunk) - EXPORT_SYMBOL(preempt_schedule_notrace_thunk) -SYM_CODE_START_LOCAL(__thunk_restore) popq %r11 popq %r10 popq %r9 @@ -48,5 +38,11 @@ SYM_CODE_START_LOCAL(__thunk_restore) popq %rdi popq %rbp RET - _ASM_NOKPROBE(__thunk_restore) -SYM_CODE_END(__thunk_restore) +SYM_FUNC_END(\name) + _ASM_NOKPROBE(\name) + .endm + +THUNK preempt_schedule_thunk, preempt_schedule +THUNK preempt_schedule_notrace_thunk, preempt_schedule_notrace +EXPORT_SYMBOL(preempt_schedule_thunk) +EXPORT_SYMBOL(preempt_schedule_notrace_thunk) diff --git a/arch/x86/include/asm/alternative.h b/arch/x86/include/asm/alternative.h index d7da28fada87..6c15a622ad60 100644 --- a/arch/x86/include/asm/alternative.h +++ b/arch/x86/include/asm/alternative.h @@ -113,7 +113,6 @@ extern void callthunks_patch_builtin_calls(void); extern void callthunks_patch_module_calls(struct callthunk_sites *sites, struct module *mod); extern void *callthunks_translate_call_dest(void *dest); -extern bool is_callthunk(void *addr); extern int x86_call_depth_emit_accounting(u8 **pprog, void *func); #else static __always_inline void callthunks_patch_builtin_calls(void) {} @@ -124,10 +123,6 @@ static __always_inline void *callthunks_translate_call_dest(void *dest) { return dest; } -static __always_inline bool is_callthunk(void *addr) -{ - return false; -} static __always_inline int x86_call_depth_emit_accounting(u8 **pprog, void *func) { diff --git a/arch/x86/include/asm/unwind_hints.h b/arch/x86/include/asm/unwind_hints.h index 01cb9692b160..85cc57cb6539 100644 --- a/arch/x86/include/asm/unwind_hints.h +++ b/arch/x86/include/asm/unwind_hints.h @@ -76,9 +76,18 @@ #else +#define UNWIND_HINT_UNDEFINED \ + UNWIND_HINT(UNWIND_HINT_TYPE_UNDEFINED, 0, 0, 0) + #define UNWIND_HINT_FUNC \ UNWIND_HINT(UNWIND_HINT_TYPE_FUNC, ORC_REG_SP, 8, 0) +#define UNWIND_HINT_SAVE \ + UNWIND_HINT(UNWIND_HINT_TYPE_SAVE, 0, 0, 0) + +#define UNWIND_HINT_RESTORE \ + UNWIND_HINT(UNWIND_HINT_TYPE_RESTORE, 0, 0, 0) + #endif /* __ASSEMBLY__ */ #endif /* _ASM_X86_UNWIND_HINTS_H */ diff --git a/arch/x86/kernel/callthunks.c b/arch/x86/kernel/callthunks.c index 8bb937331acb..c06bfc086565 100644 --- a/arch/x86/kernel/callthunks.c +++ b/arch/x86/kernel/callthunks.c @@ -293,7 +293,8 @@ void *callthunks_translate_call_dest(void *dest) return target ? : dest; } -bool is_callthunk(void *addr) +#ifdef CONFIG_BPF_JIT +static bool is_callthunk(void *addr) { unsigned int tmpl_size = SKL_TMPL_SIZE; void *tmpl = skl_call_thunk_template; @@ -306,7 +307,6 @@ bool is_callthunk(void *addr) return !bcmp((void *)(dest - tmpl_size), tmpl, tmpl_size); } -#ifdef CONFIG_BPF_JIT int x86_call_depth_emit_accounting(u8 **pprog, void *func) { unsigned int tmpl_size = SKL_TMPL_SIZE; diff --git a/arch/x86/kernel/unwind_orc.c b/arch/x86/kernel/unwind_orc.c index 4d8e518365f4..7e574cf3bf8a 100644 --- a/arch/x86/kernel/unwind_orc.c +++ b/arch/x86/kernel/unwind_orc.c @@ -16,8 +16,14 @@ ORC_HEADER; #define orc_warn_current(args...) \ ({ \ - if (state->task == current && !state->error) \ + static bool dumped_before; \ + if (state->task == current && !state->error) { \ orc_warn(args); \ + if (unwind_debug && !dumped_before) { \ + dumped_before = true; \ + unwind_dump(state); \ + } \ + } \ }) extern int __start_orc_unwind_ip[]; @@ -26,8 +32,49 @@ extern struct orc_entry __start_orc_unwind[]; extern struct orc_entry __stop_orc_unwind[]; static bool orc_init __ro_after_init; +static bool unwind_debug __ro_after_init; static unsigned int lookup_num_blocks __ro_after_init; +static int __init unwind_debug_cmdline(char *str) +{ + unwind_debug = true; + + return 0; +} +early_param("unwind_debug", unwind_debug_cmdline); + +static void unwind_dump(struct unwind_state *state) +{ + static bool dumped_before; + unsigned long word, *sp; + struct stack_info stack_info = {0}; + unsigned long visit_mask = 0; + + if (dumped_before) + return; + + dumped_before = true; + + printk_deferred("unwind stack type:%d next_sp:%p mask:0x%lx graph_idx:%d\n", + state->stack_info.type, state->stack_info.next_sp, + state->stack_mask, state->graph_idx); + + for (sp = __builtin_frame_address(0); sp; + sp = PTR_ALIGN(stack_info.next_sp, sizeof(long))) { + if (get_stack_info(sp, state->task, &stack_info, &visit_mask)) + break; + + for (; sp < stack_info.end; sp++) { + + word = READ_ONCE_NOCHECK(*sp); + + printk_deferred("%0*lx: %0*lx (%pB)\n", BITS_PER_LONG/4, + (unsigned long)sp, BITS_PER_LONG/4, + word, (void *)word); + } + } +} + static inline unsigned long orc_ip(const int *ip) { return (unsigned long)ip + *ip; @@ -139,21 +186,6 @@ static struct orc_entry null_orc_entry = { .type = ORC_TYPE_CALL }; -#ifdef CONFIG_CALL_THUNKS -static struct orc_entry *orc_callthunk_find(unsigned long ip) -{ - if (!is_callthunk((void *)ip)) - return NULL; - - return &null_orc_entry; -} -#else -static struct orc_entry *orc_callthunk_find(unsigned long ip) -{ - return NULL; -} -#endif - /* Fake frame pointer entry -- used as a fallback for generated code */ static struct orc_entry orc_fp_entry = { .type = ORC_TYPE_CALL, @@ -206,11 +238,7 @@ static struct orc_entry *orc_find(unsigned long ip) if (orc) return orc; - orc = orc_ftrace_find(ip); - if (orc) - return orc; - - return orc_callthunk_find(ip); + return orc_ftrace_find(ip); } #ifdef CONFIG_MODULES @@ -222,7 +250,6 @@ static struct orc_entry *cur_orc_table = __start_orc_unwind; static void orc_sort_swap(void *_a, void *_b, int size) { struct orc_entry *orc_a, *orc_b; - struct orc_entry orc_tmp; int *a = _a, *b = _b, tmp; int delta = _b - _a; @@ -234,9 +261,7 @@ static void orc_sort_swap(void *_a, void *_b, int size) /* Swap the corresponding .orc_unwind entries: */ orc_a = cur_orc_table + (a - cur_orc_ip_table); orc_b = cur_orc_table + (b - cur_orc_ip_table); - orc_tmp = *orc_a; - *orc_a = *orc_b; - *orc_b = orc_tmp; + swap(*orc_a, *orc_b); } static int orc_sort_cmp(const void *_a, const void *_b) diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_msg_x86.h b/drivers/gpu/drm/vmwgfx/vmwgfx_msg_x86.h index 0b74ca2dfb7b..23899d743a90 100644 --- a/drivers/gpu/drm/vmwgfx/vmwgfx_msg_x86.h +++ b/drivers/gpu/drm/vmwgfx/vmwgfx_msg_x86.h @@ -105,10 +105,14 @@ flags, magic, bp, \ eax, ebx, ecx, edx, si, di) \ ({ \ - asm volatile ("push %%rbp;" \ + asm volatile ( \ + UNWIND_HINT_SAVE \ + "push %%rbp;" \ + UNWIND_HINT_UNDEFINED \ "mov %12, %%rbp;" \ VMWARE_HYPERCALL_HB_OUT \ - "pop %%rbp;" : \ + "pop %%rbp;" \ + UNWIND_HINT_RESTORE : \ "=a"(eax), \ "=b"(ebx), \ "=c"(ecx), \ @@ -130,10 +134,14 @@ flags, magic, bp, \ eax, ebx, ecx, edx, si, di) \ ({ \ - asm volatile ("push %%rbp;" \ + asm volatile ( \ + UNWIND_HINT_SAVE \ + "push %%rbp;" \ + UNWIND_HINT_UNDEFINED \ "mov %12, %%rbp;" \ VMWARE_HYPERCALL_HB_IN \ - "pop %%rbp" : \ + "pop %%rbp;" \ + UNWIND_HINT_RESTORE : \ "=a"(eax), \ "=b"(ebx), \ "=c"(ecx), \ diff --git a/drivers/misc/lkdtm/bugs.c b/drivers/misc/lkdtm/bugs.c index 48821f4c2b21..92110cb6a0eb 100644 --- a/drivers/misc/lkdtm/bugs.c +++ b/drivers/misc/lkdtm/bugs.c @@ -487,6 +487,7 @@ static void lkdtm_UNSET_SMEP(void) * the cr4 writing instruction. */ insn = (unsigned char *)native_write_cr4; + OPTIMIZER_HIDE_VAR(insn); for (i = 0; i < MOV_CR4_DEPTH; i++) { /* mov %rdi, %cr4 */ if (insn[i] == 0x0f && insn[i+1] == 0x22 && insn[i+2] == 0xe7) diff --git a/include/linux/compiler_attributes.h b/include/linux/compiler_attributes.h index e659cb6fded3..84864767a56a 100644 --- a/include/linux/compiler_attributes.h +++ b/include/linux/compiler_attributes.h @@ -256,6 +256,18 @@ #define __noreturn __attribute__((__noreturn__)) /* + * Optional: only supported since GCC >= 11.1, clang >= 7.0. + * + * gcc: https://gcc.gnu.org/onlinedocs/gcc/Common-Function-Attributes.html#index-no_005fstack_005fprotector-function-attribute + * clang: https://clang.llvm.org/docs/AttributeReference.html#no-stack-protector-safebuffers + */ +#if __has_attribute(__no_stack_protector__) +# define __no_stack_protector __attribute__((__no_stack_protector__)) +#else +# define __no_stack_protector +#endif + +/* * Optional: not supported by gcc. * * clang: https://clang.llvm.org/docs/AttributeReference.html#overloadable diff --git a/init/main.c b/init/main.c index 32c65f28d84a..0d2cceff9993 100644 --- a/init/main.c +++ b/init/main.c @@ -873,7 +873,8 @@ static void __init print_unknown_bootoptions(void) memblock_free(unknown_options, len); } -asmlinkage __visible void __init __no_sanitize_address __noreturn start_kernel(void) +asmlinkage __visible __init __no_sanitize_address __noreturn __no_stack_protector +void start_kernel(void) { char *command_line; char *after_dashes; @@ -1073,7 +1074,13 @@ asmlinkage __visible void __init __no_sanitize_address __noreturn start_kernel(v /* Do the rest non-__init'ed, we're now alive */ arch_call_rest_init(); + /* + * Avoid stack canaries in callers of boot_init_stack_canary for gcc-10 + * and older. + */ +#if !__has_attribute(__no_stack_protector__) prevent_tail_call_optimization(); +#endif } /* Call all constructor functions linked into the kernel. */ diff --git a/tools/lib/subcmd/parse-options.h b/tools/lib/subcmd/parse-options.h index 41b9b942504d..8e9147358a28 100644 --- a/tools/lib/subcmd/parse-options.h +++ b/tools/lib/subcmd/parse-options.h @@ -6,10 +6,6 @@ #include <stdbool.h> #include <stdint.h> -#ifndef NORETURN -#define NORETURN __attribute__((__noreturn__)) -#endif - enum parse_opt_type { /* special types */ OPTION_END, @@ -183,9 +179,9 @@ extern int parse_options_subcommand(int argc, const char **argv, const char *const subcommands[], const char *usagestr[], int flags); -extern NORETURN void usage_with_options(const char * const *usagestr, +extern __noreturn void usage_with_options(const char * const *usagestr, const struct option *options); -extern NORETURN __attribute__((format(printf,3,4))) +extern __noreturn __attribute__((format(printf,3,4))) void usage_with_options_msg(const char * const *usagestr, const struct option *options, const char *fmt, ...); diff --git a/tools/lib/subcmd/subcmd-util.h b/tools/lib/subcmd/subcmd-util.h index b2aec04fce8f..dfac76e35ac7 100644 --- a/tools/lib/subcmd/subcmd-util.h +++ b/tools/lib/subcmd/subcmd-util.h @@ -5,8 +5,7 @@ #include <stdarg.h> #include <stdlib.h> #include <stdio.h> - -#define NORETURN __attribute__((__noreturn__)) +#include <linux/compiler.h> static inline void report(const char *prefix, const char *err, va_list params) { @@ -15,7 +14,7 @@ static inline void report(const char *prefix, const char *err, va_list params) fprintf(stderr, " %s%s\n", prefix, msg); } -static NORETURN inline void die(const char *err, ...) +static __noreturn inline void die(const char *err, ...) { va_list params; diff --git a/tools/objtool/Documentation/objtool.txt b/tools/objtool/Documentation/objtool.txt index 744db4218e7a..fe39c2a8ef0d 100644 --- a/tools/objtool/Documentation/objtool.txt +++ b/tools/objtool/Documentation/objtool.txt @@ -244,6 +244,11 @@ To achieve the validation, objtool enforces the following rules: Objtool warnings ---------------- +NOTE: When requesting help with an objtool warning, please recreate with +OBJTOOL_VERBOSE=1 (e.g., "make OBJTOOL_VERBOSE=1") and send the full +output, including any disassembly or backtrace below the warning, to the +objtool maintainers. + For asm files, if you're getting an error which doesn't make sense, first make sure that the affected code follows the above rules. @@ -298,6 +303,11 @@ the objtool maintainers. If it's not actually in a callable function (e.g. kernel entry code), change ENDPROC to END. +3. file.o: warning: objtool: foo+0x48c: bar() is missing a __noreturn annotation + + The call from foo() to bar() doesn't return, but bar() is missing the + __noreturn annotation. NOTE: In addition to annotating the function + with __noreturn, please also add it to tools/objtool/noreturns.h. 4. file.o: warning: objtool: func(): can't find starting instruction or diff --git a/tools/objtool/arch/powerpc/include/arch/elf.h b/tools/objtool/arch/powerpc/include/arch/elf.h index 73f9ae172fe5..66814fa28024 100644 --- a/tools/objtool/arch/powerpc/include/arch/elf.h +++ b/tools/objtool/arch/powerpc/include/arch/elf.h @@ -1,10 +1,13 @@ /* SPDX-License-Identifier: GPL-2.0-or-later */ - #ifndef _OBJTOOL_ARCH_ELF #define _OBJTOOL_ARCH_ELF -#define R_NONE R_PPC_NONE -#define R_ABS64 R_PPC64_ADDR64 -#define R_ABS32 R_PPC_ADDR32 +#define R_NONE R_PPC_NONE +#define R_ABS64 R_PPC64_ADDR64 +#define R_ABS32 R_PPC_ADDR32 +#define R_DATA32 R_PPC_REL32 +#define R_DATA64 R_PPC64_REL64 +#define R_TEXT32 R_PPC_REL32 +#define R_TEXT64 R_PPC64_REL32 #endif /* _OBJTOOL_ARCH_ELF */ diff --git a/tools/objtool/arch/x86/decode.c b/tools/objtool/arch/x86/decode.c index 9ef024fd648c..2e1caabecb18 100644 --- a/tools/objtool/arch/x86/decode.c +++ b/tools/objtool/arch/x86/decode.c @@ -84,7 +84,7 @@ bool arch_pc_relative_reloc(struct reloc *reloc) * All relocation types where P (the address of the target) * is included in the computation. */ - switch (reloc->type) { + switch (reloc_type(reloc)) { case R_X86_64_PC8: case R_X86_64_PC16: case R_X86_64_PC32: @@ -623,11 +623,11 @@ int arch_decode_instruction(struct objtool_file *file, const struct section *sec if (!immr || strcmp(immr->sym->name, "pv_ops")) break; - idx = (immr->addend + 8) / sizeof(void *); + idx = (reloc_addend(immr) + 8) / sizeof(void *); func = disp->sym; if (disp->sym->type == STT_SECTION) - func = find_symbol_by_offset(disp->sym->sec, disp->addend); + func = find_symbol_by_offset(disp->sym->sec, reloc_addend(disp)); if (!func) { WARN("no func for pv_ops[]"); return -1; diff --git a/tools/objtool/arch/x86/include/arch/elf.h b/tools/objtool/arch/x86/include/arch/elf.h index ac14987cf687..7131f7f51a4e 100644 --- a/tools/objtool/arch/x86/include/arch/elf.h +++ b/tools/objtool/arch/x86/include/arch/elf.h @@ -1,8 +1,13 @@ +/* SPDX-License-Identifier: GPL-2.0-or-later */ #ifndef _OBJTOOL_ARCH_ELF #define _OBJTOOL_ARCH_ELF -#define R_NONE R_X86_64_NONE -#define R_ABS64 R_X86_64_64 -#define R_ABS32 R_X86_64_32 +#define R_NONE R_X86_64_NONE +#define R_ABS32 R_X86_64_32 +#define R_ABS64 R_X86_64_64 +#define R_DATA32 R_X86_64_PC32 +#define R_DATA64 R_X86_64_PC32 +#define R_TEXT32 R_X86_64_PC32 +#define R_TEXT64 R_X86_64_PC32 #endif /* _OBJTOOL_ARCH_ELF */ diff --git a/tools/objtool/arch/x86/special.c b/tools/objtool/arch/x86/special.c index 799ad6bb72e5..29e949579ede 100644 --- a/tools/objtool/arch/x86/special.c +++ b/tools/objtool/arch/x86/special.c @@ -99,10 +99,10 @@ struct reloc *arch_find_switch_table(struct objtool_file *file, !text_reloc->sym->sec->rodata) return NULL; - table_offset = text_reloc->addend; + table_offset = reloc_addend(text_reloc); table_sec = text_reloc->sym->sec; - if (text_reloc->type == R_X86_64_PC32) + if (reloc_type(text_reloc) == R_X86_64_PC32) table_offset += 4; /* @@ -132,7 +132,7 @@ struct reloc *arch_find_switch_table(struct objtool_file *file, * indicates a rare GCC quirk/bug which can leave dead * code behind. */ - if (text_reloc->type == R_X86_64_PC32) + if (reloc_type(text_reloc) == R_X86_64_PC32) file->ignore_unreachables = true; return rodata_reloc; diff --git a/tools/objtool/builtin-check.c b/tools/objtool/builtin-check.c index 7c175198d09f..5e21cfb7661d 100644 --- a/tools/objtool/builtin-check.c +++ b/tools/objtool/builtin-check.c @@ -93,6 +93,7 @@ static const struct option check_options[] = { OPT_BOOLEAN(0, "no-unreachable", &opts.no_unreachable, "skip 'unreachable instruction' warnings"), OPT_BOOLEAN(0, "sec-address", &opts.sec_address, "print section addresses in warnings"), OPT_BOOLEAN(0, "stats", &opts.stats, "print statistics"), + OPT_BOOLEAN('v', "verbose", &opts.verbose, "verbose warnings"), OPT_END(), }; @@ -118,6 +119,10 @@ int cmd_parse_options(int argc, const char **argv, const char * const usage[]) parse_options(envc, envv, check_options, env_usage, 0); } + env = getenv("OBJTOOL_VERBOSE"); + if (env && !strcmp(env, "1")) + opts.verbose = true; + argc = parse_options(argc, argv, check_options, usage, 0); if (argc != 1) usage_with_options(usage, check_options); diff --git a/tools/objtool/check.c b/tools/objtool/check.c index 9e3cc53a7f4c..8936a05f0e5a 100644 --- a/tools/objtool/check.c +++ b/tools/objtool/check.c @@ -8,7 +8,6 @@ #include <inttypes.h> #include <sys/mman.h> -#include <arch/elf.h> #include <objtool/builtin.h> #include <objtool/cfi.h> #include <objtool/arch.h> @@ -33,6 +32,7 @@ static unsigned long nr_cfi, nr_cfi_reused, nr_cfi_cache; static struct cfi_init_state initial_func_cfi; static struct cfi_state init_cfi; static struct cfi_state func_cfi; +static struct cfi_state force_undefined_cfi; struct instruction *find_insn(struct objtool_file *file, struct section *sec, unsigned long offset) @@ -192,51 +192,11 @@ static bool __dead_end_function(struct objtool_file *file, struct symbol *func, struct instruction *insn; bool empty = true; - /* - * Unfortunately these have to be hard coded because the noreturn - * attribute isn't provided in ELF data. Keep 'em sorted. - */ +#define NORETURN(func) __stringify(func), static const char * const global_noreturns[] = { - "__invalid_creds", - "__kunit_abort", - "__module_put_and_kthread_exit", - "__reiserfs_panic", - "__stack_chk_fail", - "__ubsan_handle_builtin_unreachable", - "arch_call_rest_init", - "arch_cpu_idle_dead", - "cpu_bringup_and_idle", - "cpu_startup_entry", - "do_exit", - "do_group_exit", - "do_task_dead", - "ex_handler_msr_mce", - "fortify_panic", - "hlt_play_dead", - "hv_ghcb_terminate", - "kthread_complete_and_exit", - "kthread_exit", - "kunit_try_catch_throw", - "lbug_with_loc", - "machine_real_restart", - "make_task_dead", - "mpt_halt_firmware", - "nmi_panic_self_stop", - "panic", - "panic_smp_self_stop", - "rest_init", - "resume_play_dead", - "rewind_stack_and_make_dead", - "sev_es_terminate", - "snp_abort", - "start_kernel", - "stop_this_cpu", - "usercopy_abort", - "x86_64_start_kernel", - "x86_64_start_reservations", - "xen_cpu_bringup_again", - "xen_start_kernel", +#include "noreturns.h" }; +#undef NORETURN if (!func) return false; @@ -533,7 +493,7 @@ static int add_pv_ops(struct objtool_file *file, const char *symname) { struct symbol *sym, *func; unsigned long off, end; - struct reloc *rel; + struct reloc *reloc; int idx; sym = find_symbol_by_name(file->elf, symname); @@ -543,19 +503,20 @@ static int add_pv_ops(struct objtool_file *file, const char *symname) off = sym->offset; end = off + sym->len; for (;;) { - rel = find_reloc_by_dest_range(file->elf, sym->sec, off, end - off); - if (!rel) + reloc = find_reloc_by_dest_range(file->elf, sym->sec, off, end - off); + if (!reloc) break; - func = rel->sym; + func = reloc->sym; if (func->type == STT_SECTION) - func = find_symbol_by_offset(rel->sym->sec, rel->addend); + func = find_symbol_by_offset(reloc->sym->sec, + reloc_addend(reloc)); - idx = (rel->offset - sym->offset) / sizeof(unsigned long); + idx = (reloc_offset(reloc) - sym->offset) / sizeof(unsigned long); objtool_pv_add(file, idx, func); - off = rel->offset + 1; + off = reloc_offset(reloc) + 1; if (off > end) break; } @@ -620,35 +581,40 @@ static struct instruction *find_last_insn(struct objtool_file *file, */ static int add_dead_ends(struct objtool_file *file) { - struct section *sec; + struct section *rsec; struct reloc *reloc; struct instruction *insn; + s64 addend; /* * Check for manually annotated dead ends. */ - sec = find_section_by_name(file->elf, ".rela.discard.unreachable"); - if (!sec) + rsec = find_section_by_name(file->elf, ".rela.discard.unreachable"); + if (!rsec) goto reachable; - list_for_each_entry(reloc, &sec->reloc_list, list) { + for_each_reloc(rsec, reloc) { + if (reloc->sym->type != STT_SECTION) { - WARN("unexpected relocation symbol type in %s", sec->name); + WARN("unexpected relocation symbol type in %s", rsec->name); return -1; } - insn = find_insn(file, reloc->sym->sec, reloc->addend); + + addend = reloc_addend(reloc); + + insn = find_insn(file, reloc->sym->sec, addend); if (insn) insn = prev_insn_same_sec(file, insn); - else if (reloc->addend == reloc->sym->sec->sh.sh_size) { + else if (addend == reloc->sym->sec->sh.sh_size) { insn = find_last_insn(file, reloc->sym->sec); if (!insn) { WARN("can't find unreachable insn at %s+0x%" PRIx64, - reloc->sym->sec->name, reloc->addend); + reloc->sym->sec->name, addend); return -1; } } else { WARN("can't find unreachable insn at %s+0x%" PRIx64, - reloc->sym->sec->name, reloc->addend); + reloc->sym->sec->name, addend); return -1; } @@ -662,28 +628,32 @@ reachable: * GCC doesn't know the "ud2" is fatal, so it generates code as if it's * not a dead end. */ - sec = find_section_by_name(file->elf, ".rela.discard.reachable"); - if (!sec) + rsec = find_section_by_name(file->elf, ".rela.discard.reachable"); + if (!rsec) return 0; - list_for_each_entry(reloc, &sec->reloc_list, list) { + for_each_reloc(rsec, reloc) { + if (reloc->sym->type != STT_SECTION) { - WARN("unexpected relocation symbol type in %s", sec->name); + WARN("unexpected relocation symbol type in %s", rsec->name); return -1; } - insn = find_insn(file, reloc->sym->sec, reloc->addend); + + addend = reloc_addend(reloc); + + insn = find_insn(file, reloc->sym->sec, addend); if (insn) insn = prev_insn_same_sec(file, insn); - else if (reloc->addend == reloc->sym->sec->sh.sh_size) { + else if (addend == reloc->sym->sec->sh.sh_size) { insn = find_last_insn(file, reloc->sym->sec); if (!insn) { WARN("can't find reachable insn at %s+0x%" PRIx64, - reloc->sym->sec->name, reloc->addend); + reloc->sym->sec->name, addend); return -1; } } else { WARN("can't find reachable insn at %s+0x%" PRIx64, - reloc->sym->sec->name, reloc->addend); + reloc->sym->sec->name, addend); return -1; } @@ -695,8 +665,8 @@ reachable: static int create_static_call_sections(struct objtool_file *file) { - struct section *sec; struct static_call_site *site; + struct section *sec; struct instruction *insn; struct symbol *key_sym; char *key_name, *tmp; @@ -716,22 +686,21 @@ static int create_static_call_sections(struct objtool_file *file) list_for_each_entry(insn, &file->static_call_list, call_node) idx++; - sec = elf_create_section(file->elf, ".static_call_sites", SHF_WRITE, - sizeof(struct static_call_site), idx); + sec = elf_create_section_pair(file->elf, ".static_call_sites", + sizeof(*site), idx, idx * 2); if (!sec) return -1; + /* Allow modules to modify the low bits of static_call_site::key */ + sec->sh.sh_flags |= SHF_WRITE; + idx = 0; list_for_each_entry(insn, &file->static_call_list, call_node) { - site = (struct static_call_site *)sec->data->d_buf + idx; - memset(site, 0, sizeof(struct static_call_site)); - /* populate reloc for 'addr' */ - if (elf_add_reloc_to_insn(file->elf, sec, - idx * sizeof(struct static_call_site), - R_X86_64_PC32, - insn->sec, insn->offset)) + if (!elf_init_reloc_text_sym(file->elf, sec, + idx * sizeof(*site), idx * 2, + insn->sec, insn->offset)) return -1; /* find key symbol */ @@ -771,10 +740,10 @@ static int create_static_call_sections(struct objtool_file *file) free(key_name); /* populate reloc for 'key' */ - if (elf_add_reloc(file->elf, sec, - idx * sizeof(struct static_call_site) + 4, - R_X86_64_PC32, key_sym, - is_sibling_call(insn) * STATIC_CALL_SITE_TAIL)) + if (!elf_init_reloc_data_sym(file->elf, sec, + idx * sizeof(*site) + 4, + (idx * 2) + 1, key_sym, + is_sibling_call(insn) * STATIC_CALL_SITE_TAIL)) return -1; idx++; @@ -802,26 +771,18 @@ static int create_retpoline_sites_sections(struct objtool_file *file) if (!idx) return 0; - sec = elf_create_section(file->elf, ".retpoline_sites", 0, - sizeof(int), idx); - if (!sec) { - WARN("elf_create_section: .retpoline_sites"); + sec = elf_create_section_pair(file->elf, ".retpoline_sites", + sizeof(int), idx, idx); + if (!sec) return -1; - } idx = 0; list_for_each_entry(insn, &file->retpoline_call_list, call_node) { - int *site = (int *)sec->data->d_buf + idx; - *site = 0; - - if (elf_add_reloc_to_insn(file->elf, sec, - idx * sizeof(int), - R_X86_64_PC32, - insn->sec, insn->offset)) { - WARN("elf_add_reloc_to_insn: .retpoline_sites"); + if (!elf_init_reloc_text_sym(file->elf, sec, + idx * sizeof(int), idx, + insn->sec, insn->offset)) return -1; - } idx++; } @@ -848,26 +809,18 @@ static int create_return_sites_sections(struct objtool_file *file) if (!idx) return 0; - sec = elf_create_section(file->elf, ".return_sites", 0, - sizeof(int), idx); - if (!sec) { - WARN("elf_create_section: .return_sites"); + sec = elf_create_section_pair(file->elf, ".return_sites", + sizeof(int), idx, idx); + if (!sec) return -1; - } idx = 0; list_for_each_entry(insn, &file->return_thunk_list, call_node) { - int *site = (int *)sec->data->d_buf + idx; - *site = 0; - - if (elf_add_reloc_to_insn(file->elf, sec, - idx * sizeof(int), - R_X86_64_PC32, - insn->sec, insn->offset)) { - WARN("elf_add_reloc_to_insn: .return_sites"); + if (!elf_init_reloc_text_sym(file->elf, sec, + idx * sizeof(int), idx, + insn->sec, insn->offset)) return -1; - } idx++; } @@ -900,12 +853,10 @@ static int create_ibt_endbr_seal_sections(struct objtool_file *file) if (!idx) return 0; - sec = elf_create_section(file->elf, ".ibt_endbr_seal", 0, - sizeof(int), idx); - if (!sec) { - WARN("elf_create_section: .ibt_endbr_seal"); + sec = elf_create_section_pair(file->elf, ".ibt_endbr_seal", + sizeof(int), idx, idx); + if (!sec) return -1; - } idx = 0; list_for_each_entry(insn, &file->endbr_list, call_node) { @@ -920,13 +871,10 @@ static int create_ibt_endbr_seal_sections(struct objtool_file *file) !strcmp(sym->name, "cleanup_module"))) WARN("%s(): not an indirect call target", sym->name); - if (elf_add_reloc_to_insn(file->elf, sec, - idx * sizeof(int), - R_X86_64_PC32, - insn->sec, insn->offset)) { - WARN("elf_add_reloc_to_insn: .ibt_endbr_seal"); + if (!elf_init_reloc_text_sym(file->elf, sec, + idx * sizeof(int), idx, + insn->sec, insn->offset)) return -1; - } idx++; } @@ -938,7 +886,6 @@ static int create_cfi_sections(struct objtool_file *file) { struct section *sec; struct symbol *sym; - unsigned int *loc; int idx; sec = find_section_by_name(file->elf, ".cfi_sites"); @@ -959,7 +906,8 @@ static int create_cfi_sections(struct objtool_file *file) idx++; } - sec = elf_create_section(file->elf, ".cfi_sites", 0, sizeof(unsigned int), idx); + sec = elf_create_section_pair(file->elf, ".cfi_sites", + sizeof(unsigned int), idx, idx); if (!sec) return -1; @@ -971,13 +919,9 @@ static int create_cfi_sections(struct objtool_file *file) if (strncmp(sym->name, "__cfi_", 6)) continue; - loc = (unsigned int *)sec->data->d_buf + idx; - memset(loc, 0, sizeof(unsigned int)); - - if (elf_add_reloc_to_insn(file->elf, sec, - idx * sizeof(unsigned int), - R_X86_64_PC32, - sym->sec, sym->offset)) + if (!elf_init_reloc_text_sym(file->elf, sec, + idx * sizeof(unsigned int), idx, + sym->sec, sym->offset)) return -1; idx++; @@ -988,7 +932,7 @@ static int create_cfi_sections(struct objtool_file *file) static int create_mcount_loc_sections(struct objtool_file *file) { - int addrsize = elf_class_addrsize(file->elf); + size_t addr_size = elf_addr_size(file->elf); struct instruction *insn; struct section *sec; int idx; @@ -1007,25 +951,26 @@ static int create_mcount_loc_sections(struct objtool_file *file) list_for_each_entry(insn, &file->mcount_loc_list, call_node) idx++; - sec = elf_create_section(file->elf, "__mcount_loc", 0, addrsize, idx); + sec = elf_create_section_pair(file->elf, "__mcount_loc", addr_size, + idx, idx); if (!sec) return -1; - sec->sh.sh_addralign = addrsize; + sec->sh.sh_addralign = addr_size; idx = 0; list_for_each_entry(insn, &file->mcount_loc_list, call_node) { - void *loc; - loc = sec->data->d_buf + idx; - memset(loc, 0, addrsize); + struct reloc *reloc; - if (elf_add_reloc_to_insn(file->elf, sec, idx, - addrsize == sizeof(u64) ? R_ABS64 : R_ABS32, - insn->sec, insn->offset)) + reloc = elf_init_reloc_text_sym(file->elf, sec, idx * addr_size, idx, + insn->sec, insn->offset); + if (!reloc) return -1; - idx += addrsize; + set_reloc_type(file->elf, reloc, addr_size == 8 ? R_ABS64 : R_ABS32); + + idx++; } return 0; @@ -1035,7 +980,6 @@ static int create_direct_call_sections(struct objtool_file *file) { struct instruction *insn; struct section *sec; - unsigned int *loc; int idx; sec = find_section_by_name(file->elf, ".call_sites"); @@ -1052,20 +996,17 @@ static int create_direct_call_sections(struct objtool_file *file) list_for_each_entry(insn, &file->call_list, call_node) idx++; - sec = elf_create_section(file->elf, ".call_sites", 0, sizeof(unsigned int), idx); + sec = elf_create_section_pair(file->elf, ".call_sites", + sizeof(unsigned int), idx, idx); if (!sec) return -1; idx = 0; list_for_each_entry(insn, &file->call_list, call_node) { - loc = (unsigned int *)sec->data->d_buf + idx; - memset(loc, 0, sizeof(unsigned int)); - - if (elf_add_reloc_to_insn(file->elf, sec, - idx * sizeof(unsigned int), - R_X86_64_PC32, - insn->sec, insn->offset)) + if (!elf_init_reloc_text_sym(file->elf, sec, + idx * sizeof(unsigned int), idx, + insn->sec, insn->offset)) return -1; idx++; @@ -1080,28 +1021,29 @@ static int create_direct_call_sections(struct objtool_file *file) static void add_ignores(struct objtool_file *file) { struct instruction *insn; - struct section *sec; + struct section *rsec; struct symbol *func; struct reloc *reloc; - sec = find_section_by_name(file->elf, ".rela.discard.func_stack_frame_non_standard"); - if (!sec) + rsec = find_section_by_name(file->elf, ".rela.discard.func_stack_frame_non_standard"); + if (!rsec) return; - list_for_each_entry(reloc, &sec->reloc_list, list) { + for_each_reloc(rsec, reloc) { switch (reloc->sym->type) { case STT_FUNC: func = reloc->sym; break; case STT_SECTION: - func = find_func_by_offset(reloc->sym->sec, reloc->addend); + func = find_func_by_offset(reloc->sym->sec, reloc_addend(reloc)); if (!func) continue; break; default: - WARN("unexpected relocation symbol type in %s: %d", sec->name, reloc->sym->type); + WARN("unexpected relocation symbol type in %s: %d", + rsec->name, reloc->sym->type); continue; } @@ -1320,21 +1262,21 @@ static void add_uaccess_safe(struct objtool_file *file) */ static int add_ignore_alternatives(struct objtool_file *file) { - struct section *sec; + struct section *rsec; struct reloc *reloc; struct instruction *insn; - sec = find_section_by_name(file->elf, ".rela.discard.ignore_alts"); - if (!sec) + rsec = find_section_by_name(file->elf, ".rela.discard.ignore_alts"); + if (!rsec) return 0; - list_for_each_entry(reloc, &sec->reloc_list, list) { + for_each_reloc(rsec, reloc) { if (reloc->sym->type != STT_SECTION) { - WARN("unexpected relocation symbol type in %s", sec->name); + WARN("unexpected relocation symbol type in %s", rsec->name); return -1; } - insn = find_insn(file, reloc->sym->sec, reloc->addend); + insn = find_insn(file, reloc->sym->sec, reloc_addend(reloc)); if (!insn) { WARN("bad .discard.ignore_alts entry"); return -1; @@ -1421,10 +1363,8 @@ static void annotate_call_site(struct objtool_file *file, * noinstr text. */ if (opts.hack_noinstr && insn->sec->noinstr && sym->profiling_func) { - if (reloc) { - reloc->type = R_NONE; - elf_write_reloc(file->elf, reloc); - } + if (reloc) + set_reloc_type(file->elf, reloc, R_NONE); elf_write_insn(file->elf, insn->sec, insn->offset, insn->len, @@ -1450,10 +1390,8 @@ static void annotate_call_site(struct objtool_file *file, if (sibling) WARN_INSN(insn, "tail call to __fentry__ !?!?"); if (opts.mnop) { - if (reloc) { - reloc->type = R_NONE; - elf_write_reloc(file->elf, reloc); - } + if (reloc) + set_reloc_type(file->elf, reloc, R_NONE); elf_write_insn(file->elf, insn->sec, insn->offset, insn->len, @@ -1610,7 +1548,7 @@ static int add_jump_destinations(struct objtool_file *file) dest_off = arch_jump_destination(insn); } else if (reloc->sym->type == STT_SECTION) { dest_sec = reloc->sym->sec; - dest_off = arch_dest_reloc_offset(reloc->addend); + dest_off = arch_dest_reloc_offset(reloc_addend(reloc)); } else if (reloc->sym->retpoline_thunk) { add_retpoline_call(file, insn); continue; @@ -1627,7 +1565,7 @@ static int add_jump_destinations(struct objtool_file *file) } else if (reloc->sym->sec->idx) { dest_sec = reloc->sym->sec; dest_off = reloc->sym->sym.st_value + - arch_dest_reloc_offset(reloc->addend); + arch_dest_reloc_offset(reloc_addend(reloc)); } else { /* non-func asm code jumping to another file */ continue; @@ -1744,7 +1682,7 @@ static int add_call_destinations(struct objtool_file *file) } } else if (reloc->sym->type == STT_SECTION) { - dest_off = arch_dest_reloc_offset(reloc->addend); + dest_off = arch_dest_reloc_offset(reloc_addend(reloc)); dest = find_call_destination(reloc->sym->sec, dest_off); if (!dest) { WARN_INSN(insn, "can't find call dest symbol at %s+0x%lx", @@ -1932,10 +1870,8 @@ static int handle_jump_alt(struct objtool_file *file, if (opts.hack_jump_label && special_alt->key_addend & 2) { struct reloc *reloc = insn_reloc(file, orig_insn); - if (reloc) { - reloc->type = R_NONE; - elf_write_reloc(file->elf, reloc); - } + if (reloc) + set_reloc_type(file->elf, reloc, R_NONE); elf_write_insn(file->elf, orig_insn->sec, orig_insn->offset, orig_insn->len, arch_nop_insn(orig_insn->len)); @@ -2047,34 +1983,35 @@ out: } static int add_jump_table(struct objtool_file *file, struct instruction *insn, - struct reloc *table) + struct reloc *next_table) { - struct reloc *reloc = table; - struct instruction *dest_insn; - struct alternative *alt; struct symbol *pfunc = insn_func(insn)->pfunc; + struct reloc *table = insn_jump_table(insn); + struct instruction *dest_insn; unsigned int prev_offset = 0; + struct reloc *reloc = table; + struct alternative *alt; /* * Each @reloc is a switch table relocation which points to the target * instruction. */ - list_for_each_entry_from(reloc, &table->sec->reloc_list, list) { + for_each_reloc_from(table->sec, reloc) { /* Check for the end of the table: */ - if (reloc != table && reloc->jump_table_start) + if (reloc != table && reloc == next_table) break; /* Make sure the table entries are consecutive: */ - if (prev_offset && reloc->offset != prev_offset + 8) + if (prev_offset && reloc_offset(reloc) != prev_offset + 8) break; /* Detect function pointers from contiguous objects: */ if (reloc->sym->sec == pfunc->sec && - reloc->addend == pfunc->offset) + reloc_addend(reloc) == pfunc->offset) break; - dest_insn = find_insn(file, reloc->sym->sec, reloc->addend); + dest_insn = find_insn(file, reloc->sym->sec, reloc_addend(reloc)); if (!dest_insn) break; @@ -2091,7 +2028,7 @@ static int add_jump_table(struct objtool_file *file, struct instruction *insn, alt->insn = dest_insn; alt->next = insn->alts; insn->alts = alt; - prev_offset = reloc->offset; + prev_offset = reloc_offset(reloc); } if (!prev_offset) { @@ -2135,7 +2072,7 @@ static struct reloc *find_jump_table(struct objtool_file *file, table_reloc = arch_find_switch_table(file, insn); if (!table_reloc) continue; - dest_insn = find_insn(file, table_reloc->sym->sec, table_reloc->addend); + dest_insn = find_insn(file, table_reloc->sym->sec, reloc_addend(table_reloc)); if (!dest_insn || !insn_func(dest_insn) || insn_func(dest_insn)->pfunc != func) continue; @@ -2177,29 +2114,39 @@ static void mark_func_jump_tables(struct objtool_file *file, continue; reloc = find_jump_table(file, func, insn); - if (reloc) { - reloc->jump_table_start = true; + if (reloc) insn->_jump_table = reloc; - } } } static int add_func_jump_tables(struct objtool_file *file, struct symbol *func) { - struct instruction *insn; - int ret; + struct instruction *insn, *insn_t1 = NULL, *insn_t2; + int ret = 0; func_for_each_insn(file, func, insn) { if (!insn_jump_table(insn)) continue; - ret = add_jump_table(file, insn, insn_jump_table(insn)); + if (!insn_t1) { + insn_t1 = insn; + continue; + } + + insn_t2 = insn; + + ret = add_jump_table(file, insn_t1, insn_jump_table(insn_t2)); if (ret) return ret; + + insn_t1 = insn_t2; } - return 0; + if (insn_t1) + ret = add_jump_table(file, insn_t1, NULL); + + return ret; } /* @@ -2240,7 +2187,7 @@ static void set_func_state(struct cfi_state *state) static int read_unwind_hints(struct objtool_file *file) { struct cfi_state cfi = init_cfi; - struct section *sec, *relocsec; + struct section *sec; struct unwind_hint *hint; struct instruction *insn; struct reloc *reloc; @@ -2250,8 +2197,7 @@ static int read_unwind_hints(struct objtool_file *file) if (!sec) return 0; - relocsec = sec->reloc; - if (!relocsec) { + if (!sec->rsec) { WARN("missing .rela.discard.unwind_hints section"); return -1; } @@ -2272,7 +2218,7 @@ static int read_unwind_hints(struct objtool_file *file) return -1; } - insn = find_insn(file, reloc->sym->sec, reloc->addend); + insn = find_insn(file, reloc->sym->sec, reloc_addend(reloc)); if (!insn) { WARN("can't find insn for unwind_hints[%d]", i); return -1; @@ -2280,6 +2226,11 @@ static int read_unwind_hints(struct objtool_file *file) insn->hint = true; + if (hint->type == UNWIND_HINT_TYPE_UNDEFINED) { + insn->cfi = &force_undefined_cfi; + continue; + } + if (hint->type == UNWIND_HINT_TYPE_SAVE) { insn->hint = false; insn->save = true; @@ -2326,16 +2277,17 @@ static int read_unwind_hints(struct objtool_file *file) static int read_noendbr_hints(struct objtool_file *file) { - struct section *sec; struct instruction *insn; + struct section *rsec; struct reloc *reloc; - sec = find_section_by_name(file->elf, ".rela.discard.noendbr"); - if (!sec) + rsec = find_section_by_name(file->elf, ".rela.discard.noendbr"); + if (!rsec) return 0; - list_for_each_entry(reloc, &sec->reloc_list, list) { - insn = find_insn(file, reloc->sym->sec, reloc->sym->offset + reloc->addend); + for_each_reloc(rsec, reloc) { + insn = find_insn(file, reloc->sym->sec, + reloc->sym->offset + reloc_addend(reloc)); if (!insn) { WARN("bad .discard.noendbr entry"); return -1; @@ -2349,21 +2301,21 @@ static int read_noendbr_hints(struct objtool_file *file) static int read_retpoline_hints(struct objtool_file *file) { - struct section *sec; + struct section *rsec; struct instruction *insn; struct reloc *reloc; - sec = find_section_by_name(file->elf, ".rela.discard.retpoline_safe"); - if (!sec) + rsec = find_section_by_name(file->elf, ".rela.discard.retpoline_safe"); + if (!rsec) return 0; - list_for_each_entry(reloc, &sec->reloc_list, list) { + for_each_reloc(rsec, reloc) { if (reloc->sym->type != STT_SECTION) { - WARN("unexpected relocation symbol type in %s", sec->name); + WARN("unexpected relocation symbol type in %s", rsec->name); return -1; } - insn = find_insn(file, reloc->sym->sec, reloc->addend); + insn = find_insn(file, reloc->sym->sec, reloc_addend(reloc)); if (!insn) { WARN("bad .discard.retpoline_safe entry"); return -1; @@ -2385,21 +2337,21 @@ static int read_retpoline_hints(struct objtool_file *file) static int read_instr_hints(struct objtool_file *file) { - struct section *sec; + struct section *rsec; struct instruction *insn; struct reloc *reloc; - sec = find_section_by_name(file->elf, ".rela.discard.instr_end"); - if (!sec) + rsec = find_section_by_name(file->elf, ".rela.discard.instr_end"); + if (!rsec) return 0; - list_for_each_entry(reloc, &sec->reloc_list, list) { + for_each_reloc(rsec, reloc) { if (reloc->sym->type != STT_SECTION) { - WARN("unexpected relocation symbol type in %s", sec->name); + WARN("unexpected relocation symbol type in %s", rsec->name); return -1; } - insn = find_insn(file, reloc->sym->sec, reloc->addend); + insn = find_insn(file, reloc->sym->sec, reloc_addend(reloc)); if (!insn) { WARN("bad .discard.instr_end entry"); return -1; @@ -2408,17 +2360,17 @@ static int read_instr_hints(struct objtool_file *file) insn->instr--; } - sec = find_section_by_name(file->elf, ".rela.discard.instr_begin"); - if (!sec) + rsec = find_section_by_name(file->elf, ".rela.discard.instr_begin"); + if (!rsec) return 0; - list_for_each_entry(reloc, &sec->reloc_list, list) { + for_each_reloc(rsec, reloc) { if (reloc->sym->type != STT_SECTION) { - WARN("unexpected relocation symbol type in %s", sec->name); + WARN("unexpected relocation symbol type in %s", rsec->name); return -1; } - insn = find_insn(file, reloc->sym->sec, reloc->addend); + insn = find_insn(file, reloc->sym->sec, reloc_addend(reloc)); if (!insn) { WARN("bad .discard.instr_begin entry"); return -1; @@ -2432,21 +2384,21 @@ static int read_instr_hints(struct objtool_file *file) static int read_validate_unret_hints(struct objtool_file *file) { - struct section *sec; + struct section *rsec; struct instruction *insn; struct reloc *reloc; - sec = find_section_by_name(file->elf, ".rela.discard.validate_unret"); - if (!sec) + rsec = find_section_by_name(file->elf, ".rela.discard.validate_unret"); + if (!rsec) return 0; - list_for_each_entry(reloc, &sec->reloc_list, list) { + for_each_reloc(rsec, reloc) { if (reloc->sym->type != STT_SECTION) { - WARN("unexpected relocation symbol type in %s", sec->name); + WARN("unexpected relocation symbol type in %s", rsec->name); return -1; } - insn = find_insn(file, reloc->sym->sec, reloc->addend); + insn = find_insn(file, reloc->sym->sec, reloc_addend(reloc)); if (!insn) { WARN("bad .discard.instr_end entry"); return -1; @@ -2461,23 +2413,23 @@ static int read_validate_unret_hints(struct objtool_file *file) static int read_intra_function_calls(struct objtool_file *file) { struct instruction *insn; - struct section *sec; + struct section *rsec; struct reloc *reloc; - sec = find_section_by_name(file->elf, ".rela.discard.intra_function_calls"); - if (!sec) + rsec = find_section_by_name(file->elf, ".rela.discard.intra_function_calls"); + if (!rsec) return 0; - list_for_each_entry(reloc, &sec->reloc_list, list) { + for_each_reloc(rsec, reloc) { unsigned long dest_off; if (reloc->sym->type != STT_SECTION) { WARN("unexpected relocation symbol type in %s", - sec->name); + rsec->name); return -1; } - insn = find_insn(file, reloc->sym->sec, reloc->addend); + insn = find_insn(file, reloc->sym->sec, reloc_addend(reloc)); if (!insn) { WARN("bad .discard.intra_function_call entry"); return -1; @@ -2833,6 +2785,10 @@ static int update_cfi_state(struct instruction *insn, struct cfi_reg *cfa = &cfi->cfa; struct cfi_reg *regs = cfi->regs; + /* ignore UNWIND_HINT_UNDEFINED regions */ + if (cfi->force_undefined) + return 0; + /* stack operations don't make sense with an undefined CFA */ if (cfa->base == CFI_UNDEFINED) { if (insn_func(insn)) { @@ -3369,15 +3325,15 @@ static inline bool func_uaccess_safe(struct symbol *func) static inline const char *call_dest_name(struct instruction *insn) { static char pvname[19]; - struct reloc *rel; + struct reloc *reloc; int idx; if (insn_call_dest(insn)) return insn_call_dest(insn)->name; - rel = insn_reloc(NULL, insn); - if (rel && !strcmp(rel->sym->name, "pv_ops")) { - idx = (rel->addend / sizeof(void *)); + reloc = insn_reloc(NULL, insn); + if (reloc && !strcmp(reloc->sym->name, "pv_ops")) { + idx = (reloc_addend(reloc) / sizeof(void *)); snprintf(pvname, sizeof(pvname), "pv_ops[%d]", idx); return pvname; } @@ -3388,14 +3344,14 @@ static inline const char *call_dest_name(struct instruction *insn) static bool pv_call_dest(struct objtool_file *file, struct instruction *insn) { struct symbol *target; - struct reloc *rel; + struct reloc *reloc; int idx; - rel = insn_reloc(file, insn); - if (!rel || strcmp(rel->sym->name, "pv_ops")) + reloc = insn_reloc(file, insn); + if (!reloc || strcmp(reloc->sym->name, "pv_ops")) return false; - idx = (arch_dest_reloc_offset(rel->addend) / sizeof(void *)); + idx = (arch_dest_reloc_offset(reloc_addend(reloc)) / sizeof(void *)); if (file->pv_ops[idx].clean) return true; @@ -3657,8 +3613,7 @@ static int validate_branch(struct objtool_file *file, struct symbol *func, ret = validate_branch(file, func, alt->insn, state); if (ret) { - if (opts.backtrace) - BT_FUNC("(alt)", insn); + BT_INSN(insn, "(alt)"); return ret; } } @@ -3703,8 +3658,7 @@ static int validate_branch(struct objtool_file *file, struct symbol *func, ret = validate_branch(file, func, insn->jump_dest, state); if (ret) { - if (opts.backtrace) - BT_FUNC("(branch)", insn); + BT_INSN(insn, "(branch)"); return ret; } } @@ -3802,8 +3756,8 @@ static int validate_unwind_hint(struct objtool_file *file, { if (insn->hint && !insn->visited && !insn->ignore) { int ret = validate_branch(file, insn_func(insn), insn, *state); - if (ret && opts.backtrace) - BT_FUNC("<=== (hint)", insn); + if (ret) + BT_INSN(insn, "<=== (hint)"); return ret; } @@ -3841,7 +3795,7 @@ static int validate_unwind_hints(struct objtool_file *file, struct section *sec) static int validate_unret(struct objtool_file *file, struct instruction *insn) { struct instruction *next, *dest; - int ret, warnings = 0; + int ret; for (;;) { next = next_insn_to_validate(file, insn); @@ -3861,8 +3815,7 @@ static int validate_unret(struct objtool_file *file, struct instruction *insn) ret = validate_unret(file, alt->insn); if (ret) { - if (opts.backtrace) - BT_FUNC("(alt)", insn); + BT_INSN(insn, "(alt)"); return ret; } } @@ -3888,10 +3841,8 @@ static int validate_unret(struct objtool_file *file, struct instruction *insn) } ret = validate_unret(file, insn->jump_dest); if (ret) { - if (opts.backtrace) { - BT_FUNC("(branch%s)", insn, - insn->type == INSN_JUMP_CONDITIONAL ? "-cond" : ""); - } + BT_INSN(insn, "(branch%s)", + insn->type == INSN_JUMP_CONDITIONAL ? "-cond" : ""); return ret; } @@ -3913,8 +3864,7 @@ static int validate_unret(struct objtool_file *file, struct instruction *insn) ret = validate_unret(file, dest); if (ret) { - if (opts.backtrace) - BT_FUNC("(call)", insn); + BT_INSN(insn, "(call)"); return ret; } /* @@ -3943,7 +3893,7 @@ static int validate_unret(struct objtool_file *file, struct instruction *insn) insn = next; } - return warnings; + return 0; } /* @@ -4178,7 +4128,6 @@ static int add_prefix_symbols(struct objtool_file *file) { struct section *sec; struct symbol *func; - int warnings = 0; for_each_sec(file, sec) { if (!(sec->sh.sh_flags & SHF_EXECINSTR)) @@ -4192,7 +4141,7 @@ static int add_prefix_symbols(struct objtool_file *file) } } - return warnings; + return 0; } static int validate_symbol(struct objtool_file *file, struct section *sec, @@ -4216,8 +4165,8 @@ static int validate_symbol(struct objtool_file *file, struct section *sec, state->uaccess = sym->uaccess_safe; ret = validate_branch(file, insn_func(insn), insn, *state); - if (ret && opts.backtrace) - BT_FUNC("<=== (sym)", insn); + if (ret) + BT_INSN(insn, "<=== (sym)"); return ret; } @@ -4333,8 +4282,8 @@ static int validate_ibt_insn(struct objtool_file *file, struct instruction *insn for (reloc = insn_reloc(file, insn); reloc; reloc = find_reloc_by_dest_range(file->elf, insn->sec, - reloc->offset + 1, - (insn->offset + insn->len) - (reloc->offset + 1))) { + reloc_offset(reloc) + 1, + (insn->offset + insn->len) - (reloc_offset(reloc) + 1))) { /* * static_call_update() references the trampoline, which @@ -4344,10 +4293,11 @@ static int validate_ibt_insn(struct objtool_file *file, struct instruction *insn continue; off = reloc->sym->offset; - if (reloc->type == R_X86_64_PC32 || reloc->type == R_X86_64_PLT32) - off += arch_dest_reloc_offset(reloc->addend); + if (reloc_type(reloc) == R_X86_64_PC32 || + reloc_type(reloc) == R_X86_64_PLT32) + off += arch_dest_reloc_offset(reloc_addend(reloc)); else - off += reloc->addend; + off += reloc_addend(reloc); dest = find_insn(file, reloc->sym->sec, off); if (!dest) @@ -4404,7 +4354,7 @@ static int validate_ibt_data_reloc(struct objtool_file *file, struct instruction *dest; dest = find_insn(file, reloc->sym->sec, - reloc->sym->offset + reloc->addend); + reloc->sym->offset + reloc_addend(reloc)); if (!dest) return 0; @@ -4417,7 +4367,7 @@ static int validate_ibt_data_reloc(struct objtool_file *file, return 0; WARN_FUNC("data relocation to !ENDBR: %s", - reloc->sec->base, reloc->offset, + reloc->sec->base, reloc_offset(reloc), offstr(dest->sec, dest->offset)); return 1; @@ -4444,7 +4394,7 @@ static int validate_ibt(struct objtool_file *file) if (sec->sh.sh_flags & SHF_EXECINSTR) continue; - if (!sec->reloc) + if (!sec->rsec) continue; /* @@ -4471,7 +4421,7 @@ static int validate_ibt(struct objtool_file *file) strstr(sec->name, "__patchable_function_entries")) continue; - list_for_each_entry(reloc, &sec->reloc->reloc_list, list) + for_each_reloc(sec->rsec, reloc) warnings += validate_ibt_data_reloc(file, reloc); } @@ -4511,9 +4461,40 @@ static int validate_sls(struct objtool_file *file) return warnings; } +static bool ignore_noreturn_call(struct instruction *insn) +{ + struct symbol *call_dest = insn_call_dest(insn); + + /* + * FIXME: hack, we need a real noreturn solution + * + * Problem is, exc_double_fault() may or may not return, depending on + * whether CONFIG_X86_ESPFIX64 is set. But objtool has no visibility + * to the kernel config. + * + * Other potential ways to fix it: + * + * - have compiler communicate __noreturn functions somehow + * - remove CONFIG_X86_ESPFIX64 + * - read the .config file + * - add a cmdline option + * - create a generic objtool annotation format (vs a bunch of custom + * formats) and annotate it + */ + if (!strcmp(call_dest->name, "exc_double_fault")) { + /* prevent further unreachable warnings for the caller */ + insn->sym->warned = 1; + return true; + } + + return false; +} + static int validate_reachable_instructions(struct objtool_file *file) { - struct instruction *insn; + struct instruction *insn, *prev_insn; + struct symbol *call_dest; + int warnings = 0; if (file->ignore_unreachables) return 0; @@ -4522,13 +4503,127 @@ static int validate_reachable_instructions(struct objtool_file *file) if (insn->visited || ignore_unreachable_insn(file, insn)) continue; + prev_insn = prev_insn_same_sec(file, insn); + if (prev_insn && prev_insn->dead_end) { + call_dest = insn_call_dest(prev_insn); + if (call_dest && !ignore_noreturn_call(prev_insn)) { + WARN_INSN(insn, "%s() is missing a __noreturn annotation", + call_dest->name); + warnings++; + continue; + } + } + WARN_INSN(insn, "unreachable instruction"); - return 1; + warnings++; + } + + return warnings; +} + +/* 'funcs' is a space-separated list of function names */ +static int disas_funcs(const char *funcs) +{ + const char *objdump_str, *cross_compile; + int size, ret; + char *cmd; + + cross_compile = getenv("CROSS_COMPILE"); + + objdump_str = "%sobjdump -wdr %s | gawk -M -v _funcs='%s' '" + "BEGIN { split(_funcs, funcs); }" + "/^$/ { func_match = 0; }" + "/<.*>:/ { " + "f = gensub(/.*<(.*)>:/, \"\\\\1\", 1);" + "for (i in funcs) {" + "if (funcs[i] == f) {" + "func_match = 1;" + "base = strtonum(\"0x\" $1);" + "break;" + "}" + "}" + "}" + "{" + "if (func_match) {" + "addr = strtonum(\"0x\" $1);" + "printf(\"%%04x \", addr - base);" + "print;" + "}" + "}' 1>&2"; + + /* fake snprintf() to calculate the size */ + size = snprintf(NULL, 0, objdump_str, cross_compile, objname, funcs) + 1; + if (size <= 0) { + WARN("objdump string size calculation failed"); + return -1; + } + + cmd = malloc(size); + + /* real snprintf() */ + snprintf(cmd, size, objdump_str, cross_compile, objname, funcs); + ret = system(cmd); + if (ret) { + WARN("disassembly failed: %d", ret); + return -1; } return 0; } +static int disas_warned_funcs(struct objtool_file *file) +{ + struct symbol *sym; + char *funcs = NULL, *tmp; + + for_each_sym(file, sym) { + if (sym->warned) { + if (!funcs) { + funcs = malloc(strlen(sym->name) + 1); + strcpy(funcs, sym->name); + } else { + tmp = malloc(strlen(funcs) + strlen(sym->name) + 2); + sprintf(tmp, "%s %s", funcs, sym->name); + free(funcs); + funcs = tmp; + } + } + } + + if (funcs) + disas_funcs(funcs); + + return 0; +} + +struct insn_chunk { + void *addr; + struct insn_chunk *next; +}; + +/* + * Reduce peak RSS usage by freeing insns memory before writing the ELF file, + * which can trigger more allocations for .debug_* sections whose data hasn't + * been read yet. + */ +static void free_insns(struct objtool_file *file) +{ + struct instruction *insn; + struct insn_chunk *chunks = NULL, *chunk; + + for_each_insn(file, insn) { + if (!insn->idx) { + chunk = malloc(sizeof(*chunk)); + chunk->addr = insn; + chunk->next = chunks; + chunks = chunk; + } + } + + for (chunk = chunks; chunk; chunk = chunk->next) + free(chunk->addr); +} + int check(struct objtool_file *file) { int ret, warnings = 0; @@ -4537,6 +4632,8 @@ int check(struct objtool_file *file) init_cfi_state(&init_cfi); init_cfi_state(&func_cfi); set_func_state(&func_cfi); + init_cfi_state(&force_undefined_cfi); + force_undefined_cfi.force_undefined = true; if (!cfi_hash_alloc(1UL << (file->elf->symbol_bits - 3))) goto out; @@ -4673,6 +4770,10 @@ int check(struct objtool_file *file) warnings += ret; } + free_insns(file); + + if (opts.verbose) + disas_warned_funcs(file); if (opts.stats) { printf("nr_insns_visited: %ld\n", nr_insns_visited); diff --git a/tools/objtool/elf.c b/tools/objtool/elf.c index 500e92979a31..d420b5d2e2b6 100644 --- a/tools/objtool/elf.c +++ b/tools/objtool/elf.c @@ -32,16 +32,52 @@ static inline u32 str_hash(const char *str) #define __elf_table(name) (elf->name##_hash) #define __elf_bits(name) (elf->name##_bits) -#define elf_hash_add(name, node, key) \ - hlist_add_head(node, &__elf_table(name)[hash_min(key, __elf_bits(name))]) +#define __elf_table_entry(name, key) \ + __elf_table(name)[hash_min(key, __elf_bits(name))] + +#define elf_hash_add(name, node, key) \ +({ \ + struct elf_hash_node *__node = node; \ + __node->next = __elf_table_entry(name, key); \ + __elf_table_entry(name, key) = __node; \ +}) + +static inline void __elf_hash_del(struct elf_hash_node *node, + struct elf_hash_node **head) +{ + struct elf_hash_node *cur, *prev; + + if (node == *head) { + *head = node->next; + return; + } + + for (prev = NULL, cur = *head; cur; prev = cur, cur = cur->next) { + if (cur == node) { + prev->next = cur->next; + break; + } + } +} -#define elf_hash_for_each_possible(name, obj, member, key) \ - hlist_for_each_entry(obj, &__elf_table(name)[hash_min(key, __elf_bits(name))], member) +#define elf_hash_del(name, node, key) \ + __elf_hash_del(node, &__elf_table_entry(name, key)) + +#define elf_list_entry(ptr, type, member) \ +({ \ + typeof(ptr) __ptr = (ptr); \ + __ptr ? container_of(__ptr, type, member) : NULL; \ +}) + +#define elf_hash_for_each_possible(name, obj, member, key) \ + for (obj = elf_list_entry(__elf_table_entry(name, key), typeof(*obj), member); \ + obj; \ + obj = elf_list_entry(obj->member.next, typeof(*(obj)), member)) #define elf_alloc_hash(name, size) \ ({ \ __elf_bits(name) = max(10, ilog2(size)); \ - __elf_table(name) = mmap(NULL, sizeof(struct hlist_head) << __elf_bits(name), \ + __elf_table(name) = mmap(NULL, sizeof(struct elf_hash_node *) << __elf_bits(name), \ PROT_READ|PROT_WRITE, \ MAP_PRIVATE|MAP_ANON, -1, 0); \ if (__elf_table(name) == (void *)-1L) { \ @@ -233,21 +269,22 @@ struct reloc *find_reloc_by_dest_range(const struct elf *elf, struct section *se unsigned long offset, unsigned int len) { struct reloc *reloc, *r = NULL; + struct section *rsec; unsigned long o; - if (!sec->reloc) + rsec = sec->rsec; + if (!rsec) return NULL; - sec = sec->reloc; - for_offset_range(o, offset, offset + len) { elf_hash_for_each_possible(reloc, reloc, hash, - sec_offset_hash(sec, o)) { - if (reloc->sec != sec) + sec_offset_hash(rsec, o)) { + if (reloc->sec != rsec) continue; - if (reloc->offset >= offset && reloc->offset < offset + len) { - if (!r || reloc->offset < r->offset) + if (reloc_offset(reloc) >= offset && + reloc_offset(reloc) < offset + len) { + if (!r || reloc_offset(reloc) < reloc_offset(r)) r = reloc; } } @@ -263,6 +300,11 @@ struct reloc *find_reloc_by_dest(const struct elf *elf, struct section *sec, uns return find_reloc_by_dest_range(elf, sec, offset, 1); } +static bool is_dwarf_section(struct section *sec) +{ + return !strncmp(sec->name, ".debug_", 7); +} + static int read_sections(struct elf *elf) { Elf_Scn *s = NULL; @@ -293,7 +335,6 @@ static int read_sections(struct elf *elf) sec = &elf->section_data[i]; INIT_LIST_HEAD(&sec->symbol_list); - INIT_LIST_HEAD(&sec->reloc_list); s = elf_getscn(elf->elf, i); if (!s) { @@ -314,7 +355,7 @@ static int read_sections(struct elf *elf) return -1; } - if (sec->sh.sh_size != 0) { + if (sec->sh.sh_size != 0 && !is_dwarf_section(sec)) { sec->data = elf_getdata(s, NULL); if (!sec->data) { WARN_ELF("elf_getdata"); @@ -328,12 +369,12 @@ static int read_sections(struct elf *elf) } } - if (sec->sh.sh_flags & SHF_EXECINSTR) - elf->text_size += sec->sh.sh_size; - list_add_tail(&sec->list, &elf->sections); elf_hash_add(section, &sec->hash, sec->idx); elf_hash_add(section_name, &sec->name_hash, str_hash(sec->name)); + + if (is_reloc_sec(sec)) + elf->num_relocs += sec_num_entries(sec); } if (opts.stats) { @@ -356,7 +397,6 @@ static void elf_add_symbol(struct elf *elf, struct symbol *sym) struct rb_node *pnode; struct symbol *iter; - INIT_LIST_HEAD(&sym->reloc_list); INIT_LIST_HEAD(&sym->pv_target); sym->alias = sym; @@ -407,7 +447,7 @@ static int read_symbols(struct elf *elf) if (symtab_shndx) shndx_data = symtab_shndx->data; - symbols_nr = symtab->sh.sh_size / symtab->sh.sh_entsize; + symbols_nr = sec_num_entries(symtab); } else { /* * A missing symbol table is actually possible if it's an empty @@ -533,52 +573,17 @@ err: return -1; } -static struct section *elf_create_reloc_section(struct elf *elf, - struct section *base, - int reltype); - -int elf_add_reloc(struct elf *elf, struct section *sec, unsigned long offset, - unsigned int type, struct symbol *sym, s64 addend) -{ - struct reloc *reloc; - - if (!sec->reloc && !elf_create_reloc_section(elf, sec, SHT_RELA)) - return -1; - - reloc = malloc(sizeof(*reloc)); - if (!reloc) { - perror("malloc"); - return -1; - } - memset(reloc, 0, sizeof(*reloc)); - - reloc->sec = sec->reloc; - reloc->offset = offset; - reloc->type = type; - reloc->sym = sym; - reloc->addend = addend; - - list_add_tail(&reloc->sym_reloc_entry, &sym->reloc_list); - list_add_tail(&reloc->list, &sec->reloc->reloc_list); - elf_hash_add(reloc, &reloc->hash, reloc_hash(reloc)); - - sec->reloc->sh.sh_size += sec->reloc->sh.sh_entsize; - sec->reloc->changed = true; - - return 0; -} - /* - * Ensure that any reloc section containing references to @sym is marked - * changed such that it will get re-generated in elf_rebuild_reloc_sections() - * with the new symbol index. + * @sym's idx has changed. Update the relocs which reference it. */ -static void elf_dirty_reloc_sym(struct elf *elf, struct symbol *sym) +static int elf_update_sym_relocs(struct elf *elf, struct symbol *sym) { struct reloc *reloc; - list_for_each_entry(reloc, &sym->reloc_list, sym_reloc_entry) - reloc->sec->changed = true; + for (reloc = sym->relocs; reloc; reloc = reloc->sym_next_reloc) + set_reloc_sym(elf, reloc, reloc->sym->idx); + + return 0; } /* @@ -655,7 +660,7 @@ static int elf_update_symbol(struct elf *elf, struct section *symtab, symtab_data->d_align = 1; symtab_data->d_type = ELF_T_SYM; - symtab->changed = true; + mark_sec_changed(elf, symtab, true); symtab->truncate = true; if (t) { @@ -670,7 +675,7 @@ static int elf_update_symbol(struct elf *elf, struct section *symtab, shndx_data->d_align = sizeof(Elf32_Word); shndx_data->d_type = ELF_T_WORD; - symtab_shndx->changed = true; + mark_sec_changed(elf, symtab_shndx, true); symtab_shndx->truncate = true; } @@ -734,7 +739,7 @@ __elf_create_symbol(struct elf *elf, struct symbol *sym) return NULL; } - new_idx = symtab->sh.sh_size / symtab->sh.sh_entsize; + new_idx = sec_num_entries(symtab); if (GELF_ST_BIND(sym->sym.st_info) != STB_LOCAL) goto non_local; @@ -746,18 +751,19 @@ __elf_create_symbol(struct elf *elf, struct symbol *sym) first_non_local = symtab->sh.sh_info; old = find_symbol_by_index(elf, first_non_local); if (old) { - old->idx = new_idx; - hlist_del(&old->hash); - elf_hash_add(symbol, &old->hash, old->idx); - - elf_dirty_reloc_sym(elf, old); + elf_hash_del(symbol, &old->hash, old->idx); + elf_hash_add(symbol, &old->hash, new_idx); + old->idx = new_idx; if (elf_update_symbol(elf, symtab, symtab_shndx, old)) { WARN("elf_update_symbol move"); return NULL; } + if (elf_update_sym_relocs(elf, old)) + return NULL; + new_idx = first_non_local; } @@ -774,11 +780,11 @@ non_local: } symtab->sh.sh_size += symtab->sh.sh_entsize; - symtab->changed = true; + mark_sec_changed(elf, symtab, true); if (symtab_shndx) { symtab_shndx->sh.sh_size += sizeof(Elf32_Word); - symtab_shndx->changed = true; + mark_sec_changed(elf, symtab_shndx, true); } return sym; @@ -841,13 +847,57 @@ elf_create_prefix_symbol(struct elf *elf, struct symbol *orig, long size) return sym; } -int elf_add_reloc_to_insn(struct elf *elf, struct section *sec, - unsigned long offset, unsigned int type, - struct section *insn_sec, unsigned long insn_off) +static struct reloc *elf_init_reloc(struct elf *elf, struct section *rsec, + unsigned int reloc_idx, + unsigned long offset, struct symbol *sym, + s64 addend, unsigned int type) +{ + struct reloc *reloc, empty = { 0 }; + + if (reloc_idx >= sec_num_entries(rsec)) { + WARN("%s: bad reloc_idx %u for %s with %d relocs", + __func__, reloc_idx, rsec->name, sec_num_entries(rsec)); + return NULL; + } + + reloc = &rsec->relocs[reloc_idx]; + + if (memcmp(reloc, &empty, sizeof(empty))) { + WARN("%s: %s: reloc %d already initialized!", + __func__, rsec->name, reloc_idx); + return NULL; + } + + reloc->sec = rsec; + reloc->sym = sym; + + set_reloc_offset(elf, reloc, offset); + set_reloc_sym(elf, reloc, sym->idx); + set_reloc_type(elf, reloc, type); + set_reloc_addend(elf, reloc, addend); + + elf_hash_add(reloc, &reloc->hash, reloc_hash(reloc)); + reloc->sym_next_reloc = sym->relocs; + sym->relocs = reloc; + + return reloc; +} + +struct reloc *elf_init_reloc_text_sym(struct elf *elf, struct section *sec, + unsigned long offset, + unsigned int reloc_idx, + struct section *insn_sec, + unsigned long insn_off) { struct symbol *sym = insn_sec->sym; int addend = insn_off; + if (!(insn_sec->sh.sh_flags & SHF_EXECINSTR)) { + WARN("bad call to %s() for data symbol %s", + __func__, sym->name); + return NULL; + } + if (!sym) { /* * Due to how weak functions work, we must use section based @@ -857,108 +907,86 @@ int elf_add_reloc_to_insn(struct elf *elf, struct section *sec, */ sym = elf_create_section_symbol(elf, insn_sec); if (!sym) - return -1; + return NULL; insn_sec->sym = sym; } - return elf_add_reloc(elf, sec, offset, type, sym, addend); + return elf_init_reloc(elf, sec->rsec, reloc_idx, offset, sym, addend, + elf_text_rela_type(elf)); } -static int read_rel_reloc(struct section *sec, int i, struct reloc *reloc, unsigned int *symndx) +struct reloc *elf_init_reloc_data_sym(struct elf *elf, struct section *sec, + unsigned long offset, + unsigned int reloc_idx, + struct symbol *sym, + s64 addend) { - if (!gelf_getrel(sec->data, i, &reloc->rel)) { - WARN_ELF("gelf_getrel"); - return -1; + if (sym->sec && (sec->sh.sh_flags & SHF_EXECINSTR)) { + WARN("bad call to %s() for text symbol %s", + __func__, sym->name); + return NULL; } - reloc->type = GELF_R_TYPE(reloc->rel.r_info); - reloc->addend = 0; - reloc->offset = reloc->rel.r_offset; - *symndx = GELF_R_SYM(reloc->rel.r_info); - return 0; -} -static int read_rela_reloc(struct section *sec, int i, struct reloc *reloc, unsigned int *symndx) -{ - if (!gelf_getrela(sec->data, i, &reloc->rela)) { - WARN_ELF("gelf_getrela"); - return -1; - } - reloc->type = GELF_R_TYPE(reloc->rela.r_info); - reloc->addend = reloc->rela.r_addend; - reloc->offset = reloc->rela.r_offset; - *symndx = GELF_R_SYM(reloc->rela.r_info); - return 0; + return elf_init_reloc(elf, sec->rsec, reloc_idx, offset, sym, addend, + elf_data_rela_type(elf)); } static int read_relocs(struct elf *elf) { - unsigned long nr_reloc, max_reloc = 0, tot_reloc = 0; - struct section *sec; + unsigned long nr_reloc, max_reloc = 0; + struct section *rsec; struct reloc *reloc; unsigned int symndx; struct symbol *sym; int i; - if (!elf_alloc_hash(reloc, elf->text_size / 16)) + if (!elf_alloc_hash(reloc, elf->num_relocs)) return -1; - list_for_each_entry(sec, &elf->sections, list) { - if ((sec->sh.sh_type != SHT_RELA) && - (sec->sh.sh_type != SHT_REL)) + list_for_each_entry(rsec, &elf->sections, list) { + if (!is_reloc_sec(rsec)) continue; - sec->base = find_section_by_index(elf, sec->sh.sh_info); - if (!sec->base) { + rsec->base = find_section_by_index(elf, rsec->sh.sh_info); + if (!rsec->base) { WARN("can't find base section for reloc section %s", - sec->name); + rsec->name); return -1; } - sec->base->reloc = sec; + rsec->base->rsec = rsec; nr_reloc = 0; - sec->reloc_data = calloc(sec->sh.sh_size / sec->sh.sh_entsize, sizeof(*reloc)); - if (!sec->reloc_data) { + rsec->relocs = calloc(sec_num_entries(rsec), sizeof(*reloc)); + if (!rsec->relocs) { perror("calloc"); return -1; } - for (i = 0; i < sec->sh.sh_size / sec->sh.sh_entsize; i++) { - reloc = &sec->reloc_data[i]; - switch (sec->sh.sh_type) { - case SHT_REL: - if (read_rel_reloc(sec, i, reloc, &symndx)) - return -1; - break; - case SHT_RELA: - if (read_rela_reloc(sec, i, reloc, &symndx)) - return -1; - break; - default: return -1; - } + for (i = 0; i < sec_num_entries(rsec); i++) { + reloc = &rsec->relocs[i]; - reloc->sec = sec; - reloc->idx = i; + reloc->sec = rsec; + symndx = reloc_sym(reloc); reloc->sym = sym = find_symbol_by_index(elf, symndx); if (!reloc->sym) { WARN("can't find reloc entry symbol %d for %s", - symndx, sec->name); + symndx, rsec->name); return -1; } - list_add_tail(&reloc->sym_reloc_entry, &sym->reloc_list); - list_add_tail(&reloc->list, &sec->reloc_list); elf_hash_add(reloc, &reloc->hash, reloc_hash(reloc)); + reloc->sym_next_reloc = sym->relocs; + sym->relocs = reloc; nr_reloc++; } max_reloc = max(max_reloc, nr_reloc); - tot_reloc += nr_reloc; } if (opts.stats) { printf("max_reloc: %lu\n", max_reloc); - printf("tot_reloc: %lu\n", tot_reloc); + printf("num_relocs: %lu\n", elf->num_relocs); printf("reloc_bits: %d\n", elf->reloc_bits); } @@ -1053,13 +1081,14 @@ static int elf_add_string(struct elf *elf, struct section *strtab, char *str) len = strtab->sh.sh_size; strtab->sh.sh_size += data->d_size; - strtab->changed = true; + + mark_sec_changed(elf, strtab, true); return len; } struct section *elf_create_section(struct elf *elf, const char *name, - unsigned int sh_flags, size_t entsize, int nr) + size_t entsize, unsigned int nr) { struct section *sec, *shstrtab; size_t size = entsize * nr; @@ -1073,7 +1102,6 @@ struct section *elf_create_section(struct elf *elf, const char *name, memset(sec, 0, sizeof(*sec)); INIT_LIST_HEAD(&sec->symbol_list); - INIT_LIST_HEAD(&sec->reloc_list); s = elf_newscn(elf->elf); if (!s) { @@ -1088,7 +1116,6 @@ struct section *elf_create_section(struct elf *elf, const char *name, } sec->idx = elf_ndxscn(s); - sec->changed = true; sec->data = elf_newdata(s); if (!sec->data) { @@ -1117,7 +1144,7 @@ struct section *elf_create_section(struct elf *elf, const char *name, sec->sh.sh_entsize = entsize; sec->sh.sh_type = SHT_PROGBITS; sec->sh.sh_addralign = 1; - sec->sh.sh_flags = SHF_ALLOC | sh_flags; + sec->sh.sh_flags = SHF_ALLOC; /* Add section name to .shstrtab (or .strtab for Clang) */ shstrtab = find_section_by_name(elf, ".shstrtab"); @@ -1135,158 +1162,66 @@ struct section *elf_create_section(struct elf *elf, const char *name, elf_hash_add(section, &sec->hash, sec->idx); elf_hash_add(section_name, &sec->name_hash, str_hash(sec->name)); - elf->changed = true; + mark_sec_changed(elf, sec, true); return sec; } -static struct section *elf_create_rel_reloc_section(struct elf *elf, struct section *base) +static struct section *elf_create_rela_section(struct elf *elf, + struct section *sec, + unsigned int reloc_nr) { - char *relocname; - struct section *sec; + struct section *rsec; + char *rsec_name; - relocname = malloc(strlen(base->name) + strlen(".rel") + 1); - if (!relocname) { + rsec_name = malloc(strlen(sec->name) + strlen(".rela") + 1); + if (!rsec_name) { perror("malloc"); return NULL; } - strcpy(relocname, ".rel"); - strcat(relocname, base->name); + strcpy(rsec_name, ".rela"); + strcat(rsec_name, sec->name); - sec = elf_create_section(elf, relocname, 0, sizeof(GElf_Rel), 0); - free(relocname); - if (!sec) + rsec = elf_create_section(elf, rsec_name, elf_rela_size(elf), reloc_nr); + free(rsec_name); + if (!rsec) return NULL; - base->reloc = sec; - sec->base = base; + rsec->data->d_type = ELF_T_RELA; + rsec->sh.sh_type = SHT_RELA; + rsec->sh.sh_addralign = elf_addr_size(elf); + rsec->sh.sh_link = find_section_by_name(elf, ".symtab")->idx; + rsec->sh.sh_info = sec->idx; + rsec->sh.sh_flags = SHF_INFO_LINK; + + rsec->relocs = calloc(sec_num_entries(rsec), sizeof(struct reloc)); + if (!rsec->relocs) { + perror("calloc"); + return NULL; + } - sec->sh.sh_type = SHT_REL; - sec->sh.sh_addralign = 8; - sec->sh.sh_link = find_section_by_name(elf, ".symtab")->idx; - sec->sh.sh_info = base->idx; - sec->sh.sh_flags = SHF_INFO_LINK; + sec->rsec = rsec; + rsec->base = sec; - return sec; + return rsec; } -static struct section *elf_create_rela_reloc_section(struct elf *elf, struct section *base) +struct section *elf_create_section_pair(struct elf *elf, const char *name, + size_t entsize, unsigned int nr, + unsigned int reloc_nr) { - char *relocname; struct section *sec; - int addrsize = elf_class_addrsize(elf); - - relocname = malloc(strlen(base->name) + strlen(".rela") + 1); - if (!relocname) { - perror("malloc"); - return NULL; - } - strcpy(relocname, ".rela"); - strcat(relocname, base->name); - if (addrsize == sizeof(u32)) - sec = elf_create_section(elf, relocname, 0, sizeof(Elf32_Rela), 0); - else - sec = elf_create_section(elf, relocname, 0, sizeof(GElf_Rela), 0); - free(relocname); + sec = elf_create_section(elf, name, entsize, nr); if (!sec) return NULL; - base->reloc = sec; - sec->base = base; - - sec->sh.sh_type = SHT_RELA; - sec->sh.sh_addralign = addrsize; - sec->sh.sh_link = find_section_by_name(elf, ".symtab")->idx; - sec->sh.sh_info = base->idx; - sec->sh.sh_flags = SHF_INFO_LINK; + if (!elf_create_rela_section(elf, sec, reloc_nr)) + return NULL; return sec; } -static struct section *elf_create_reloc_section(struct elf *elf, - struct section *base, - int reltype) -{ - switch (reltype) { - case SHT_REL: return elf_create_rel_reloc_section(elf, base); - case SHT_RELA: return elf_create_rela_reloc_section(elf, base); - default: return NULL; - } -} - -static int elf_rebuild_rel_reloc_section(struct section *sec) -{ - struct reloc *reloc; - int idx = 0; - void *buf; - - /* Allocate a buffer for relocations */ - buf = malloc(sec->sh.sh_size); - if (!buf) { - perror("malloc"); - return -1; - } - - sec->data->d_buf = buf; - sec->data->d_size = sec->sh.sh_size; - sec->data->d_type = ELF_T_REL; - - idx = 0; - list_for_each_entry(reloc, &sec->reloc_list, list) { - reloc->rel.r_offset = reloc->offset; - reloc->rel.r_info = GELF_R_INFO(reloc->sym->idx, reloc->type); - if (!gelf_update_rel(sec->data, idx, &reloc->rel)) { - WARN_ELF("gelf_update_rel"); - return -1; - } - idx++; - } - - return 0; -} - -static int elf_rebuild_rela_reloc_section(struct section *sec) -{ - struct reloc *reloc; - int idx = 0; - void *buf; - - /* Allocate a buffer for relocations with addends */ - buf = malloc(sec->sh.sh_size); - if (!buf) { - perror("malloc"); - return -1; - } - - sec->data->d_buf = buf; - sec->data->d_size = sec->sh.sh_size; - sec->data->d_type = ELF_T_RELA; - - idx = 0; - list_for_each_entry(reloc, &sec->reloc_list, list) { - reloc->rela.r_offset = reloc->offset; - reloc->rela.r_addend = reloc->addend; - reloc->rela.r_info = GELF_R_INFO(reloc->sym->idx, reloc->type); - if (!gelf_update_rela(sec->data, idx, &reloc->rela)) { - WARN_ELF("gelf_update_rela"); - return -1; - } - idx++; - } - - return 0; -} - -static int elf_rebuild_reloc_section(struct elf *elf, struct section *sec) -{ - switch (sec->sh.sh_type) { - case SHT_REL: return elf_rebuild_rel_reloc_section(sec); - case SHT_RELA: return elf_rebuild_rela_reloc_section(sec); - default: return -1; - } -} - int elf_write_insn(struct elf *elf, struct section *sec, unsigned long offset, unsigned int len, const char *insn) @@ -1299,37 +1234,8 @@ int elf_write_insn(struct elf *elf, struct section *sec, } memcpy(data->d_buf + offset, insn, len); - elf_flagdata(data, ELF_C_SET, ELF_F_DIRTY); - elf->changed = true; - - return 0; -} - -int elf_write_reloc(struct elf *elf, struct reloc *reloc) -{ - struct section *sec = reloc->sec; - - if (sec->sh.sh_type == SHT_REL) { - reloc->rel.r_info = GELF_R_INFO(reloc->sym->idx, reloc->type); - reloc->rel.r_offset = reloc->offset; - - if (!gelf_update_rel(sec->data, reloc->idx, &reloc->rel)) { - WARN_ELF("gelf_update_rel"); - return -1; - } - } else { - reloc->rela.r_info = GELF_R_INFO(reloc->sym->idx, reloc->type); - reloc->rela.r_addend = reloc->addend; - reloc->rela.r_offset = reloc->offset; - - if (!gelf_update_rela(sec->data, reloc->idx, &reloc->rela)) { - WARN_ELF("gelf_update_rela"); - return -1; - } - } - - elf->changed = true; + mark_sec_changed(elf, sec, true); return 0; } @@ -1401,25 +1307,20 @@ int elf_write(struct elf *elf) if (sec->truncate) elf_truncate_section(elf, sec); - if (sec->changed) { + if (sec_changed(sec)) { s = elf_getscn(elf->elf, sec->idx); if (!s) { WARN_ELF("elf_getscn"); return -1; } + + /* Note this also flags the section dirty */ if (!gelf_update_shdr(s, &sec->sh)) { WARN_ELF("gelf_update_shdr"); return -1; } - if (sec->base && - elf_rebuild_reloc_section(elf, sec)) { - WARN("elf_rebuild_reloc_section"); - return -1; - } - - sec->changed = false; - elf->changed = true; + mark_sec_changed(elf, sec, false); } } @@ -1439,30 +1340,14 @@ int elf_write(struct elf *elf) void elf_close(struct elf *elf) { - struct section *sec, *tmpsec; - struct symbol *sym, *tmpsym; - struct reloc *reloc, *tmpreloc; - if (elf->elf) elf_end(elf->elf); if (elf->fd > 0) close(elf->fd); - list_for_each_entry_safe(sec, tmpsec, &elf->sections, list) { - list_for_each_entry_safe(sym, tmpsym, &sec->symbol_list, list) { - list_del(&sym->list); - hash_del(&sym->hash); - } - list_for_each_entry_safe(reloc, tmpreloc, &sec->reloc_list, list) { - list_del(&reloc->list); - hash_del(&reloc->hash); - } - list_del(&sec->list); - free(sec->reloc_data); - } - - free(elf->symbol_data); - free(elf->section_data); - free(elf); + /* + * NOTE: All remaining allocations are leaked on purpose. Objtool is + * about to exit anyway. + */ } diff --git a/tools/objtool/include/objtool/builtin.h b/tools/objtool/include/objtool/builtin.h index 2a108e648b7a..fcca6662c8b4 100644 --- a/tools/objtool/include/objtool/builtin.h +++ b/tools/objtool/include/objtool/builtin.h @@ -37,6 +37,7 @@ struct opts { bool no_unreachable; bool sec_address; bool stats; + bool verbose; }; extern struct opts opts; diff --git a/tools/objtool/include/objtool/cfi.h b/tools/objtool/include/objtool/cfi.h index b1258e79a1b7..c8a6bec4f6b9 100644 --- a/tools/objtool/include/objtool/cfi.h +++ b/tools/objtool/include/objtool/cfi.h @@ -36,6 +36,7 @@ struct cfi_state { bool drap; bool signal; bool end; + bool force_undefined; }; #endif /* _OBJTOOL_CFI_H */ diff --git a/tools/objtool/include/objtool/elf.h b/tools/objtool/include/objtool/elf.h index e1ca588eb69d..c532d70864dc 100644 --- a/tools/objtool/include/objtool/elf.h +++ b/tools/objtool/include/objtool/elf.h @@ -12,6 +12,7 @@ #include <linux/hashtable.h> #include <linux/rbtree.h> #include <linux/jhash.h> +#include <arch/elf.h> #ifdef LIBELF_USE_DEPRECATED # define elf_getshdrnum elf_getshnum @@ -25,28 +26,31 @@ #define ELF_C_READ_MMAP ELF_C_READ #endif +struct elf_hash_node { + struct elf_hash_node *next; +}; + struct section { struct list_head list; - struct hlist_node hash; - struct hlist_node name_hash; + struct elf_hash_node hash; + struct elf_hash_node name_hash; GElf_Shdr sh; struct rb_root_cached symbol_tree; struct list_head symbol_list; - struct list_head reloc_list; - struct section *base, *reloc; + struct section *base, *rsec; struct symbol *sym; Elf_Data *data; char *name; int idx; - bool changed, text, rodata, noinstr, init, truncate; - struct reloc *reloc_data; + bool _changed, text, rodata, noinstr, init, truncate; + struct reloc *relocs; }; struct symbol { struct list_head list; struct rb_node node; - struct hlist_node hash; - struct hlist_node name_hash; + struct elf_hash_node hash; + struct elf_hash_node name_hash; GElf_Sym sym; struct section *sec; char *name; @@ -61,37 +65,27 @@ struct symbol { u8 return_thunk : 1; u8 fentry : 1; u8 profiling_func : 1; + u8 warned : 1; struct list_head pv_target; - struct list_head reloc_list; + struct reloc *relocs; }; struct reloc { - struct list_head list; - struct hlist_node hash; - union { - GElf_Rela rela; - GElf_Rel rel; - }; + struct elf_hash_node hash; struct section *sec; struct symbol *sym; - struct list_head sym_reloc_entry; - unsigned long offset; - unsigned int type; - s64 addend; - int idx; - bool jump_table_start; + struct reloc *sym_next_reloc; }; -#define ELF_HASH_BITS 20 - struct elf { Elf *elf; GElf_Ehdr ehdr; int fd; bool changed; char *name; - unsigned int text_size, num_files; + unsigned int num_files; struct list_head sections; + unsigned long num_relocs; int symbol_bits; int symbol_name_bits; @@ -99,44 +93,54 @@ struct elf { int section_name_bits; int reloc_bits; - struct hlist_head *symbol_hash; - struct hlist_head *symbol_name_hash; - struct hlist_head *section_hash; - struct hlist_head *section_name_hash; - struct hlist_head *reloc_hash; + struct elf_hash_node **symbol_hash; + struct elf_hash_node **symbol_name_hash; + struct elf_hash_node **section_hash; + struct elf_hash_node **section_name_hash; + struct elf_hash_node **reloc_hash; struct section *section_data; struct symbol *symbol_data; }; -#define OFFSET_STRIDE_BITS 4 -#define OFFSET_STRIDE (1UL << OFFSET_STRIDE_BITS) -#define OFFSET_STRIDE_MASK (~(OFFSET_STRIDE - 1)) - -#define for_offset_range(_offset, _start, _end) \ - for (_offset = ((_start) & OFFSET_STRIDE_MASK); \ - _offset >= ((_start) & OFFSET_STRIDE_MASK) && \ - _offset <= ((_end) & OFFSET_STRIDE_MASK); \ - _offset += OFFSET_STRIDE) +struct elf *elf_open_read(const char *name, int flags); -static inline u32 sec_offset_hash(struct section *sec, unsigned long offset) -{ - u32 ol, oh, idx = sec->idx; +struct section *elf_create_section(struct elf *elf, const char *name, + size_t entsize, unsigned int nr); +struct section *elf_create_section_pair(struct elf *elf, const char *name, + size_t entsize, unsigned int nr, + unsigned int reloc_nr); - offset &= OFFSET_STRIDE_MASK; +struct symbol *elf_create_prefix_symbol(struct elf *elf, struct symbol *orig, long size); - ol = offset; - oh = (offset >> 16) >> 16; +struct reloc *elf_init_reloc_text_sym(struct elf *elf, struct section *sec, + unsigned long offset, + unsigned int reloc_idx, + struct section *insn_sec, + unsigned long insn_off); - __jhash_mix(ol, oh, idx); +struct reloc *elf_init_reloc_data_sym(struct elf *elf, struct section *sec, + unsigned long offset, + unsigned int reloc_idx, + struct symbol *sym, + s64 addend); - return ol; -} +int elf_write_insn(struct elf *elf, struct section *sec, + unsigned long offset, unsigned int len, + const char *insn); +int elf_write(struct elf *elf); +void elf_close(struct elf *elf); -static inline u32 reloc_hash(struct reloc *reloc) -{ - return sec_offset_hash(reloc->sec, reloc->offset); -} +struct section *find_section_by_name(const struct elf *elf, const char *name); +struct symbol *find_func_by_offset(struct section *sec, unsigned long offset); +struct symbol *find_symbol_by_offset(struct section *sec, unsigned long offset); +struct symbol *find_symbol_by_name(const struct elf *elf, const char *name); +struct symbol *find_symbol_containing(const struct section *sec, unsigned long offset); +int find_symbol_hole_containing(const struct section *sec, unsigned long offset); +struct reloc *find_reloc_by_dest(const struct elf *elf, struct section *sec, unsigned long offset); +struct reloc *find_reloc_by_dest_range(const struct elf *elf, struct section *sec, + unsigned long offset, unsigned int len); +struct symbol *find_func_containing(struct section *sec, unsigned long offset); /* * Try to see if it's a whole archive (vmlinux.o or module). @@ -148,42 +152,147 @@ static inline bool has_multiple_files(struct elf *elf) return elf->num_files > 1; } -static inline int elf_class_addrsize(struct elf *elf) +static inline size_t elf_addr_size(struct elf *elf) { - if (elf->ehdr.e_ident[EI_CLASS] == ELFCLASS32) - return sizeof(u32); - else - return sizeof(u64); + return elf->ehdr.e_ident[EI_CLASS] == ELFCLASS32 ? 4 : 8; } -struct elf *elf_open_read(const char *name, int flags); -struct section *elf_create_section(struct elf *elf, const char *name, unsigned int sh_flags, size_t entsize, int nr); +static inline size_t elf_rela_size(struct elf *elf) +{ + return elf_addr_size(elf) == 4 ? sizeof(Elf32_Rela) : sizeof(Elf64_Rela); +} -struct symbol *elf_create_prefix_symbol(struct elf *elf, struct symbol *orig, long size); +static inline unsigned int elf_data_rela_type(struct elf *elf) +{ + return elf_addr_size(elf) == 4 ? R_DATA32 : R_DATA64; +} -int elf_add_reloc(struct elf *elf, struct section *sec, unsigned long offset, - unsigned int type, struct symbol *sym, s64 addend); -int elf_add_reloc_to_insn(struct elf *elf, struct section *sec, - unsigned long offset, unsigned int type, - struct section *insn_sec, unsigned long insn_off); +static inline unsigned int elf_text_rela_type(struct elf *elf) +{ + return elf_addr_size(elf) == 4 ? R_TEXT32 : R_TEXT64; +} -int elf_write_insn(struct elf *elf, struct section *sec, - unsigned long offset, unsigned int len, - const char *insn); -int elf_write_reloc(struct elf *elf, struct reloc *reloc); -int elf_write(struct elf *elf); -void elf_close(struct elf *elf); +static inline bool is_reloc_sec(struct section *sec) +{ + return sec->sh.sh_type == SHT_RELA || sec->sh.sh_type == SHT_REL; +} -struct section *find_section_by_name(const struct elf *elf, const char *name); -struct symbol *find_func_by_offset(struct section *sec, unsigned long offset); -struct symbol *find_symbol_by_offset(struct section *sec, unsigned long offset); -struct symbol *find_symbol_by_name(const struct elf *elf, const char *name); -struct symbol *find_symbol_containing(const struct section *sec, unsigned long offset); -int find_symbol_hole_containing(const struct section *sec, unsigned long offset); -struct reloc *find_reloc_by_dest(const struct elf *elf, struct section *sec, unsigned long offset); -struct reloc *find_reloc_by_dest_range(const struct elf *elf, struct section *sec, - unsigned long offset, unsigned int len); -struct symbol *find_func_containing(struct section *sec, unsigned long offset); +static inline bool sec_changed(struct section *sec) +{ + return sec->_changed; +} + +static inline void mark_sec_changed(struct elf *elf, struct section *sec, + bool changed) +{ + sec->_changed = changed; + elf->changed |= changed; +} + +static inline unsigned int sec_num_entries(struct section *sec) +{ + return sec->sh.sh_size / sec->sh.sh_entsize; +} + +static inline unsigned int reloc_idx(struct reloc *reloc) +{ + return reloc - reloc->sec->relocs; +} + +static inline void *reloc_rel(struct reloc *reloc) +{ + struct section *rsec = reloc->sec; + + return rsec->data->d_buf + (reloc_idx(reloc) * rsec->sh.sh_entsize); +} + +static inline bool is_32bit_reloc(struct reloc *reloc) +{ + /* + * Elf32_Rel: 8 bytes + * Elf32_Rela: 12 bytes + * Elf64_Rel: 16 bytes + * Elf64_Rela: 24 bytes + */ + return reloc->sec->sh.sh_entsize < 16; +} + +#define __get_reloc_field(reloc, field) \ +({ \ + is_32bit_reloc(reloc) ? \ + ((Elf32_Rela *)reloc_rel(reloc))->field : \ + ((Elf64_Rela *)reloc_rel(reloc))->field; \ +}) + +#define __set_reloc_field(reloc, field, val) \ +({ \ + if (is_32bit_reloc(reloc)) \ + ((Elf32_Rela *)reloc_rel(reloc))->field = val; \ + else \ + ((Elf64_Rela *)reloc_rel(reloc))->field = val; \ +}) + +static inline u64 reloc_offset(struct reloc *reloc) +{ + return __get_reloc_field(reloc, r_offset); +} + +static inline void set_reloc_offset(struct elf *elf, struct reloc *reloc, u64 offset) +{ + __set_reloc_field(reloc, r_offset, offset); + mark_sec_changed(elf, reloc->sec, true); +} + +static inline s64 reloc_addend(struct reloc *reloc) +{ + return __get_reloc_field(reloc, r_addend); +} + +static inline void set_reloc_addend(struct elf *elf, struct reloc *reloc, s64 addend) +{ + __set_reloc_field(reloc, r_addend, addend); + mark_sec_changed(elf, reloc->sec, true); +} + + +static inline unsigned int reloc_sym(struct reloc *reloc) +{ + u64 info = __get_reloc_field(reloc, r_info); + + return is_32bit_reloc(reloc) ? + ELF32_R_SYM(info) : + ELF64_R_SYM(info); +} + +static inline unsigned int reloc_type(struct reloc *reloc) +{ + u64 info = __get_reloc_field(reloc, r_info); + + return is_32bit_reloc(reloc) ? + ELF32_R_TYPE(info) : + ELF64_R_TYPE(info); +} + +static inline void set_reloc_sym(struct elf *elf, struct reloc *reloc, unsigned int sym) +{ + u64 info = is_32bit_reloc(reloc) ? + ELF32_R_INFO(sym, reloc_type(reloc)) : + ELF64_R_INFO(sym, reloc_type(reloc)); + + __set_reloc_field(reloc, r_info, info); + + mark_sec_changed(elf, reloc->sec, true); +} +static inline void set_reloc_type(struct elf *elf, struct reloc *reloc, unsigned int type) +{ + u64 info = is_32bit_reloc(reloc) ? + ELF32_R_INFO(reloc_sym(reloc), type) : + ELF64_R_INFO(reloc_sym(reloc), type); + + __set_reloc_field(reloc, r_info, info); + + mark_sec_changed(elf, reloc->sec, true); +} #define for_each_sec(file, sec) \ list_for_each_entry(sec, &file->elf->sections, list) @@ -197,4 +306,44 @@ struct symbol *find_func_containing(struct section *sec, unsigned long offset); for_each_sec(file, __sec) \ sec_for_each_sym(__sec, sym) +#define for_each_reloc(rsec, reloc) \ + for (int __i = 0, __fake = 1; __fake; __fake = 0) \ + for (reloc = rsec->relocs; \ + __i < sec_num_entries(rsec); \ + __i++, reloc++) + +#define for_each_reloc_from(rsec, reloc) \ + for (int __i = reloc_idx(reloc); \ + __i < sec_num_entries(rsec); \ + __i++, reloc++) + +#define OFFSET_STRIDE_BITS 4 +#define OFFSET_STRIDE (1UL << OFFSET_STRIDE_BITS) +#define OFFSET_STRIDE_MASK (~(OFFSET_STRIDE - 1)) + +#define for_offset_range(_offset, _start, _end) \ + for (_offset = ((_start) & OFFSET_STRIDE_MASK); \ + _offset >= ((_start) & OFFSET_STRIDE_MASK) && \ + _offset <= ((_end) & OFFSET_STRIDE_MASK); \ + _offset += OFFSET_STRIDE) + +static inline u32 sec_offset_hash(struct section *sec, unsigned long offset) +{ + u32 ol, oh, idx = sec->idx; + + offset &= OFFSET_STRIDE_MASK; + + ol = offset; + oh = (offset >> 16) >> 16; + + __jhash_mix(ol, oh, idx); + + return ol; +} + +static inline u32 reloc_hash(struct reloc *reloc) +{ + return sec_offset_hash(reloc->sec, reloc_offset(reloc)); +} + #endif /* _OBJTOOL_ELF_H */ diff --git a/tools/objtool/include/objtool/warn.h b/tools/objtool/include/objtool/warn.h index b1c920dc9516..ac04d3fe4dd9 100644 --- a/tools/objtool/include/objtool/warn.h +++ b/tools/objtool/include/objtool/warn.h @@ -55,15 +55,22 @@ static inline char *offstr(struct section *sec, unsigned long offset) #define WARN_INSN(insn, format, ...) \ ({ \ - WARN_FUNC(format, insn->sec, insn->offset, ##__VA_ARGS__); \ + struct instruction *_insn = (insn); \ + if (!_insn->sym || !_insn->sym->warned) \ + WARN_FUNC(format, _insn->sec, _insn->offset, \ + ##__VA_ARGS__); \ + if (_insn->sym) \ + _insn->sym->warned = 1; \ }) -#define BT_FUNC(format, insn, ...) \ -({ \ - struct instruction *_insn = (insn); \ - char *_str = offstr(_insn->sec, _insn->offset); \ - WARN(" %s: " format, _str, ##__VA_ARGS__); \ - free(_str); \ +#define BT_INSN(insn, format, ...) \ +({ \ + if (opts.verbose || opts.backtrace) { \ + struct instruction *_insn = (insn); \ + char *_str = offstr(_insn->sec, _insn->offset); \ + WARN(" %s: " format, _str, ##__VA_ARGS__); \ + free(_str); \ + } \ }) #define WARN_ELF(format, ...) \ diff --git a/tools/objtool/noreturns.h b/tools/objtool/noreturns.h new file mode 100644 index 000000000000..1514e84d5cc4 --- /dev/null +++ b/tools/objtool/noreturns.h @@ -0,0 +1,46 @@ +/* SPDX-License-Identifier: GPL-2.0 */ + +/* + * This is a (sorted!) list of all known __noreturn functions in the kernel. + * It's needed for objtool to properly reverse-engineer the control flow graph. + * + * Yes, this is unfortunate. A better solution is in the works. + */ +NORETURN(__invalid_creds) +NORETURN(__kunit_abort) +NORETURN(__module_put_and_kthread_exit) +NORETURN(__reiserfs_panic) +NORETURN(__stack_chk_fail) +NORETURN(__ubsan_handle_builtin_unreachable) +NORETURN(arch_call_rest_init) +NORETURN(arch_cpu_idle_dead) +NORETURN(btrfs_assertfail) +NORETURN(cpu_bringup_and_idle) +NORETURN(cpu_startup_entry) +NORETURN(do_exit) +NORETURN(do_group_exit) +NORETURN(do_task_dead) +NORETURN(ex_handler_msr_mce) +NORETURN(fortify_panic) +NORETURN(hlt_play_dead) +NORETURN(hv_ghcb_terminate) +NORETURN(kthread_complete_and_exit) +NORETURN(kthread_exit) +NORETURN(kunit_try_catch_throw) +NORETURN(machine_real_restart) +NORETURN(make_task_dead) +NORETURN(mpt_halt_firmware) +NORETURN(nmi_panic_self_stop) +NORETURN(panic) +NORETURN(panic_smp_self_stop) +NORETURN(rest_init) +NORETURN(rewind_stack_and_make_dead) +NORETURN(sev_es_terminate) +NORETURN(snp_abort) +NORETURN(start_kernel) +NORETURN(stop_this_cpu) +NORETURN(usercopy_abort) +NORETURN(x86_64_start_kernel) +NORETURN(x86_64_start_reservations) +NORETURN(xen_cpu_bringup_again) +NORETURN(xen_start_kernel) diff --git a/tools/objtool/orc_gen.c b/tools/objtool/orc_gen.c index 48efd1e2f00d..bae343908867 100644 --- a/tools/objtool/orc_gen.c +++ b/tools/objtool/orc_gen.c @@ -118,8 +118,8 @@ static int write_orc_entry(struct elf *elf, struct section *orc_sec, orc->bp_offset = bswap_if_needed(elf, orc->bp_offset); /* populate reloc for ip */ - if (elf_add_reloc_to_insn(elf, ip_sec, idx * sizeof(int), R_X86_64_PC32, - insn_sec, insn_off)) + if (!elf_init_reloc_text_sym(elf, ip_sec, idx * sizeof(int), idx, + insn_sec, insn_off)) return -1; return 0; @@ -237,12 +237,12 @@ int orc_create(struct objtool_file *file) WARN("file already has .orc_unwind section, skipping"); return -1; } - orc_sec = elf_create_section(file->elf, ".orc_unwind", 0, + orc_sec = elf_create_section(file->elf, ".orc_unwind", sizeof(struct orc_entry), nr); if (!orc_sec) return -1; - sec = elf_create_section(file->elf, ".orc_unwind_ip", 0, sizeof(int), nr); + sec = elf_create_section_pair(file->elf, ".orc_unwind_ip", sizeof(int), nr, nr); if (!sec) return -1; diff --git a/tools/objtool/special.c b/tools/objtool/special.c index baa85c31526b..91b1950f5bd8 100644 --- a/tools/objtool/special.c +++ b/tools/objtool/special.c @@ -62,7 +62,7 @@ static void reloc_to_sec_off(struct reloc *reloc, struct section **sec, unsigned long *off) { *sec = reloc->sym->sec; - *off = reloc->sym->offset + reloc->addend; + *off = reloc->sym->offset + reloc_addend(reloc); } static int get_alt_entry(struct elf *elf, const struct special_entry *entry, @@ -126,7 +126,7 @@ static int get_alt_entry(struct elf *elf, const struct special_entry *entry, sec, offset + entry->key); return -1; } - alt->key_addend = key_reloc->addend; + alt->key_addend = reloc_addend(key_reloc); } return 0; |