From eac2f3059e02382d91f8c887462083841d6ea2a3 Mon Sep 17 00:00:00 2001 From: Chen Huang Date: Thu, 29 Apr 2021 07:03:48 +0000 Subject: riscv: stacktrace: fix the riscv stacktrace when CONFIG_FRAME_POINTER enabled As [1] and [2] said, the arch_stack_walk should not to trace itself, or it will leave the trace unexpectedly when called. The example is when we do "cat /sys/kernel/debug/page_owner", all pages' stack is the same. arch_stack_walk+0x18/0x20 stack_trace_save+0x40/0x60 register_dummy_stack+0x24/0x5e init_page_owner+0x2e So we use __builtin_frame_address(1) as the first frame to be walked. And mark the arch_stack_walk() noinline. We found that pr_cont will affact pages' stack whose task state is RUNNING when testing "echo t > /proc/sysrq-trigger". So move the place of pr_cont and mark the function dump_backtrace() noinline. Also we move the case when task == NULL into else branch, and test for it in "echo c > /proc/sysrq-trigger". [1] https://lore.kernel.org/lkml/20210319184106.5688-1-mark.rutland@arm.com/ [2] https://lore.kernel.org/lkml/20210317142050.57712-1-chenjun102@huawei.com/ Signed-off-by: Chen Huang Fixes: 5d8544e2d007 ("RISC-V: Generic library routines and assembly") Cc: stable@vger.kernel.org Signed-off-by: Palmer Dabbelt --- arch/riscv/kernel/stacktrace.c | 14 +++++++------- 1 file changed, 7 insertions(+), 7 deletions(-) diff --git a/arch/riscv/kernel/stacktrace.c b/arch/riscv/kernel/stacktrace.c index 2b3e0cb90d78..bde85fc53357 100644 --- a/arch/riscv/kernel/stacktrace.c +++ b/arch/riscv/kernel/stacktrace.c @@ -27,10 +27,10 @@ void notrace walk_stackframe(struct task_struct *task, struct pt_regs *regs, fp = frame_pointer(regs); sp = user_stack_pointer(regs); pc = instruction_pointer(regs); - } else if (task == NULL || task == current) { - fp = (unsigned long)__builtin_frame_address(0); - sp = sp_in_global; - pc = (unsigned long)walk_stackframe; + } else if (task == current) { + fp = (unsigned long)__builtin_frame_address(1); + sp = (unsigned long)__builtin_frame_address(0); + pc = (unsigned long)__builtin_return_address(0); } else { /* task blocked in __switch_to */ fp = task->thread.s[0]; @@ -106,15 +106,15 @@ static bool print_trace_address(void *arg, unsigned long pc) return true; } -void dump_backtrace(struct pt_regs *regs, struct task_struct *task, +noinline void dump_backtrace(struct pt_regs *regs, struct task_struct *task, const char *loglvl) { - pr_cont("%sCall Trace:\n", loglvl); walk_stackframe(task, regs, print_trace_address, (void *)loglvl); } void show_stack(struct task_struct *task, unsigned long *sp, const char *loglvl) { + pr_cont("%sCall Trace:\n", loglvl); dump_backtrace(NULL, task, loglvl); } @@ -139,7 +139,7 @@ unsigned long get_wchan(struct task_struct *task) #ifdef CONFIG_STACKTRACE -void arch_stack_walk(stack_trace_consume_fn consume_entry, void *cookie, +noinline void arch_stack_walk(stack_trace_consume_fn consume_entry, void *cookie, struct task_struct *task, struct pt_regs *regs) { walk_stackframe(task, regs, consume_entry, cookie); -- cgit v1.2.3-58-ga151 From 97a031082320897ee5b06352d0ab3d7cf47321d3 Mon Sep 17 00:00:00 2001 From: Kefeng Wang Date: Fri, 7 May 2021 17:47:15 +0800 Subject: riscv: Select ARCH_USE_MEMTEST As of commit dce44566192e ("mm/memtest: add ARCH_USE_MEMTEST"), architectures must select ARCH_USE_MEMTESET to enable CONFIG_MEMTEST. Signed-off-by: Kefeng Wang Fixes: f6e5aedf470b ("riscv: Add support for memtest") Signed-off-by: Palmer Dabbelt --- arch/riscv/Kconfig | 1 + 1 file changed, 1 insertion(+) diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig index a8ad8eb76120..c5914e70a0fd 100644 --- a/arch/riscv/Kconfig +++ b/arch/riscv/Kconfig @@ -34,6 +34,7 @@ config RISCV select ARCH_OPTIONAL_KERNEL_RWX if ARCH_HAS_STRICT_KERNEL_RWX select ARCH_OPTIONAL_KERNEL_RWX_DEFAULT select ARCH_SUPPORTS_HUGETLBFS if MMU + select ARCH_USE_MEMTEST select ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT if MMU select ARCH_WANT_FRAME_POINTERS select ARCH_WANT_HUGE_PMD_SHARE if 64BIT -- cgit v1.2.3-58-ga151 From 02ccdeed1817a587161ad091887e11ac8a2586b2 Mon Sep 17 00:00:00 2001 From: Jisheng Zhang Date: Sat, 8 May 2021 23:43:47 +0800 Subject: riscv: kprobes: Fix build error when MMU=n lkp reported a randconfig failure: arch/riscv/kernel/probes/kprobes.c:90:22: error: use of undeclared identifier 'PAGE_KERNEL_READ_EXEC' We implemented the alloc_insn_page() to allocate PAGE_KERNEL_READ_EXEC page for kprobes insn page for STRICT_MODULE_RWX. But if MMU=n, we should fall back to the generic weak alloc_insn_page() by generic kprobe subsystem. Fixes: cdd1b2bd358f ("riscv: kprobes: Implement alloc_insn_page()") Signed-off-by: Jisheng Zhang Reported-by: kernel test robot Signed-off-by: Palmer Dabbelt --- arch/riscv/kernel/probes/kprobes.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/arch/riscv/kernel/probes/kprobes.c b/arch/riscv/kernel/probes/kprobes.c index 10b965c34536..15cc65ac7ca6 100644 --- a/arch/riscv/kernel/probes/kprobes.c +++ b/arch/riscv/kernel/probes/kprobes.c @@ -84,6 +84,7 @@ int __kprobes arch_prepare_kprobe(struct kprobe *p) return 0; } +#ifdef CONFIG_MMU void *alloc_insn_page(void) { return __vmalloc_node_range(PAGE_SIZE, 1, VMALLOC_START, VMALLOC_END, @@ -91,6 +92,7 @@ void *alloc_insn_page(void) VM_FLUSH_RESET_PERMS, NUMA_NO_NODE, __builtin_return_address(0)); } +#endif /* install breakpoint in text */ void __kprobes arch_arm_kprobe(struct kprobe *p) -- cgit v1.2.3-58-ga151 From bab0d47c0ebb50ae0bcfa4e84986a60113bf7d6b Mon Sep 17 00:00:00 2001 From: Jisheng Zhang Date: Sun, 9 May 2021 00:44:43 +0800 Subject: riscv: kexec: Fix W=1 build warnings MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Fixes the following W=1 build warning(s): In file included from include/linux/kexec.h:28, from arch/riscv/kernel/machine_kexec.c:7: arch/riscv/include/asm/kexec.h:45:1: warning: ‘extern’ is not at beginning of declaration [-Wold-style-declaration] 45 | const extern unsigned char riscv_kexec_relocate[]; | ^~~~~ arch/riscv/include/asm/kexec.h:46:1: warning: ‘extern’ is not at beginning of declaration [-Wold-style-declaration] 46 | const extern unsigned int riscv_kexec_relocate_size; | ^~~~~ arch/riscv/kernel/machine_kexec.c:125:6: warning: no previous prototype for ‘machine_shutdown’ [-Wmissing-prototypes] 125 | void machine_shutdown(void) | ^~~~~~~~~~~~~~~~ arch/riscv/kernel/machine_kexec.c:147:1: warning: no previous prototype for ‘machine_crash_shutdown’ [-Wmissing-prototypes] 147 | machine_crash_shutdown(struct pt_regs *regs) | ^~~~~~~~~~~~~~~~~~~~~~ arch/riscv/kernel/machine_kexec.c:23: warning: Function parameter or member 'image' not described in 'kexec_image_info' arch/riscv/kernel/machine_kexec.c:53: warning: Function parameter or member 'image' not described in 'machine_kexec_prepare' arch/riscv/kernel/machine_kexec.c:114: warning: Function parameter or member 'image' not described in 'machine_kexec_cleanup' arch/riscv/kernel/machine_kexec.c:148: warning: Function parameter or member 'regs' not described in 'machine_crash_shutdown' arch/riscv/kernel/machine_kexec.c:167: warning: Function parameter or member 'image' not described in 'machine_kexec' Signed-off-by: Jisheng Zhang Signed-off-by: Palmer Dabbelt --- arch/riscv/include/asm/kexec.h | 4 ++-- arch/riscv/kernel/machine_kexec.c | 11 ++++++----- 2 files changed, 8 insertions(+), 7 deletions(-) diff --git a/arch/riscv/include/asm/kexec.h b/arch/riscv/include/asm/kexec.h index 1e954101906a..e4e291d40759 100644 --- a/arch/riscv/include/asm/kexec.h +++ b/arch/riscv/include/asm/kexec.h @@ -42,8 +42,8 @@ struct kimage_arch { unsigned long fdt_addr; }; -const extern unsigned char riscv_kexec_relocate[]; -const extern unsigned int riscv_kexec_relocate_size; +extern const unsigned char riscv_kexec_relocate[]; +extern const unsigned int riscv_kexec_relocate_size; typedef void (*riscv_kexec_method)(unsigned long first_ind_entry, unsigned long jump_addr, diff --git a/arch/riscv/kernel/machine_kexec.c b/arch/riscv/kernel/machine_kexec.c index cc048143fba5..9e99e1db156b 100644 --- a/arch/riscv/kernel/machine_kexec.c +++ b/arch/riscv/kernel/machine_kexec.c @@ -14,8 +14,9 @@ #include /* For set_memory_x() */ #include /* For unreachable() */ #include /* For cpu_down() */ +#include -/** +/* * kexec_image_info - Print received image details */ static void @@ -39,7 +40,7 @@ kexec_image_info(const struct kimage *image) } } -/** +/* * machine_kexec_prepare - Initialize kexec * * This function is called from do_kexec_load, when the user has @@ -100,7 +101,7 @@ machine_kexec_prepare(struct kimage *image) } -/** +/* * machine_kexec_cleanup - Cleanup any leftovers from * machine_kexec_prepare * @@ -135,7 +136,7 @@ void machine_shutdown(void) #endif } -/** +/* * machine_crash_shutdown - Prepare to kexec after a kernel crash * * This function is called by crash_kexec just before machine_kexec @@ -151,7 +152,7 @@ machine_crash_shutdown(struct pt_regs *regs) pr_info("Starting crashdump kernel...\n"); } -/** +/* * machine_kexec - Jump to the loaded kimage * * This function is called by kernel_kexec which is called by the -- cgit v1.2.3-58-ga151