diff options
Diffstat (limited to 'lib')
-rw-r--r-- | lib/Makefile | 3 | ||||
-rw-r--r-- | lib/buildid.c | 149 | ||||
-rw-r--r-- | lib/parman.c | 1 | ||||
-rw-r--r-- | lib/test_bpf.c | 21 |
4 files changed, 159 insertions, 15 deletions
diff --git a/lib/Makefile b/lib/Makefile index afeff05fa8c5..a6b160c3a4fa 100644 --- a/lib/Makefile +++ b/lib/Makefile @@ -36,7 +36,8 @@ lib-y := ctype.o string.o vsprintf.o cmdline.o \ flex_proportions.o ratelimit.o show_mem.o \ is_single_threaded.o plist.o decompress.o kobject_uevent.o \ earlycpio.o seq_buf.o siphash.o dec_and_lock.o \ - nmi_backtrace.o nodemask.o win_minmax.o memcat_p.o + nmi_backtrace.o nodemask.o win_minmax.o memcat_p.o \ + buildid.o lib-$(CONFIG_PRINTK) += dump_stack.o lib-$(CONFIG_SMP) += cpumask.o diff --git a/lib/buildid.c b/lib/buildid.c new file mode 100644 index 000000000000..6156997c3895 --- /dev/null +++ b/lib/buildid.c @@ -0,0 +1,149 @@ +// SPDX-License-Identifier: GPL-2.0 + +#include <linux/buildid.h> +#include <linux/elf.h> +#include <linux/pagemap.h> + +#define BUILD_ID 3 +/* + * Parse build id from the note segment. This logic can be shared between + * 32-bit and 64-bit system, because Elf32_Nhdr and Elf64_Nhdr are + * identical. + */ +static inline int parse_build_id(void *page_addr, + unsigned char *build_id, + __u32 *size, + void *note_start, + Elf32_Word note_size) +{ + Elf32_Word note_offs = 0, new_offs; + + /* check for overflow */ + if (note_start < page_addr || note_start + note_size < note_start) + return -EINVAL; + + /* only supports note that fits in the first page */ + if (note_start + note_size > page_addr + PAGE_SIZE) + return -EINVAL; + + while (note_offs + sizeof(Elf32_Nhdr) < note_size) { + Elf32_Nhdr *nhdr = (Elf32_Nhdr *)(note_start + note_offs); + + if (nhdr->n_type == BUILD_ID && + nhdr->n_namesz == sizeof("GNU") && + nhdr->n_descsz > 0 && + nhdr->n_descsz <= BUILD_ID_SIZE_MAX) { + memcpy(build_id, + note_start + note_offs + + ALIGN(sizeof("GNU"), 4) + sizeof(Elf32_Nhdr), + nhdr->n_descsz); + memset(build_id + nhdr->n_descsz, 0, + BUILD_ID_SIZE_MAX - nhdr->n_descsz); + if (size) + *size = nhdr->n_descsz; + return 0; + } + new_offs = note_offs + sizeof(Elf32_Nhdr) + + ALIGN(nhdr->n_namesz, 4) + ALIGN(nhdr->n_descsz, 4); + if (new_offs <= note_offs) /* overflow */ + break; + note_offs = new_offs; + } + return -EINVAL; +} + +/* Parse build ID from 32-bit ELF */ +static int get_build_id_32(void *page_addr, unsigned char *build_id, + __u32 *size) +{ + Elf32_Ehdr *ehdr = (Elf32_Ehdr *)page_addr; + Elf32_Phdr *phdr; + int i; + + /* only supports phdr that fits in one page */ + if (ehdr->e_phnum > + (PAGE_SIZE - sizeof(Elf32_Ehdr)) / sizeof(Elf32_Phdr)) + return -EINVAL; + + phdr = (Elf32_Phdr *)(page_addr + sizeof(Elf32_Ehdr)); + + for (i = 0; i < ehdr->e_phnum; ++i) { + if (phdr[i].p_type == PT_NOTE && + !parse_build_id(page_addr, build_id, size, + page_addr + phdr[i].p_offset, + phdr[i].p_filesz)) + return 0; + } + return -EINVAL; +} + +/* Parse build ID from 64-bit ELF */ +static int get_build_id_64(void *page_addr, unsigned char *build_id, + __u32 *size) +{ + Elf64_Ehdr *ehdr = (Elf64_Ehdr *)page_addr; + Elf64_Phdr *phdr; + int i; + + /* only supports phdr that fits in one page */ + if (ehdr->e_phnum > + (PAGE_SIZE - sizeof(Elf64_Ehdr)) / sizeof(Elf64_Phdr)) + return -EINVAL; + + phdr = (Elf64_Phdr *)(page_addr + sizeof(Elf64_Ehdr)); + + for (i = 0; i < ehdr->e_phnum; ++i) { + if (phdr[i].p_type == PT_NOTE && + !parse_build_id(page_addr, build_id, size, + page_addr + phdr[i].p_offset, + phdr[i].p_filesz)) + return 0; + } + return -EINVAL; +} + +/* + * Parse build ID of ELF file mapped to vma + * @vma: vma object + * @build_id: buffer to store build id, at least BUILD_ID_SIZE long + * @size: returns actual build id size in case of success + * + * Returns 0 on success, otherwise error (< 0). + */ +int build_id_parse(struct vm_area_struct *vma, unsigned char *build_id, + __u32 *size) +{ + Elf32_Ehdr *ehdr; + struct page *page; + void *page_addr; + int ret; + + /* only works for page backed storage */ + if (!vma->vm_file) + return -EINVAL; + + page = find_get_page(vma->vm_file->f_mapping, 0); + if (!page) + return -EFAULT; /* page not mapped */ + + ret = -EINVAL; + page_addr = kmap_atomic(page); + ehdr = (Elf32_Ehdr *)page_addr; + + /* compare magic x7f "ELF" */ + if (memcmp(ehdr->e_ident, ELFMAG, SELFMAG) != 0) + goto out; + + /* only support executable file and shared object file */ + if (ehdr->e_type != ET_EXEC && ehdr->e_type != ET_DYN) + goto out; + + if (ehdr->e_ident[EI_CLASS] == ELFCLASS32) + ret = get_build_id_32(page_addr, build_id, size); + else if (ehdr->e_ident[EI_CLASS] == ELFCLASS64) + ret = get_build_id_64(page_addr, build_id, size); +out: + kunmap_atomic(page_addr); + put_page(page); + return ret; +} diff --git a/lib/parman.c b/lib/parman.c index c6e42a8db824..a11f2f667639 100644 --- a/lib/parman.c +++ b/lib/parman.c @@ -85,7 +85,6 @@ static int parman_shrink(struct parman *parman) } static bool parman_prio_used(struct parman_prio *prio) - { return !list_empty(&prio->item_list); } diff --git a/lib/test_bpf.c b/lib/test_bpf.c index ca7d635bccd9..4dc4dcbecd12 100644 --- a/lib/test_bpf.c +++ b/lib/test_bpf.c @@ -345,7 +345,7 @@ static int __bpf_fill_ja(struct bpf_test *self, unsigned int len, static int bpf_fill_maxinsns11(struct bpf_test *self) { - /* Hits 70 passes on x86_64, so cannot get JITed there. */ + /* Hits 70 passes on x86_64 and triggers NOPs padding. */ return __bpf_fill_ja(self, BPF_MAXINSNS, 68); } @@ -4295,13 +4295,13 @@ static struct bpf_test tests[] = { { { 0, 0xffffffff } }, .stack_depth = 40, }, - /* BPF_STX | BPF_XADD | BPF_W/DW */ + /* BPF_STX | BPF_ATOMIC | BPF_W/DW */ { "STX_XADD_W: Test: 0x12 + 0x10 = 0x22", .u.insns_int = { BPF_ALU32_IMM(BPF_MOV, R0, 0x12), BPF_ST_MEM(BPF_W, R10, -40, 0x10), - BPF_STX_XADD(BPF_W, R10, R0, -40), + BPF_ATOMIC_OP(BPF_W, BPF_ADD, R10, R0, -40), BPF_LDX_MEM(BPF_W, R0, R10, -40), BPF_EXIT_INSN(), }, @@ -4316,7 +4316,7 @@ static struct bpf_test tests[] = { BPF_ALU64_REG(BPF_MOV, R1, R10), BPF_ALU32_IMM(BPF_MOV, R0, 0x12), BPF_ST_MEM(BPF_W, R10, -40, 0x10), - BPF_STX_XADD(BPF_W, R10, R0, -40), + BPF_ATOMIC_OP(BPF_W, BPF_ADD, R10, R0, -40), BPF_ALU64_REG(BPF_MOV, R0, R10), BPF_ALU64_REG(BPF_SUB, R0, R1), BPF_EXIT_INSN(), @@ -4331,7 +4331,7 @@ static struct bpf_test tests[] = { .u.insns_int = { BPF_ALU32_IMM(BPF_MOV, R0, 0x12), BPF_ST_MEM(BPF_W, R10, -40, 0x10), - BPF_STX_XADD(BPF_W, R10, R0, -40), + BPF_ATOMIC_OP(BPF_W, BPF_ADD, R10, R0, -40), BPF_EXIT_INSN(), }, INTERNAL, @@ -4352,7 +4352,7 @@ static struct bpf_test tests[] = { .u.insns_int = { BPF_ALU32_IMM(BPF_MOV, R0, 0x12), BPF_ST_MEM(BPF_DW, R10, -40, 0x10), - BPF_STX_XADD(BPF_DW, R10, R0, -40), + BPF_ATOMIC_OP(BPF_DW, BPF_ADD, R10, R0, -40), BPF_LDX_MEM(BPF_DW, R0, R10, -40), BPF_EXIT_INSN(), }, @@ -4367,7 +4367,7 @@ static struct bpf_test tests[] = { BPF_ALU64_REG(BPF_MOV, R1, R10), BPF_ALU32_IMM(BPF_MOV, R0, 0x12), BPF_ST_MEM(BPF_DW, R10, -40, 0x10), - BPF_STX_XADD(BPF_DW, R10, R0, -40), + BPF_ATOMIC_OP(BPF_DW, BPF_ADD, R10, R0, -40), BPF_ALU64_REG(BPF_MOV, R0, R10), BPF_ALU64_REG(BPF_SUB, R0, R1), BPF_EXIT_INSN(), @@ -4382,7 +4382,7 @@ static struct bpf_test tests[] = { .u.insns_int = { BPF_ALU32_IMM(BPF_MOV, R0, 0x12), BPF_ST_MEM(BPF_DW, R10, -40, 0x10), - BPF_STX_XADD(BPF_DW, R10, R0, -40), + BPF_ATOMIC_OP(BPF_DW, BPF_ADD, R10, R0, -40), BPF_EXIT_INSN(), }, INTERNAL, @@ -5318,15 +5318,10 @@ static struct bpf_test tests[] = { { "BPF_MAXINSNS: Jump, gap, jump, ...", { }, -#if defined(CONFIG_BPF_JIT_ALWAYS_ON) && defined(CONFIG_X86) - CLASSIC | FLAG_NO_DATA | FLAG_EXPECTED_FAIL, -#else CLASSIC | FLAG_NO_DATA, -#endif { }, { { 0, 0xababcbac } }, .fill_helper = bpf_fill_maxinsns11, - .expected_errcode = -ENOTSUPP, }, { "BPF_MAXINSNS: jump over MSH", |