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-rw-r--r--lib/Makefile3
-rw-r--r--lib/buildid.c149
-rw-r--r--lib/test_bpf.c14
3 files changed, 158 insertions, 8 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/test_bpf.c b/lib/test_bpf.c
index ca7d635bccd9..49ec9e8d8aed 100644
--- a/lib/test_bpf.c
+++ b/lib/test_bpf.c
@@ -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,
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-16 11:46:23 +0000