diff options
| -rw-r--r-- | fs/proc/task_mmu.c | 42 | ||||
| -rw-r--r-- | include/linux/buildid.h | 3 | ||||
| -rw-r--r-- | lib/buildid.c | 42 |
3 files changed, 60 insertions, 27 deletions
diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c index 81dfc26bfae8..26188a4ad1ab 100644 --- a/fs/proc/task_mmu.c +++ b/fs/proc/task_mmu.c @@ -656,6 +656,7 @@ static int do_procmap_query(struct mm_struct *mm, void __user *uarg) struct proc_maps_locking_ctx lock_ctx = { .mm = mm }; struct procmap_query karg; struct vm_area_struct *vma; + struct file *vm_file = NULL; const char *name = NULL; char build_id_buf[BUILD_ID_SIZE_MAX], *name_buf = NULL; __u64 usize; @@ -727,21 +728,6 @@ static int do_procmap_query(struct mm_struct *mm, void __user *uarg) karg.inode = 0; } - if (karg.build_id_size) { - __u32 build_id_sz; - - err = build_id_parse(vma, build_id_buf, &build_id_sz); - if (err) { - karg.build_id_size = 0; - } else { - if (karg.build_id_size < build_id_sz) { - err = -ENAMETOOLONG; - goto out; - } - karg.build_id_size = build_id_sz; - } - } - if (karg.vma_name_size) { size_t name_buf_sz = min_t(size_t, PATH_MAX, karg.vma_name_size); const struct path *path; @@ -775,10 +761,34 @@ static int do_procmap_query(struct mm_struct *mm, void __user *uarg) karg.vma_name_size = name_sz; } + if (karg.build_id_size && vma->vm_file) + vm_file = get_file(vma->vm_file); + /* unlock vma or mmap_lock, and put mm_struct before copying data to user */ query_vma_teardown(&lock_ctx); mmput(mm); + if (karg.build_id_size) { + __u32 build_id_sz; + + if (vm_file) + err = build_id_parse_file(vm_file, build_id_buf, &build_id_sz); + else + err = -ENOENT; + if (err) { + karg.build_id_size = 0; + } else { + if (karg.build_id_size < build_id_sz) { + err = -ENAMETOOLONG; + goto out; + } + karg.build_id_size = build_id_sz; + } + } + + if (vm_file) + fput(vm_file); + if (karg.vma_name_size && copy_to_user(u64_to_user_ptr(karg.vma_name_addr), name, karg.vma_name_size)) { kfree(name_buf); @@ -798,6 +808,8 @@ static int do_procmap_query(struct mm_struct *mm, void __user *uarg) out: query_vma_teardown(&lock_ctx); mmput(mm); + if (vm_file) + fput(vm_file); kfree(name_buf); return err; } diff --git a/include/linux/buildid.h b/include/linux/buildid.h index 831c1b4b626c..7acc06b22fb7 100644 --- a/include/linux/buildid.h +++ b/include/linux/buildid.h @@ -7,7 +7,10 @@ #define BUILD_ID_SIZE_MAX 20 struct vm_area_struct; +struct file; + int build_id_parse(struct vm_area_struct *vma, unsigned char *build_id, __u32 *size); +int build_id_parse_file(struct file *file, unsigned char *build_id, __u32 *size); int build_id_parse_nofault(struct vm_area_struct *vma, unsigned char *build_id, __u32 *size); int build_id_parse_buf(const void *buf, unsigned char *build_id, u32 buf_size); diff --git a/lib/buildid.c b/lib/buildid.c index 818331051afe..c4b737640621 100644 --- a/lib/buildid.c +++ b/lib/buildid.c @@ -279,7 +279,7 @@ static int get_build_id_64(struct freader *r, unsigned char *build_id, __u32 *si /* enough for Elf64_Ehdr, Elf64_Phdr, and all the smaller requests */ #define MAX_FREADER_BUF_SZ 64 -static int __build_id_parse(struct vm_area_struct *vma, unsigned char *build_id, +static int __build_id_parse(struct file *file, unsigned char *build_id, __u32 *size, bool may_fault) { const Elf32_Ehdr *ehdr; @@ -287,11 +287,7 @@ static int __build_id_parse(struct vm_area_struct *vma, unsigned char *build_id, char buf[MAX_FREADER_BUF_SZ]; int ret; - /* only works for page backed storage */ - if (!vma->vm_file) - return -EINVAL; - - freader_init_from_file(&r, buf, sizeof(buf), vma->vm_file, may_fault); + freader_init_from_file(&r, buf, sizeof(buf), file, may_fault); /* fetch first 18 bytes of ELF header for checks */ ehdr = freader_fetch(&r, 0, offsetofend(Elf32_Ehdr, e_type)); @@ -319,8 +315,8 @@ out: return ret; } -/* - * Parse build ID of ELF file mapped to vma +/** + * build_id_parse_nofault() - 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 @@ -332,11 +328,14 @@ out: */ int build_id_parse_nofault(struct vm_area_struct *vma, unsigned char *build_id, __u32 *size) { - return __build_id_parse(vma, build_id, size, false /* !may_fault */); + if (!vma->vm_file) + return -EINVAL; + + return __build_id_parse(vma->vm_file, build_id, size, false /* !may_fault */); } -/* - * Parse build ID of ELF file mapped to VMA +/** + * build_id_parse() - 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 @@ -348,7 +347,26 @@ int build_id_parse_nofault(struct vm_area_struct *vma, unsigned char *build_id, */ int build_id_parse(struct vm_area_struct *vma, unsigned char *build_id, __u32 *size) { - return __build_id_parse(vma, build_id, size, true /* may_fault */); + if (!vma->vm_file) + return -EINVAL; + + return __build_id_parse(vma->vm_file, build_id, size, true /* may_fault */); +} + +/** + * build_id_parse_file() - Parse build ID of ELF file + * @file: file object + * @build_id: buffer to store build id, at least BUILD_ID_SIZE long + * @size: returns actual build id size in case of success + * + * Assumes faultable context and can cause page faults to bring in file data + * into page cache. + * + * Return: 0 on success; negative error, otherwise + */ +int build_id_parse_file(struct file *file, unsigned char *build_id, __u32 *size) +{ + return __build_id_parse(file, build_id, size, true /* may_fault */); } /** |