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-rw-r--r--fs/proc/vmcore.c359
1 files changed, 286 insertions, 73 deletions
diff --git a/fs/proc/vmcore.c b/fs/proc/vmcore.c
index 78c87a1ac01a..9b9270eb0599 100644
--- a/fs/proc/vmcore.c
+++ b/fs/proc/vmcore.c
@@ -34,6 +34,9 @@ static char *elfcorebuf;
static size_t elfcorebuf_sz;
static size_t elfcorebuf_sz_orig;
+static char *elfnotes_buf;
+static size_t elfnotes_sz;
+
/* Total size of vmcore file. */
static u64 vmcore_size;
@@ -139,9 +142,7 @@ static ssize_t read_vmcore(struct file *file, char __user *buffer,
/* Read ELF core header */
if (*fpos < elfcorebuf_sz) {
- tsz = elfcorebuf_sz - *fpos;
- if (buflen < tsz)
- tsz = buflen;
+ tsz = min(elfcorebuf_sz - (size_t)*fpos, buflen);
if (copy_to_user(buffer, elfcorebuf + *fpos, tsz))
return -EFAULT;
buflen -= tsz;
@@ -154,11 +155,27 @@ static ssize_t read_vmcore(struct file *file, char __user *buffer,
return acc;
}
+ /* Read Elf note segment */
+ if (*fpos < elfcorebuf_sz + elfnotes_sz) {
+ void *kaddr;
+
+ tsz = min(elfcorebuf_sz + elfnotes_sz - (size_t)*fpos, buflen);
+ kaddr = elfnotes_buf + *fpos - elfcorebuf_sz;
+ if (copy_to_user(buffer, kaddr, tsz))
+ return -EFAULT;
+ buflen -= tsz;
+ *fpos += tsz;
+ buffer += tsz;
+ acc += tsz;
+
+ /* leave now if filled buffer already */
+ if (buflen == 0)
+ return acc;
+ }
+
list_for_each_entry(m, &vmcore_list, list) {
if (*fpos < m->offset + m->size) {
- tsz = m->offset + m->size - *fpos;
- if (buflen < tsz)
- tsz = buflen;
+ tsz = min_t(size_t, m->offset + m->size - *fpos, buflen);
start = m->paddr + *fpos - m->offset;
tmp = read_from_oldmem(buffer, tsz, &start, 1);
if (tmp < 0)
@@ -221,27 +238,27 @@ static u64 __init get_vmcore_size_elf32(char *elfptr, size_t elfsz)
return size;
}
-/* Merges all the PT_NOTE headers into one. */
-static int __init merge_note_headers_elf64(char *elfptr, size_t *elfsz,
- struct list_head *vc_list)
+/**
+ * update_note_header_size_elf64 - update p_memsz member of each PT_NOTE entry
+ *
+ * @ehdr_ptr: ELF header
+ *
+ * This function updates p_memsz member of each PT_NOTE entry in the
+ * program header table pointed to by @ehdr_ptr to real size of ELF
+ * note segment.
+ */
+static int __init update_note_header_size_elf64(const Elf64_Ehdr *ehdr_ptr)
{
- int i, nr_ptnote=0, rc=0;
- char *tmp;
- Elf64_Ehdr *ehdr_ptr;
- Elf64_Phdr phdr, *phdr_ptr;
+ int i, rc=0;
+ Elf64_Phdr *phdr_ptr;
Elf64_Nhdr *nhdr_ptr;
- u64 phdr_sz = 0, note_off;
- ehdr_ptr = (Elf64_Ehdr *)elfptr;
- phdr_ptr = (Elf64_Phdr*)(elfptr + sizeof(Elf64_Ehdr));
+ phdr_ptr = (Elf64_Phdr *)(ehdr_ptr + 1);
for (i = 0; i < ehdr_ptr->e_phnum; i++, phdr_ptr++) {
- int j;
void *notes_section;
- struct vmcore *new;
u64 offset, max_sz, sz, real_sz = 0;
if (phdr_ptr->p_type != PT_NOTE)
continue;
- nr_ptnote++;
max_sz = phdr_ptr->p_memsz;
offset = phdr_ptr->p_offset;
notes_section = kmalloc(max_sz, GFP_KERNEL);
@@ -253,7 +270,7 @@ static int __init merge_note_headers_elf64(char *elfptr, size_t *elfsz,
return rc;
}
nhdr_ptr = notes_section;
- for (j = 0; j < max_sz; j += sz) {
+ while (real_sz < max_sz) {
if (nhdr_ptr->n_namesz == 0)
break;
sz = sizeof(Elf64_Nhdr) +
@@ -262,26 +279,122 @@ static int __init merge_note_headers_elf64(char *elfptr, size_t *elfsz,
real_sz += sz;
nhdr_ptr = (Elf64_Nhdr*)((char*)nhdr_ptr + sz);
}
-
- /* Add this contiguous chunk of notes section to vmcore list.*/
- new = get_new_element();
- if (!new) {
- kfree(notes_section);
- return -ENOMEM;
- }
- new->paddr = phdr_ptr->p_offset;
- new->size = real_sz;
- list_add_tail(&new->list, vc_list);
- phdr_sz += real_sz;
kfree(notes_section);
+ phdr_ptr->p_memsz = real_sz;
}
+ return 0;
+}
+
+/**
+ * get_note_number_and_size_elf64 - get the number of PT_NOTE program
+ * headers and sum of real size of their ELF note segment headers and
+ * data.
+ *
+ * @ehdr_ptr: ELF header
+ * @nr_ptnote: buffer for the number of PT_NOTE program headers
+ * @sz_ptnote: buffer for size of unique PT_NOTE program header
+ *
+ * This function is used to merge multiple PT_NOTE program headers
+ * into a unique single one. The resulting unique entry will have
+ * @sz_ptnote in its phdr->p_mem.
+ *
+ * It is assumed that program headers with PT_NOTE type pointed to by
+ * @ehdr_ptr has already been updated by update_note_header_size_elf64
+ * and each of PT_NOTE program headers has actual ELF note segment
+ * size in its p_memsz member.
+ */
+static int __init get_note_number_and_size_elf64(const Elf64_Ehdr *ehdr_ptr,
+ int *nr_ptnote, u64 *sz_ptnote)
+{
+ int i;
+ Elf64_Phdr *phdr_ptr;
+
+ *nr_ptnote = *sz_ptnote = 0;
+
+ phdr_ptr = (Elf64_Phdr *)(ehdr_ptr + 1);
+ for (i = 0; i < ehdr_ptr->e_phnum; i++, phdr_ptr++) {
+ if (phdr_ptr->p_type != PT_NOTE)
+ continue;
+ *nr_ptnote += 1;
+ *sz_ptnote += phdr_ptr->p_memsz;
+ }
+
+ return 0;
+}
+
+/**
+ * copy_notes_elf64 - copy ELF note segments in a given buffer
+ *
+ * @ehdr_ptr: ELF header
+ * @notes_buf: buffer into which ELF note segments are copied
+ *
+ * This function is used to copy ELF note segment in the 1st kernel
+ * into the buffer @notes_buf in the 2nd kernel. It is assumed that
+ * size of the buffer @notes_buf is equal to or larger than sum of the
+ * real ELF note segment headers and data.
+ *
+ * It is assumed that program headers with PT_NOTE type pointed to by
+ * @ehdr_ptr has already been updated by update_note_header_size_elf64
+ * and each of PT_NOTE program headers has actual ELF note segment
+ * size in its p_memsz member.
+ */
+static int __init copy_notes_elf64(const Elf64_Ehdr *ehdr_ptr, char *notes_buf)
+{
+ int i, rc=0;
+ Elf64_Phdr *phdr_ptr;
+
+ phdr_ptr = (Elf64_Phdr*)(ehdr_ptr + 1);
+
+ for (i = 0; i < ehdr_ptr->e_phnum; i++, phdr_ptr++) {
+ u64 offset;
+ if (phdr_ptr->p_type != PT_NOTE)
+ continue;
+ offset = phdr_ptr->p_offset;
+ rc = read_from_oldmem(notes_buf, phdr_ptr->p_memsz, &offset, 0);
+ if (rc < 0)
+ return rc;
+ notes_buf += phdr_ptr->p_memsz;
+ }
+
+ return 0;
+}
+
+/* Merges all the PT_NOTE headers into one. */
+static int __init merge_note_headers_elf64(char *elfptr, size_t *elfsz,
+ char **notes_buf, size_t *notes_sz)
+{
+ int i, nr_ptnote=0, rc=0;
+ char *tmp;
+ Elf64_Ehdr *ehdr_ptr;
+ Elf64_Phdr phdr;
+ u64 phdr_sz = 0, note_off;
+
+ ehdr_ptr = (Elf64_Ehdr *)elfptr;
+
+ rc = update_note_header_size_elf64(ehdr_ptr);
+ if (rc < 0)
+ return rc;
+
+ rc = get_note_number_and_size_elf64(ehdr_ptr, &nr_ptnote, &phdr_sz);
+ if (rc < 0)
+ return rc;
+
+ *notes_sz = roundup(phdr_sz, PAGE_SIZE);
+ *notes_buf = vzalloc(*notes_sz);
+ if (!*notes_buf)
+ return -ENOMEM;
+
+ rc = copy_notes_elf64(ehdr_ptr, *notes_buf);
+ if (rc < 0)
+ return rc;
+
/* Prepare merged PT_NOTE program header. */
phdr.p_type = PT_NOTE;
phdr.p_flags = 0;
note_off = sizeof(Elf64_Ehdr) +
(ehdr_ptr->e_phnum - nr_ptnote +1) * sizeof(Elf64_Phdr);
- phdr.p_offset = note_off;
+ phdr.p_offset = roundup(note_off, PAGE_SIZE);
phdr.p_vaddr = phdr.p_paddr = 0;
phdr.p_filesz = phdr.p_memsz = phdr_sz;
phdr.p_align = 0;
@@ -304,27 +417,27 @@ static int __init merge_note_headers_elf64(char *elfptr, size_t *elfsz,
return 0;
}
-/* Merges all the PT_NOTE headers into one. */
-static int __init merge_note_headers_elf32(char *elfptr, size_t *elfsz,
- struct list_head *vc_list)
+/**
+ * update_note_header_size_elf32 - update p_memsz member of each PT_NOTE entry
+ *
+ * @ehdr_ptr: ELF header
+ *
+ * This function updates p_memsz member of each PT_NOTE entry in the
+ * program header table pointed to by @ehdr_ptr to real size of ELF
+ * note segment.
+ */
+static int __init update_note_header_size_elf32(const Elf32_Ehdr *ehdr_ptr)
{
- int i, nr_ptnote=0, rc=0;
- char *tmp;
- Elf32_Ehdr *ehdr_ptr;
- Elf32_Phdr phdr, *phdr_ptr;
+ int i, rc=0;
+ Elf32_Phdr *phdr_ptr;
Elf32_Nhdr *nhdr_ptr;
- u64 phdr_sz = 0, note_off;
- ehdr_ptr = (Elf32_Ehdr *)elfptr;
- phdr_ptr = (Elf32_Phdr*)(elfptr + sizeof(Elf32_Ehdr));
+ phdr_ptr = (Elf32_Phdr *)(ehdr_ptr + 1);
for (i = 0; i < ehdr_ptr->e_phnum; i++, phdr_ptr++) {
- int j;
void *notes_section;
- struct vmcore *new;
u64 offset, max_sz, sz, real_sz = 0;
if (phdr_ptr->p_type != PT_NOTE)
continue;
- nr_ptnote++;
max_sz = phdr_ptr->p_memsz;
offset = phdr_ptr->p_offset;
notes_section = kmalloc(max_sz, GFP_KERNEL);
@@ -336,7 +449,7 @@ static int __init merge_note_headers_elf32(char *elfptr, size_t *elfsz,
return rc;
}
nhdr_ptr = notes_section;
- for (j = 0; j < max_sz; j += sz) {
+ while (real_sz < max_sz) {
if (nhdr_ptr->n_namesz == 0)
break;
sz = sizeof(Elf32_Nhdr) +
@@ -345,26 +458,122 @@ static int __init merge_note_headers_elf32(char *elfptr, size_t *elfsz,
real_sz += sz;
nhdr_ptr = (Elf32_Nhdr*)((char*)nhdr_ptr + sz);
}
-
- /* Add this contiguous chunk of notes section to vmcore list.*/
- new = get_new_element();
- if (!new) {
- kfree(notes_section);
- return -ENOMEM;
- }
- new->paddr = phdr_ptr->p_offset;
- new->size = real_sz;
- list_add_tail(&new->list, vc_list);
- phdr_sz += real_sz;
kfree(notes_section);
+ phdr_ptr->p_memsz = real_sz;
+ }
+
+ return 0;
+}
+
+/**
+ * get_note_number_and_size_elf32 - get the number of PT_NOTE program
+ * headers and sum of real size of their ELF note segment headers and
+ * data.
+ *
+ * @ehdr_ptr: ELF header
+ * @nr_ptnote: buffer for the number of PT_NOTE program headers
+ * @sz_ptnote: buffer for size of unique PT_NOTE program header
+ *
+ * This function is used to merge multiple PT_NOTE program headers
+ * into a unique single one. The resulting unique entry will have
+ * @sz_ptnote in its phdr->p_mem.
+ *
+ * It is assumed that program headers with PT_NOTE type pointed to by
+ * @ehdr_ptr has already been updated by update_note_header_size_elf32
+ * and each of PT_NOTE program headers has actual ELF note segment
+ * size in its p_memsz member.
+ */
+static int __init get_note_number_and_size_elf32(const Elf32_Ehdr *ehdr_ptr,
+ int *nr_ptnote, u64 *sz_ptnote)
+{
+ int i;
+ Elf32_Phdr *phdr_ptr;
+
+ *nr_ptnote = *sz_ptnote = 0;
+
+ phdr_ptr = (Elf32_Phdr *)(ehdr_ptr + 1);
+ for (i = 0; i < ehdr_ptr->e_phnum; i++, phdr_ptr++) {
+ if (phdr_ptr->p_type != PT_NOTE)
+ continue;
+ *nr_ptnote += 1;
+ *sz_ptnote += phdr_ptr->p_memsz;
}
+ return 0;
+}
+
+/**
+ * copy_notes_elf32 - copy ELF note segments in a given buffer
+ *
+ * @ehdr_ptr: ELF header
+ * @notes_buf: buffer into which ELF note segments are copied
+ *
+ * This function is used to copy ELF note segment in the 1st kernel
+ * into the buffer @notes_buf in the 2nd kernel. It is assumed that
+ * size of the buffer @notes_buf is equal to or larger than sum of the
+ * real ELF note segment headers and data.
+ *
+ * It is assumed that program headers with PT_NOTE type pointed to by
+ * @ehdr_ptr has already been updated by update_note_header_size_elf32
+ * and each of PT_NOTE program headers has actual ELF note segment
+ * size in its p_memsz member.
+ */
+static int __init copy_notes_elf32(const Elf32_Ehdr *ehdr_ptr, char *notes_buf)
+{
+ int i, rc=0;
+ Elf32_Phdr *phdr_ptr;
+
+ phdr_ptr = (Elf32_Phdr*)(ehdr_ptr + 1);
+
+ for (i = 0; i < ehdr_ptr->e_phnum; i++, phdr_ptr++) {
+ u64 offset;
+ if (phdr_ptr->p_type != PT_NOTE)
+ continue;
+ offset = phdr_ptr->p_offset;
+ rc = read_from_oldmem(notes_buf, phdr_ptr->p_memsz, &offset, 0);
+ if (rc < 0)
+ return rc;
+ notes_buf += phdr_ptr->p_memsz;
+ }
+
+ return 0;
+}
+
+/* Merges all the PT_NOTE headers into one. */
+static int __init merge_note_headers_elf32(char *elfptr, size_t *elfsz,
+ char **notes_buf, size_t *notes_sz)
+{
+ int i, nr_ptnote=0, rc=0;
+ char *tmp;
+ Elf32_Ehdr *ehdr_ptr;
+ Elf32_Phdr phdr;
+ u64 phdr_sz = 0, note_off;
+
+ ehdr_ptr = (Elf32_Ehdr *)elfptr;
+
+ rc = update_note_header_size_elf32(ehdr_ptr);
+ if (rc < 0)
+ return rc;
+
+ rc = get_note_number_and_size_elf32(ehdr_ptr, &nr_ptnote, &phdr_sz);
+ if (rc < 0)
+ return rc;
+
+ *notes_sz = roundup(phdr_sz, PAGE_SIZE);
+ *notes_buf = vzalloc(*notes_sz);
+ if (!*notes_buf)
+ return -ENOMEM;
+
+ rc = copy_notes_elf32(ehdr_ptr, *notes_buf);
+ if (rc < 0)
+ return rc;
+
/* Prepare merged PT_NOTE program header. */
phdr.p_type = PT_NOTE;
phdr.p_flags = 0;
note_off = sizeof(Elf32_Ehdr) +
(ehdr_ptr->e_phnum - nr_ptnote +1) * sizeof(Elf32_Phdr);
- phdr.p_offset = note_off;
+ phdr.p_offset = roundup(note_off, PAGE_SIZE);
phdr.p_vaddr = phdr.p_paddr = 0;
phdr.p_filesz = phdr.p_memsz = phdr_sz;
phdr.p_align = 0;
@@ -391,6 +600,7 @@ static int __init merge_note_headers_elf32(char *elfptr, size_t *elfsz,
* the new offset fields of exported program headers. */
static int __init process_ptload_program_headers_elf64(char *elfptr,
size_t elfsz,
+ size_t elfnotes_sz,
struct list_head *vc_list)
{
int i;
@@ -402,9 +612,8 @@ static int __init process_ptload_program_headers_elf64(char *elfptr,
ehdr_ptr = (Elf64_Ehdr *)elfptr;
phdr_ptr = (Elf64_Phdr*)(elfptr + sizeof(Elf64_Ehdr)); /* PT_NOTE hdr */
- /* First program header is PT_NOTE header. */
- vmcore_off = elfsz +
- phdr_ptr->p_memsz; /* Note sections */
+ /* Skip Elf header, program headers and Elf note segment. */
+ vmcore_off = elfsz + elfnotes_sz;
for (i = 0; i < ehdr_ptr->e_phnum; i++, phdr_ptr++) {
u64 paddr, start, end, size;
@@ -434,6 +643,7 @@ static int __init process_ptload_program_headers_elf64(char *elfptr,
static int __init process_ptload_program_headers_elf32(char *elfptr,
size_t elfsz,
+ size_t elfnotes_sz,
struct list_head *vc_list)
{
int i;
@@ -445,9 +655,8 @@ static int __init process_ptload_program_headers_elf32(char *elfptr,
ehdr_ptr = (Elf32_Ehdr *)elfptr;
phdr_ptr = (Elf32_Phdr*)(elfptr + sizeof(Elf32_Ehdr)); /* PT_NOTE hdr */
- /* First program header is PT_NOTE header. */
- vmcore_off = elfsz +
- phdr_ptr->p_memsz; /* Note sections */
+ /* Skip Elf header, program headers and Elf note segment. */
+ vmcore_off = elfsz + elfnotes_sz;
for (i = 0; i < ehdr_ptr->e_phnum; i++, phdr_ptr++) {
u64 paddr, start, end, size;
@@ -476,14 +685,14 @@ static int __init process_ptload_program_headers_elf32(char *elfptr,
}
/* Sets offset fields of vmcore elements. */
-static void __init set_vmcore_list_offsets(size_t elfsz,
+static void __init set_vmcore_list_offsets(size_t elfsz, size_t elfnotes_sz,
struct list_head *vc_list)
{
loff_t vmcore_off;
struct vmcore *m;
- /* Skip Elf header and program headers. */
- vmcore_off = elfsz;
+ /* Skip Elf header, program headers and Elf note segment. */
+ vmcore_off = elfsz + elfnotes_sz;
list_for_each_entry(m, vc_list, list) {
m->offset = vmcore_off;
@@ -495,6 +704,8 @@ static void free_elfcorebuf(void)
{
free_pages((unsigned long)elfcorebuf, get_order(elfcorebuf_sz_orig));
elfcorebuf = NULL;
+ vfree(elfnotes_buf);
+ elfnotes_buf = NULL;
}
static int __init parse_crash_elf64_headers(void)
@@ -538,14 +749,15 @@ static int __init parse_crash_elf64_headers(void)
goto fail;
/* Merge all PT_NOTE headers into one. */
- rc = merge_note_headers_elf64(elfcorebuf, &elfcorebuf_sz, &vmcore_list);
+ rc = merge_note_headers_elf64(elfcorebuf, &elfcorebuf_sz,
+ &elfnotes_buf, &elfnotes_sz);
if (rc)
goto fail;
rc = process_ptload_program_headers_elf64(elfcorebuf, elfcorebuf_sz,
- &vmcore_list);
+ elfnotes_sz, &vmcore_list);
if (rc)
goto fail;
- set_vmcore_list_offsets(elfcorebuf_sz, &vmcore_list);
+ set_vmcore_list_offsets(elfcorebuf_sz, elfnotes_sz, &vmcore_list);
return 0;
fail:
free_elfcorebuf();
@@ -592,14 +804,15 @@ static int __init parse_crash_elf32_headers(void)
goto fail;
/* Merge all PT_NOTE headers into one. */
- rc = merge_note_headers_elf32(elfcorebuf, &elfcorebuf_sz, &vmcore_list);
+ rc = merge_note_headers_elf32(elfcorebuf, &elfcorebuf_sz,
+ &elfnotes_buf, &elfnotes_sz);
if (rc)
goto fail;
rc = process_ptload_program_headers_elf32(elfcorebuf, elfcorebuf_sz,
- &vmcore_list);
+ elfnotes_sz, &vmcore_list);
if (rc)
goto fail;
- set_vmcore_list_offsets(elfcorebuf_sz, &vmcore_list);
+ set_vmcore_list_offsets(elfcorebuf_sz, elfnotes_sz, &vmcore_list);
return 0;
fail:
free_elfcorebuf();
Copyright © 1996 – 2023 Jason A. Donenfeld. All Rights Reverse Engineered.