[PATCH v2 05/20] vmcore: round up buffer size of ELF headers by PAGE_SIZE

HATAYAMA Daisuke
2013-03-05T07:05:25Z

To satisfy mmap() page-size boundary requirement, round up buffer size
of ELF headers by PAGE_SIZE. The resulting value becomes offset of ELF
note segments and it's assigned in unique PT_NOTE program header
entry.

Also, some part that assumes past ELF headers' size is replaced by
this new rounded-up value.

Signed-off-by: HATAYAMA Daisuke <d.hatayama@jp.fujitsu.com>
---

fs/proc/vmcore.c | 16 ++++++++--------
1 files changed, 8 insertions(+), 8 deletions(-)

diff --git a/fs/proc/vmcore.c b/fs/proc/vmcore.c
index 1b02d01..c511cf4 100644
--- a/fs/proc/vmcore.c
+++ b/fs/proc/vmcore.c
@@ -340,7 +340,7 @@ static int __init merge_note_headers_elf64(char *elfptr, size_t *elfsz,
phdr.p_flags = 0;
note_off = ehdr_ptr->e_phoff +
(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;
@@ -353,6 +353,7 @@ static int __init merge_note_headers_elf64(char *elfptr, size_t *elfsz,
/* Modify e_phnum to reflect merged headers. */
ehdr_ptr->e_phnum = ehdr_ptr->e_phnum - nr_ptnote + 1;

+ *elfsz = roundup(*elfsz, PAGE_SIZE);
out:
return 0;
}
@@ -449,7 +450,7 @@ static int __init merge_note_headers_elf32(char *elfptr, size_t *elfsz,
phdr.p_flags = 0;
note_off = ehdr_ptr->e_phoff +
(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;
@@ -462,6 +463,7 @@ static int __init merge_note_headers_elf32(char *elfptr, size_t *elfsz,
/* Modify e_phnum to reflect merged headers. */
ehdr_ptr->e_phnum = ehdr_ptr->e_phnum - nr_ptnote + 1;

+ *elfsz = roundup(*elfsz, PAGE_SIZE);
out:
return 0;
}
@@ -482,9 +484,8 @@ static int __init process_ptload_program_headers_elf64(char *elfptr,
phdr_ptr = (Elf64_Phdr*)(elfptr + ehdr_ptr->e_phoff); /* PT_NOTE hdr */

/* First program header is PT_NOTE header. */
- vmcore_off = ehdr_ptr->e_phoff +
- (ehdr_ptr->e_phnum) * sizeof(Elf64_Phdr) +
- phdr_ptr->p_memsz; /* Note sections */
+ vmcore_off = phdr_ptr->p_offset + roundup(phdr_ptr->p_memsz,
+ PAGE_SIZE);

for (i = 0; i < ehdr_ptr->e_phnum; i++, phdr_ptr++) {
if (phdr_ptr->p_type != PT_LOAD)
@@ -519,9 +520,8 @@ static int __init process_ptload_program_headers_elf32(char *elfptr,
phdr_ptr = (Elf32_Phdr*)(elfptr + ehdr_ptr->e_phoff); /* PT_NOTE hdr */

/* First program header is PT_NOTE header. */
- vmcore_off = ehdr_ptr->e_phoff +
- (ehdr_ptr->e_phnum) * sizeof(Elf32_Phdr) +
- phdr_ptr->p_memsz; /* Note sections */
+ vmcore_off = phdr_ptr->p_offset + roundup(phdr_ptr->p_memsz,
+ PAGE_SIZE);

for (i = 0; i < ehdr_ptr->e_phnum; i++, phdr_ptr++) {
if (phdr_ptr->p_type != PT_LOAD)