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-rw-r--r--fs/binfmt_elf.c151
1 files changed, 90 insertions, 61 deletions
diff --git a/fs/binfmt_elf.c b/fs/binfmt_elf.c
index fd5b2ea5d29..535e763ab1a 100644
--- a/fs/binfmt_elf.c
+++ b/fs/binfmt_elf.c
@@ -31,6 +31,7 @@
#include <linux/random.h>
#include <linux/elf.h>
#include <linux/utsname.h>
+#include <linux/coredump.h>
#include <asm/uaccess.h>
#include <asm/param.h>
#include <asm/page.h>
@@ -1085,36 +1086,6 @@ out:
* Modelled on fs/exec.c:aout_core_dump()
* Jeremy Fitzhardinge <jeremy@sw.oz.au>
*/
-/*
- * These are the only things you should do on a core-file: use only these
- * functions to write out all the necessary info.
- */
-static int dump_write(struct file *file, const void *addr, int nr)
-{
- return file->f_op->write(file, addr, nr, &file->f_pos) == nr;
-}
-
-static int dump_seek(struct file *file, loff_t off)
-{
- if (file->f_op->llseek && file->f_op->llseek != no_llseek) {
- if (file->f_op->llseek(file, off, SEEK_CUR) < 0)
- return 0;
- } else {
- char *buf = (char *)get_zeroed_page(GFP_KERNEL);
- if (!buf)
- return 0;
- while (off > 0) {
- unsigned long n = off;
- if (n > PAGE_SIZE)
- n = PAGE_SIZE;
- if (!dump_write(file, buf, n))
- return 0;
- off -= n;
- }
- free_page((unsigned long)buf);
- }
- return 1;
-}
/*
* Decide what to dump of a segment, part, all or none.
@@ -1249,11 +1220,6 @@ static int writenote(struct memelfnote *men, struct file *file,
}
#undef DUMP_WRITE
-#define DUMP_WRITE(addr, nr) \
- if ((size += (nr)) > cprm->limit || \
- !dump_write(cprm->file, (addr), (nr))) \
- goto end_coredump;
-
static void fill_elf_header(struct elfhdr *elf, int segs,
u16 machine, u32 flags, u8 osabi)
{
@@ -1872,6 +1838,34 @@ static struct vm_area_struct *next_vma(struct vm_area_struct *this_vma,
return gate_vma;
}
+static void fill_extnum_info(struct elfhdr *elf, struct elf_shdr *shdr4extnum,
+ elf_addr_t e_shoff, int segs)
+{
+ elf->e_shoff = e_shoff;
+ elf->e_shentsize = sizeof(*shdr4extnum);
+ elf->e_shnum = 1;
+ elf->e_shstrndx = SHN_UNDEF;
+
+ memset(shdr4extnum, 0, sizeof(*shdr4extnum));
+
+ shdr4extnum->sh_type = SHT_NULL;
+ shdr4extnum->sh_size = elf->e_shnum;
+ shdr4extnum->sh_link = elf->e_shstrndx;
+ shdr4extnum->sh_info = segs;
+}
+
+static size_t elf_core_vma_data_size(struct vm_area_struct *gate_vma,
+ unsigned long mm_flags)
+{
+ struct vm_area_struct *vma;
+ size_t size = 0;
+
+ for (vma = first_vma(current, gate_vma); vma != NULL;
+ vma = next_vma(vma, gate_vma))
+ size += vma_dump_size(vma, mm_flags);
+ return size;
+}
+
/*
* Actual dumper
*
@@ -1888,8 +1882,11 @@ static int elf_core_dump(struct coredump_params *cprm)
struct vm_area_struct *vma, *gate_vma;
struct elfhdr *elf = NULL;
loff_t offset = 0, dataoff, foffset;
- unsigned long mm_flags;
struct elf_note_info info;
+ struct elf_phdr *phdr4note = NULL;
+ struct elf_shdr *shdr4extnum = NULL;
+ Elf_Half e_phnum;
+ elf_addr_t e_shoff;
/*
* We no longer stop all VM operations.
@@ -1912,20 +1909,25 @@ static int elf_core_dump(struct coredump_params *cprm)
* Please check DEFAULT_MAX_MAP_COUNT definition when you modify here.
*/
segs = current->mm->map_count;
-#ifdef ELF_CORE_EXTRA_PHDRS
- segs += ELF_CORE_EXTRA_PHDRS;
-#endif
+ segs += elf_core_extra_phdrs();
gate_vma = get_gate_vma(current);
if (gate_vma != NULL)
segs++;
+ /* for notes section */
+ segs++;
+
+ /* If segs > PN_XNUM(0xffff), then e_phnum overflows. To avoid
+ * this, kernel supports extended numbering. Have a look at
+ * include/linux/elf.h for further information. */
+ e_phnum = segs > PN_XNUM ? PN_XNUM : segs;
+
/*
* Collect all the non-memory information about the process for the
* notes. This also sets up the file header.
*/
- if (!fill_note_info(elf, segs + 1, /* including notes section */
- &info, cprm->signr, cprm->regs))
+ if (!fill_note_info(elf, e_phnum, &info, cprm->signr, cprm->regs))
goto cleanup;
has_dumped = 1;
@@ -1934,31 +1936,47 @@ static int elf_core_dump(struct coredump_params *cprm)
fs = get_fs();
set_fs(KERNEL_DS);
- DUMP_WRITE(elf, sizeof(*elf));
offset += sizeof(*elf); /* Elf header */
- offset += (segs + 1) * sizeof(struct elf_phdr); /* Program headers */
+ offset += segs * sizeof(struct elf_phdr); /* Program headers */
foffset = offset;
/* Write notes phdr entry */
{
- struct elf_phdr phdr;
size_t sz = get_note_info_size(&info);
sz += elf_coredump_extra_notes_size();
- fill_elf_note_phdr(&phdr, sz, offset);
+ phdr4note = kmalloc(sizeof(*phdr4note), GFP_KERNEL);
+ if (!phdr4note)
+ goto end_coredump;
+
+ fill_elf_note_phdr(phdr4note, sz, offset);
offset += sz;
- DUMP_WRITE(&phdr, sizeof(phdr));
}
dataoff = offset = roundup(offset, ELF_EXEC_PAGESIZE);
- /*
- * We must use the same mm->flags while dumping core to avoid
- * inconsistency between the program headers and bodies, otherwise an
- * unusable core file can be generated.
- */
- mm_flags = current->mm->flags;
+ offset += elf_core_vma_data_size(gate_vma, cprm->mm_flags);
+ offset += elf_core_extra_data_size();
+ e_shoff = offset;
+
+ if (e_phnum == PN_XNUM) {
+ shdr4extnum = kmalloc(sizeof(*shdr4extnum), GFP_KERNEL);
+ if (!shdr4extnum)
+ goto end_coredump;
+ fill_extnum_info(elf, shdr4extnum, e_shoff, segs);
+ }
+
+ offset = dataoff;
+
+ size += sizeof(*elf);
+ if (size > cprm->limit || !dump_write(cprm->file, elf, sizeof(*elf)))
+ goto end_coredump;
+
+ size += sizeof(*phdr4note);
+ if (size > cprm->limit
+ || !dump_write(cprm->file, phdr4note, sizeof(*phdr4note)))
+ goto end_coredump;
/* Write program headers for segments dump */
for (vma = first_vma(current, gate_vma); vma != NULL;
@@ -1969,7 +1987,7 @@ static int elf_core_dump(struct coredump_params *cprm)
phdr.p_offset = offset;
phdr.p_vaddr = vma->vm_start;
phdr.p_paddr = 0;
- phdr.p_filesz = vma_dump_size(vma, mm_flags);
+ phdr.p_filesz = vma_dump_size(vma, cprm->mm_flags);
phdr.p_memsz = vma->vm_end - vma->vm_start;
offset += phdr.p_filesz;
phdr.p_flags = vma->vm_flags & VM_READ ? PF_R : 0;
@@ -1979,12 +1997,14 @@ static int elf_core_dump(struct coredump_params *cprm)
phdr.p_flags |= PF_X;
phdr.p_align = ELF_EXEC_PAGESIZE;
- DUMP_WRITE(&phdr, sizeof(phdr));
+ size += sizeof(phdr);
+ if (size > cprm->limit
+ || !dump_write(cprm->file, &phdr, sizeof(phdr)))
+ goto end_coredump;
}
-#ifdef ELF_CORE_WRITE_EXTRA_PHDRS
- ELF_CORE_WRITE_EXTRA_PHDRS;
-#endif
+ if (!elf_core_write_extra_phdrs(cprm->file, offset, &size, cprm->limit))
+ goto end_coredump;
/* write out the notes section */
if (!write_note_info(&info, cprm->file, &foffset))
@@ -2002,7 +2022,7 @@ static int elf_core_dump(struct coredump_params *cprm)
unsigned long addr;
unsigned long end;
- end = vma->vm_start + vma_dump_size(vma, mm_flags);
+ end = vma->vm_start + vma_dump_size(vma, cprm->mm_flags);
for (addr = vma->vm_start; addr < end; addr += PAGE_SIZE) {
struct page *page;
@@ -2023,15 +2043,24 @@ static int elf_core_dump(struct coredump_params *cprm)
}
}
-#ifdef ELF_CORE_WRITE_EXTRA_DATA
- ELF_CORE_WRITE_EXTRA_DATA;
-#endif
+ if (!elf_core_write_extra_data(cprm->file, &size, cprm->limit))
+ goto end_coredump;
+
+ if (e_phnum == PN_XNUM) {
+ size += sizeof(*shdr4extnum);
+ if (size > cprm->limit
+ || !dump_write(cprm->file, shdr4extnum,
+ sizeof(*shdr4extnum)))
+ goto end_coredump;
+ }
end_coredump:
set_fs(fs);
cleanup:
free_note_info(&info);
+ kfree(shdr4extnum);
+ kfree(phdr4note);
kfree(elf);
out:
return has_dumped;
generated by cgit v1.2.3-70-g09d2 (git 2.46.0) at 2024-12-29 13:46:35 +0000