lkml.org 
[lkml]   [2007]   [May]   [25]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
Date
From
Subject[PATCH 6/7] ELF-FDPIC: enable core dump filtering
This patch enables core dump filtering for ELF-FDPIC-formatted
core file.

Signed-off-by: Hidehiro Kawai <hidehiro.kawai.ez@hitachi.com>
---
fs/binfmt_elf_fdpic.c | 52 ++++++++++++++++++++++++++--------------
1 files changed, 35 insertions(+), 17 deletions(-)

Index: linux-2.6.22-rc2-mm1/fs/binfmt_elf_fdpic.c
===================================================================
--- linux-2.6.22-rc2-mm1.orig/fs/binfmt_elf_fdpic.c
+++ linux-2.6.22-rc2-mm1/fs/binfmt_elf_fdpic.c
@@ -1181,8 +1181,10 @@ static int dump_seek(struct file *file,
*
* I think we should skip something. But I am not sure how. H.J.
*/
-static int maydump(struct vm_area_struct *vma)
+static int maydump(struct vm_area_struct *vma, unsigned long mm_flags)
{
+ int dump_ok;
+
/* Do not dump I/O mapped devices or special mappings */
if (vma->vm_flags & (VM_IO | VM_RESERVED)) {
kdcore("%08lx: %08lx: no (IO)", vma->vm_start, vma->vm_flags);
@@ -1197,27 +1199,35 @@ static int maydump(struct vm_area_struct
return 0;
}

- /* Dump shared memory only if mapped from an anonymous file. */
+ /* By default, dump shared memory if mapped from an anonymous file. */
if (vma->vm_flags & VM_SHARED) {
if (vma->vm_file->f_path.dentry->d_inode->i_nlink == 0) {
- kdcore("%08lx: %08lx: no (share)", vma->vm_start, vma->vm_flags);
- return 1;
+ dump_ok = test_bit(MMF_DUMP_ANON_SHARED, &mm_flags);
+ kdcore("%08lx: %08lx: %s (share)", vma->vm_start,
+ vma->vm_flags, dump_ok ? "yes" : "no");
+ return dump_ok;
}

- kdcore("%08lx: %08lx: no (share)", vma->vm_start, vma->vm_flags);
- return 0;
+ dump_ok = test_bit(MMF_DUMP_MAPPED_SHARED, &mm_flags);
+ kdcore("%08lx: %08lx: %s (share)", vma->vm_start,
+ vma->vm_flags, dump_ok ? "yes" : "no");
+ return dump_ok;
}

#ifdef CONFIG_MMU
- /* If it hasn't been written to, don't write it out */
+ /* By default, if it hasn't been written to, don't write it out */
if (!vma->anon_vma) {
- kdcore("%08lx: %08lx: no (!anon)", vma->vm_start, vma->vm_flags);
- return 0;
+ dump_ok = test_bit(MMF_DUMP_MAPPED_PRIVATE, &mm_flags);
+ kdcore("%08lx: %08lx: %s (!anon)", vma->vm_start,
+ vma->vm_flags, dump_ok ? "yes" : "no");
+ return dump_ok;
}
#endif

- kdcore("%08lx: %08lx: yes", vma->vm_start, vma->vm_flags);
- return 1;
+ dump_ok = test_bit(MMF_DUMP_ANON_PRIVATE, &mm_flags);
+ kdcore("%08lx: %08lx: %s", vma->vm_start, vma->vm_flags,
+ dump_ok ? "yes" : "no");
+ return dump_ok;
}

/* An ELF note in memory */
@@ -1457,14 +1467,14 @@ static int elf_dump_thread_status(long s
*/
#ifdef CONFIG_MMU
static int elf_fdpic_dump_segments(struct file *file, size_t *size,
- unsigned long *limit)
+ unsigned long *limit, unsigned long mm_flags)
{
struct vm_area_struct *vma;

for (vma = current->mm->mmap; vma; vma = vma->vm_next) {
unsigned long addr;

- if (!maydump(vma))
+ if (!maydump(vma, mm_flags))
continue;

for (addr = vma->vm_start;
@@ -1512,14 +1522,14 @@ end_coredump:
*/
#ifndef CONFIG_MMU
static int elf_fdpic_dump_segments(struct file *file, size_t *size,
- unsigned long *limit)
+ unsigned long *limit, unsigned long mm_flags)
{
struct vm_list_struct *vml;

for (vml = current->mm->context.vmlist; vml; vml = vml->next) {
struct vm_area_struct *vma = vml->vma;

- if (!maydump(vma))
+ if (!maydump(vma, mm_flags))
continue;

if ((*size += PAGE_SIZE) > *limit)
@@ -1570,6 +1580,7 @@ static int elf_fdpic_core_dump(long sign
struct vm_list_struct *vml;
#endif
elf_addr_t *auxv;
+ unsigned long mm_flags;

/*
* We no longer stop all VM operations.
@@ -1707,6 +1718,13 @@ static int elf_fdpic_core_dump(long sign
/* Page-align dumped data */
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;
+
/* write program headers for segments dump */
for (
#ifdef CONFIG_MMU
@@ -1728,7 +1746,7 @@ static int elf_fdpic_core_dump(long sign
phdr.p_offset = offset;
phdr.p_vaddr = vma->vm_start;
phdr.p_paddr = 0;
- phdr.p_filesz = maydump(vma) ? sz : 0;
+ phdr.p_filesz = maydump(vma, mm_flags) ? sz : 0;
phdr.p_memsz = sz;
offset += phdr.p_filesz;
phdr.p_flags = vma->vm_flags & VM_READ ? PF_R : 0;
@@ -1762,7 +1780,7 @@ static int elf_fdpic_core_dump(long sign

DUMP_SEEK(dataoff);

- if (elf_fdpic_dump_segments(file, current->mm, &size, &limit) < 0)
+ if (elf_fdpic_dump_segments(file, &size, &limit, mm_flags) < 0)
goto end_coredump;

#ifdef ELF_CORE_WRITE_EXTRA_DATA

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/

\
 
 \ /
  Last update: 2007-05-25 15:15    [W:0.060 / U:0.148 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site