[PATCH] i386 vDSO: use VM_ALWAYSDUMP
This patch fixes core dumps to include the vDSO vma, which is left out now.
It removes the special-case core writing macros, which were not doing the
right thing for the vDSO vma anyway. Instead, it uses VM_ALWAYSDUMP in the
vma; there is no need for the fixmap page to be installed. It handles the
CONFIG_COMPAT_VDSO case by making elf_core_dump use the fake vma from
get_gate_vma after real vmas in the same way the /proc/PID/maps code does.
This changes core dumps so they no longer include the non-PT_LOAD phdrs from
the vDSO. I made the change to add them in the first place, but in turned out
that nothing ever wanted them there since the advent of NT_AUXV. It's cleaner
to leave them out, and just let the phdrs inside the vDSO image speak for
themselves.
Signed-off-by: Roland McGrath <roland@redhat.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/fs/binfmt_elf.c b/fs/binfmt_elf.c
index 6fec8bf..90461f4 100644
--- a/fs/binfmt_elf.c
+++ b/fs/binfmt_elf.c
@@ -1428,6 +1428,32 @@
return sz;
}
+static struct vm_area_struct *first_vma(struct task_struct *tsk,
+ struct vm_area_struct *gate_vma)
+{
+ struct vm_area_struct *ret = tsk->mm->mmap;
+
+ if (ret)
+ return ret;
+ return gate_vma;
+}
+/*
+ * Helper function for iterating across a vma list. It ensures that the caller
+ * will visit `gate_vma' prior to terminating the search.
+ */
+static struct vm_area_struct *next_vma(struct vm_area_struct *this_vma,
+ struct vm_area_struct *gate_vma)
+{
+ struct vm_area_struct *ret;
+
+ ret = this_vma->vm_next;
+ if (ret)
+ return ret;
+ if (this_vma == gate_vma)
+ return NULL;
+ return gate_vma;
+}
+
/*
* Actual dumper
*
@@ -1443,7 +1469,7 @@
int segs;
size_t size = 0;
int i;
- struct vm_area_struct *vma;
+ struct vm_area_struct *vma, *gate_vma;
struct elfhdr *elf = NULL;
loff_t offset = 0, dataoff, foffset;
unsigned long limit = current->signal->rlim[RLIMIT_CORE].rlim_cur;
@@ -1529,6 +1555,10 @@
segs += ELF_CORE_EXTRA_PHDRS;
#endif
+ gate_vma = get_gate_vma(current);
+ if (gate_vma != NULL)
+ segs++;
+
/* Set up header */
fill_elf_header(elf, segs + 1); /* including notes section */
@@ -1596,7 +1626,8 @@
dataoff = offset = roundup(offset, ELF_EXEC_PAGESIZE);
/* Write program headers for segments dump */
- for (vma = current->mm->mmap; vma != NULL; vma = vma->vm_next) {
+ for (vma = first_vma(current, gate_vma); vma != NULL;
+ vma = next_vma(vma, gate_vma)) {
struct elf_phdr phdr;
size_t sz;
@@ -1645,7 +1676,8 @@
/* Align to page */
DUMP_SEEK(dataoff - foffset);
- for (vma = current->mm->mmap; vma != NULL; vma = vma->vm_next) {
+ for (vma = first_vma(current, gate_vma); vma != NULL;
+ vma = next_vma(vma, gate_vma)) {
unsigned long addr;
if (!maydump(vma))