projects/linux·commit 24d5288f

coredump: elf_core_dump: skip kernel threads

24d5288f · Oleg Nesterov <[email protected]> · 2008-07-25 01:47:40 -07:00

linux_binfmt->core_dump() runs before the process does exit_aio(), this
means that we can hit the kernel thread which shares the same ->mm.
Afaics, nothing really bad can happen, but perhaps it makes sense to fix
this minor bug.

It is sad we have to iterate over all threads in system and use
GFP_ATOMIC.  Hopefully we can kill theses ugly do_each_thread()s, but this
needs some nontrivial changes in mm_struct and do_coredump.

Signed-off-by: Oleg Nesterov <[email protected]>
Cc: Roland McGrath <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
Commit
24d5288f06ed8b3a368eba967d587cdb012dfdf7
Parents
15b9f360

Changes

2 files changed · +9 −0

FileStatusAddDelContent
fs/binfmt_elf.cmodified+6−0View file
fs/binfmt_elf_fdpic.cmodified+3−0View file

fs/binfmt_elf.c

View file
diff --git a/fs/binfmt_elf.c b/fs/binfmt_elf.c
index 639d2d8..bad7d87 100644
--- a/fs/binfmt_elf.c
+++ b/fs/binfmt_elf.c
@@ -1520,6 +1520,9 @@ static int fill_note_info(struct elfhdr *elf, int phdrs,
rcu_read_lock();
do_each_thread(g, p)
if (p->mm == dump_task->mm) {
+ if (p->flags & PF_KTHREAD)
+ continue;
+
t = kzalloc(offsetof(struct elf_thread_core_info,
notes[info->thread_notes]),
GFP_ATOMIC);
@@ -1724,6 +1727,9 @@ static int fill_note_info(struct elfhdr *elf, int phdrs,
rcu_read_lock();
do_each_thread(g, p)
if (current->mm == p->mm && current != p) {
+ if (p->flags & PF_KTHREAD)
+ continue;
+
ets = kzalloc(sizeof(*ets), GFP_ATOMIC);
if (!ets) {
rcu_read_unlock();

fs/binfmt_elf_fdpic.c

View file
diff --git a/fs/binfmt_elf_fdpic.c b/fs/binfmt_elf_fdpic.c
index d051a32..71bcc4b 100644
--- a/fs/binfmt_elf_fdpic.c
+++ b/fs/binfmt_elf_fdpic.c
@@ -1626,6 +1626,9 @@ static int elf_fdpic_core_dump(long signr, struct pt_regs *regs,
rcu_read_lock();
do_each_thread(g,p)
if (current->mm == p->mm && current != p) {
+ if (p->flags & PF_KTHREAD)
+ continue;
+
tmp = kzalloc(sizeof(*tmp), GFP_ATOMIC);
if (!tmp) {
rcu_read_unlock();