diff options
| author | Oleg Nesterov <oleg@redhat.com> | 2010-11-30 20:56:02 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@suse.de> | 2010-12-09 13:32:57 -0800 |
| commit | b7d121bbfa6b005a07cdb4bf2c81f9f983376dab (patch) | |
| tree | f664242277d9a21b9eba13e2f9a085b1a2ad36c1 /fs | |
| parent | 35cc70fc58822eff26b1c3f680244233f4fc09a5 (diff) | |
exec: copy-and-paste the fixes into compat_do_execve() paths
commit 114279be2120a916e8a04feeb2ac976a10016f2f upstream.
Note: this patch targets 2.6.37 and tries to be as simple as possible.
That is why it adds more copy-and-paste horror into fs/compat.c and
uglifies fs/exec.c, this will be cleanuped later.
compat_copy_strings() plays with bprm->vma/mm directly and thus has
two problems: it lacks the RLIMIT_STACK check and argv/envp memory
is not visible to oom killer.
Export acct_arg_size() and get_arg_page(), change compat_copy_strings()
to use get_arg_page(), change compat_do_execve() to do acct_arg_size(0)
as do_execve() does.
Add the fatal_signal_pending/cond_resched checks into compat_count() and
compat_copy_strings(), this matches the code in fs/exec.c and certainly
makes sense.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/compat.c | 28 | ||||
| -rw-r--r-- | fs/exec.c | 8 |
2 files changed, 19 insertions, 17 deletions
diff --git a/fs/compat.c b/fs/compat.c index 0644a154672b..8b41dcdcdc67 100644 --- a/fs/compat.c +++ b/fs/compat.c @@ -1378,6 +1378,10 @@ static int compat_count(compat_uptr_t __user *argv, int max) argv++; if (i++ >= max) return -E2BIG; + + if (fatal_signal_pending(current)) + return -ERESTARTNOHAND; + cond_resched(); } } return i; @@ -1419,6 +1423,12 @@ static int compat_copy_strings(int argc, compat_uptr_t __user *argv, while (len > 0) { int offset, bytes_to_copy; + if (fatal_signal_pending(current)) { + ret = -ERESTARTNOHAND; + goto out; + } + cond_resched(); + offset = pos % PAGE_SIZE; if (offset == 0) offset = PAGE_SIZE; @@ -1435,18 +1445,8 @@ static int compat_copy_strings(int argc, compat_uptr_t __user *argv, if (!kmapped_page || kpos != (pos & PAGE_MASK)) { struct page *page; -#ifdef CONFIG_STACK_GROWSUP - ret = expand_stack_downwards(bprm->vma, pos); - if (ret < 0) { - /* We've exceed the stack rlimit. */ - ret = -E2BIG; - goto out; - } -#endif - ret = get_user_pages(current, bprm->mm, pos, - 1, 1, 1, &page, NULL); - if (ret <= 0) { - /* We've exceed the stack rlimit. */ + page = get_arg_page(bprm, pos, 1); + if (!page) { ret = -E2BIG; goto out; } @@ -1567,8 +1567,10 @@ int compat_do_execve(char * filename, return retval; out: - if (bprm->mm) + if (bprm->mm) { + acct_arg_size(bprm, 0); mmput(bprm->mm); + } out_file: if (bprm->file) { diff --git a/fs/exec.c b/fs/exec.c index 70e80a4450de..d750cc0355a6 100644 --- a/fs/exec.c +++ b/fs/exec.c @@ -157,7 +157,7 @@ out: #ifdef CONFIG_MMU -static void acct_arg_size(struct linux_binprm *bprm, unsigned long pages) +void acct_arg_size(struct linux_binprm *bprm, unsigned long pages) { struct mm_struct *mm = current->mm; long diff = (long)(pages - bprm->vma_pages); @@ -176,7 +176,7 @@ static void acct_arg_size(struct linux_binprm *bprm, unsigned long pages) #endif } -static struct page *get_arg_page(struct linux_binprm *bprm, unsigned long pos, +struct page *get_arg_page(struct linux_binprm *bprm, unsigned long pos, int write) { struct page *page; @@ -290,11 +290,11 @@ static bool valid_arg_len(struct linux_binprm *bprm, long len) #else -static inline void acct_arg_size(struct linux_binprm *bprm, unsigned long pages) +void acct_arg_size(struct linux_binprm *bprm, unsigned long pages) { } -static struct page *get_arg_page(struct linux_binprm *bprm, unsigned long pos, +struct page *get_arg_page(struct linux_binprm *bprm, unsigned long pos, int write) { struct page *page; |