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| author | Paul Menage <menage@google.com> | 2008-06-13 00:21:49 +0200 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2008-06-13 03:05:41 +0200 |
| commit | 6c826818ff55eae7702b778b5f8bdf765af3b2af (patch) | |
| tree | dab51aca0d7b86ccdc820894a96fad163f3fcb91 | |
| parent | pagemap: fix large pages in pagemap (diff) | |
| download | linux-6c826818ff55eae7702b778b5f8bdf765af3b2af.tar.xz linux-6c826818ff55eae7702b778b5f8bdf765af3b2af.zip | |
/proc/sysvipc/shm: fix 32-bit truncation of segment sizes
sysvipc_shm_proc_show() picks between format strings (based on the
expected maximum length of a SHM segment) in a way that prevents gcc from
performing format checks on the seq_printf() parameters. This hid two
format errors - shp->shm_segsz and shp->shm_nattach are both unsigned
long, but were being printed as unsigned int and signed int respectively.
This leads to 32-bit truncation of SHM segment sizes reported in
/proc/sysvipc/shm. (And for nattach, but that's less of a problem for
most users).
This patch makes the format string directly visible to gcc's format
specifier checker, and fixes the two broken format specifiers.
Signed-off-by: Paul Menage <menage@google.com>
Cc: Nadia Derbey <Nadia.Derbey@bull.net>
Cc: Manfred Spraul <manfred@colorfullife.com>
Cc: Pierre Peiffer <peifferp@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| -rw-r--r-- | ipc/shm.c | 16 |
1 files changed, 8 insertions, 8 deletions
diff --git a/ipc/shm.c b/ipc/shm.c index d05f6b564998..790240cd067f 100644 --- a/ipc/shm.c +++ b/ipc/shm.c @@ -1058,16 +1058,16 @@ asmlinkage long sys_shmdt(char __user *shmaddr) static int sysvipc_shm_proc_show(struct seq_file *s, void *it) { struct shmid_kernel *shp = it; - char *format; -#define SMALL_STRING "%10d %10d %4o %10u %5u %5u %5d %5u %5u %5u %5u %10lu %10lu %10lu\n" -#define BIG_STRING "%10d %10d %4o %21u %5u %5u %5d %5u %5u %5u %5u %10lu %10lu %10lu\n" +#if BITS_PER_LONG <= 32 +#define SIZE_SPEC "%10lu" +#else +#define SIZE_SPEC "%21lu" +#endif - if (sizeof(size_t) <= sizeof(int)) - format = SMALL_STRING; - else - format = BIG_STRING; - return seq_printf(s, format, + return seq_printf(s, + "%10d %10d %4o " SIZE_SPEC " %5u %5u " + "%5lu %5u %5u %5u %5u %10lu %10lu %10lu\n", shp->shm_perm.key, shp->shm_perm.id, shp->shm_perm.mode, |