coredump masking: reimplementation of dumpable using two flags
This patch changes mm_struct.dumpable to a pair of bit flags.
set_dumpable() converts three-value dumpable to two flags and stores it into
lower two bits of mm_struct.flags instead of mm_struct.dumpable.
get_dumpable() behaves in the opposite way.
[akpm@linux-foundation.org: export set_dumpable]
Signed-off-by: Hidehiro Kawai <hidehiro.kawai.ez@hitachi.com>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: David Howells <dhowells@redhat.com>
Cc: Hugh Dickins <hugh@veritas.com>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/include/linux/sched.h b/include/linux/sched.h
index 731edaca..8dbd083 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -345,6 +345,13 @@
(mm)->hiwater_vm = (mm)->total_vm; \
} while (0)
+extern void set_dumpable(struct mm_struct *mm, int value);
+extern int get_dumpable(struct mm_struct *mm);
+
+/* mm flags */
+#define MMF_DUMPABLE 0 /* core dump is permitted */
+#define MMF_DUMP_SECURELY 1 /* core file is readable only by root */
+
struct mm_struct {
struct vm_area_struct * mmap; /* list of VMAs */
struct rb_root mm_rb;
@@ -402,7 +409,7 @@
unsigned int token_priority;
unsigned int last_interval;
- unsigned char dumpable:2;
+ unsigned long flags; /* Must use atomic bitops to access the bits */
/* coredumping support */
int core_waiters;