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authorLinus Torvalds <torvalds@linux-foundation.org>2009-01-03 11:46:17 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2009-01-03 11:46:17 -0800
commitd97106ab53f812910a62d18afb9dbe882819c1ba (patch)
treeedd1a2c287b7d98ee7b62e7ea6457c8a10abe016
parent3bfacef412b4bc993a8992217e50f1245f2fd3a6 (diff)
Make %p print '(null)' for NULL pointers
Before, when we only ever printed out the pointer value itself, a NULL pointer would never cause issues and might as well be printed out as just its numeric value. However, with the extended %p formats, especially %pR, we might validly want to print out resources for debugging. And sometimes they don't even exist, and the resource pointer is just NULL. Print it out as such, rather than oopsing. This is a more generic version of a patch done by Trent Piepho (catching all %p cases rather than just %pR, and using "(null)" instead of "[NULL]" to match glibc). Requested-by: Trent Piepho <xyzzy@speakeasy.org> Acked-by: Harvey Harrison <harvey.harrison@gmail.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--lib/vsprintf.c3
1 files changed, 3 insertions, 0 deletions
diff --git a/lib/vsprintf.c b/lib/vsprintf.c
index 3b777025d876..98d632277ca8 100644
--- a/lib/vsprintf.c
+++ b/lib/vsprintf.c
@@ -661,6 +661,9 @@ static char *ip4_addr_string(char *buf, char *end, u8 *addr, int field_width,
*/
static char *pointer(const char *fmt, char *buf, char *end, void *ptr, int field_width, int precision, int flags)
{
+ if (!ptr)
+ return string(buf, end, "(null)", field_width, precision, flags);
+
switch (*fmt) {
case 'F':
ptr = dereference_function_descriptor(ptr);