commit: 3715c5309f6d175c3053672b73fd4f73be16fd07
From: Dan Rosenberg <[email protected]>
Date: Mon, 30 Jul 2012 14:40:26 -0700
Subject: lib/vsprintf.c: kptr_restrict: fix pK-error in SysRq show-all-timers(Q)

When using ALT+SysRq+Q all the pointers are replaced with "pK-error" like
this:

        [23153.208033]   .base:               pK-error

with echo h > /proc/sysrq-trigger it works:

        [23107.776363]   .base:       ffff88023e60d540

The intent behind this behavior was to return "pK-error" in cases where
the %pK format specifier was used in interrupt context, because the
CAP_SYSLOG check wouldn't be meaningful.  Clearly this should only apply
when kptr_restrict is actually enabled though.

Reported-by: Stevie Trujillo <[email protected]>
Signed-off-by: Dan Rosenberg <[email protected]>
Cc: <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
---
 lib/vsprintf.c |    3 ++-
 1 files changed, 2 insertions(+), 1 deletions(-)

diff --git a/lib/vsprintf.c b/lib/vsprintf.c
index a0b5f15..225aa68 100644
--- a/lib/vsprintf.c
+++ b/lib/vsprintf.c
@@ -1045,7 +1045,8 @@ char *pointer(const char *fmt, char *buf, char *end, void 
*ptr,
                 * %pK cannot be used in IRQ context because its test
                 * for CAP_SYSLOG would be meaningless.
                 */
-               if (in_irq() || in_serving_softirq() || in_nmi()) {
+               if (kptr_restrict && (in_irq() || in_serving_softirq() ||
+                                     in_nmi())) {
                        if (spec.field_width == -1)
                                spec.field_width = default_width;
                        return string(buf, end, "pK-error", spec);
-- 
1.7.3.4
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