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5f01c98859
linux/arch/x86/platform
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Jiri Slaby 5f01c98859 x86/dumpstack: Fix printk_address for direct addresses 
Consider a kernel crash in a module, simulated the following way:

 static int my_init(void)
 {
         char *map = (void *)0x5;
         *map = 3;
         return 0;
 }
 module_init(my_init);

When we turn off FRAME_POINTERs, the very first instruction in
that function causes a BUG. The problem is that we print IP in
the BUG report using %pB (from printk_address). And %pB
decrements the pointer by one to fix printing addresses of
functions with tail calls.

This was added in commit 71f9e59800 ("x86, dumpstack: Use
%pB format specifier for stack trace") to fix the call stack
printouts.

So instead of correct output:

  BUG: unable to handle kernel NULL pointer dereference at 0000000000000005
  IP: [<ffffffffa01ac000>] my_init+0x0/0x10 [pb173]

We get:

  BUG: unable to handle kernel NULL pointer dereference at 0000000000000005
  IP: [<ffffffffa0152000>] 0xffffffffa0151fff

To fix that, we use %pS only for stack addresses printouts (via
newly added printk_stack_address) and %pB for regs->ip (via
printk_address). I.e. we revert to the old behaviour for all
except call stacks. And since from all those reliable is 1, we
remove that parameter from printk_address.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Cc: Namhyung Kim <namhyung@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: joe@perches.com
Cc: jirislaby@gmail.com
Link: http://lkml.kernel.org/r/1382706418-8435-1-git-send-email-jslaby@suse.cz
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-11-12 21:06:06 +01:00
..
ce4100 arch/x86/platform/ce4100/ce4100.c: include reboot.h 2013-07-31 14:41:02 -07:00
efi Merge branch 'x86-efi-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2013-11-12 10:48:30 +09:00
geode x86/geode: Fix incorrect placement of __initdata tag 2013-10-01 13:21:27 +02:00
goldfish goldfish: platform device for x86 2013-01-21 12:09:19 -08:00
intel-mid x86, intel-mid: Do not re-introduce usage of obsolete __cpuinit 2013-11-07 10:44:03 -08:00
iris arch/x86/platform/iris/iris.c: register a platform device and a platform driver 2012-12-18 15:02:11 -08:00
olpc x86/olpc/xo1/sci: Don't call input_free_device() after input_unregister_device() 2013-04-24 08:44:47 +02:00
scx200 X86: drivers: remove __dev* attributes. 2013-01-03 15:57:04 -08:00
sfi x86: Convert a few mistaken __cpuinit annotations to __init 2013-01-24 17:12:19 +01:00
ts5500 x86: Add TS-5500 platform support 2013-01-25 19:40:23 +01:00
uv x86/dumpstack: Fix printk_address for direct addresses 2013-11-12 21:06:06 +01:00
visws x86/apic: Fix typo EIO_ACK -> EOI_ACK and document it 2012-05-18 09:46:07 +02:00
Makefile intel_mid: Renamed *mrst* to *intel_mid* 2013-10-17 16:40:36 -07:00