linux/arch/powerpc
Ravi Bangoria 9e1ba4f27f powerpc/kprobe: Fix oops when kprobed on 'stdu' instruction
If we set a kprobe on a 'stdu' instruction on powerpc64, we see a kernel
OOPS:

  Bad kernel stack pointer cd93c840 at c000000000009868
  Oops: Bad kernel stack pointer, sig: 6 [#1]
  ...
  GPR00: c000001fcd93cb30 00000000cd93c840 c0000000015c5e00 00000000cd93c840
  ...
  NIP [c000000000009868] resume_kernel+0x2c/0x58
  LR [c000000000006208] program_check_common+0x108/0x180

On a 64-bit system when the user probes on a 'stdu' instruction, the kernel does
not emulate actual store in emulate_step() because it may corrupt the exception
frame. So the kernel does the actual store operation in exception return code
i.e. resume_kernel().

resume_kernel() loads the saved stack pointer from memory using lwz, which only
loads the low 32-bits of the address, causing the kernel crash.

Fix this by loading the 64-bit value instead.

Fixes: be96f63375 ("powerpc: Split out instruction analysis part of emulate_step()")
Cc: stable@vger.kernel.org # v3.18+
Signed-off-by: Ravi Bangoria <ravi.bangoria@linux.vnet.ibm.com>
Reviewed-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Reviewed-by: Ananth N Mavinakayanahalli <ananth@linux.vnet.ibm.com>
[mpe: Change log massage, add stable tag]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-04-18 20:19:21 +10:00
..
boot powerpc/boot: Fix zImage TOC alignment 2017-03-08 10:39:32 +11:00
configs powerpc updates for 4.11 part 2 2017-03-01 10:10:16 -08:00
crypto powerpc/crypto/crc32c-vpmsum: Fix missing preempt_disable() 2017-04-07 21:12:58 +10:00
include powerpc: Wire up statx() syscall 2017-03-16 20:45:53 +11:00
kernel powerpc/kprobe: Fix oops when kprobed on 'stdu' instruction 2017-04-18 20:19:21 +10:00
kvm power/mm: update pte_write and pte_wrprotect to handle savedwrite 2017-03-09 17:01:09 -08:00
lib powerpc fixes for 4.11 #3 2017-03-07 10:46:10 -08:00
math-emu Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
mm powerpc/mm: Add missing global TLB invalidate if cxl is active 2017-04-05 22:13:37 +10:00
net powerpc updates for 4.11 part 1. 2017-02-22 10:30:38 -08:00
oprofile ktime: Cleanup ktime_set() usage 2016-12-25 17:21:22 +01:00
perf powerpc/perf: Handle sdar_mode for marked event in power9 2017-03-09 13:34:54 +11:00
platforms powerpc/pseries: Don't give a warning when HPT resizing isn't available 2017-03-17 16:10:58 +11:00
purgatory kexec, x86/purgatory: Unbreak it and clean it up 2017-03-10 20:55:09 +01:00
scripts powerpc/ftrace: Add Kconfig & Make glue for mprofile-kernel 2016-03-07 14:53:56 +11:00
sysdev axonram: Fix gendisk handling 2017-03-08 10:55:40 -07:00
xmon sched/headers: Prepare for new header dependencies before moving code to <linux/sched/signal.h> 2017-03-02 08:42:29 +01:00
Kconfig powerpc: Sort the selects under CONFIG_PPC 2017-03-06 23:05:42 +11:00
Kconfig.debug powerpc/xmon: Enable disassembly files (compilation changes) 2017-02-15 20:02:42 +11:00
Makefile powerpc: Fix compiling a BE kernel with a powerpc64le toolchain 2017-03-03 11:24:50 +11:00
relocs_check.sh powerpc/64: whitelist unresolved modversions CRCs 2016-09-22 14:46:31 +02:00