xiaomi-sm8450/android_kernel_xiaomi_sm8450
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

s390: fix handling of runtime instrumentation psw bit

Browse Source 
Fix the following bugs:
- When returning from a signal the signal handler copies the saved psw mask
  from user space and uses parts of it. Especially it restores the RI bit
  unconditionally. If however the machine doesn't support RI, or RI is
  disabled for the task, the last lpswe instruction which returns to user
  space will generate a specification exception.
  To fix this check if the RI bit is allowed to be set and kill the task
  if not.
- In the compat mode signal handler code the RI bit of the psw mask gets
  propagated to the mask of the return psw: if user space enables RI in the
  signal handler, RI will also be enabled after the signal handler is
  finished.
  This is a different behaviour than with 64 bit tasks. So change this to
  match the 64 bit semantics, which restores the original RI bit value.
- Fix similar oddities within the ptrace code as well.

Reviewed-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
This commit is contained in:
Heiko Carstens
2013-10-16 09:58:01 +02:00
committed by Martin Schwidefsky
parent 4725c86055
commit 5ebf250dab
6 changed files with 37 additions and 15 deletions
Download Patch File Download Diff File Expand all files Collapse all files

2
arch/s390/include/uapi/asm/ptrace.h
View File

@@ -263,7 +263,7 @@ typedef struct
#define PSW_MASK_EA 0x0000000100000000UL
#define PSW_MASK_BA 0x0000000080000000UL
#define PSW_MASK_USER 0x0000FF8180000000UL
#define PSW_MASK_USER 0x0000FF0180000000UL
#define PSW_ADDR_AMODE 0x0000000000000000UL
#define PSW_ADDR_INSN 0xFFFFFFFFFFFFFFFFUL