diff options
| author | Heiko Carstens <heiko.carstens@de.ibm.com> | 2013-10-16 09:58:01 +0200 |
|---|---|---|
| committer | Martin Schwidefsky <schwidefsky@de.ibm.com> | 2013-10-24 17:17:11 +0200 |
| commit | 5ebf250dabbae83ad875f0dda5a108503cf78f3b (patch) | |
| tree | 3b4cd4dd3540cbd9c9852293801b84c9b25146f8 /arch/s390/include/asm | |
| parent | 4725c86055f5bbdcdfe47199c0715881893a2c79 (diff) | |
s390: fix handling of runtime instrumentation psw bit
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>
Diffstat (limited to 'arch/s390/include/asm')
| -rw-r--r-- | arch/s390/include/asm/compat.h | 1 | ||||
| -rw-r--r-- | arch/s390/include/asm/processor.h | 3 |
2 files changed, 4 insertions, 0 deletions
diff --git a/arch/s390/include/asm/compat.h b/arch/s390/include/asm/compat.h index c1e7c646727c..7604cabf02c0 100644 --- a/arch/s390/include/asm/compat.h +++ b/arch/s390/include/asm/compat.h @@ -22,6 +22,7 @@ #define PSW32_MASK_ASC 0x0000C000UL #define PSW32_MASK_CC 0x00003000UL #define PSW32_MASK_PM 0x00000f00UL +#define PSW32_MASK_RI 0x00000080UL #define PSW32_MASK_USER 0x0000FF00UL diff --git a/arch/s390/include/asm/processor.h b/arch/s390/include/asm/processor.h index 3caaf6548ef5..a56e63483e0f 100644 --- a/arch/s390/include/asm/processor.h +++ b/arch/s390/include/asm/processor.h @@ -175,6 +175,9 @@ unsigned long get_wchan(struct task_struct *p); #define KSTK_EIP(tsk) (task_pt_regs(tsk)->psw.addr) #define KSTK_ESP(tsk) (task_pt_regs(tsk)->gprs[15]) +/* Has task runtime instrumentation enabled ? */ +#define is_ri_task(tsk) (!!(tsk)->thread.ri_cb) + static inline unsigned short stap(void) { unsigned short cpu_address; |