Minki/linux
1
0
Fork 1
mirror of https://github.com/torvalds/linux.git synced 2024-11-14 16:12:02 +00:00
Code Issues Packages Projects Releases Wiki Activity

powerpc, hw_breakpoint: Handle concurrent alignment interrupts

Browse Source 
If an alignment interrupt occurs on an instruction that is being
single-stepped, the alignment interrupt handler currently handles
the single-step condition by unconditionally sending a SIGTRAP to
the process.  Other synchronous interrupts that result in the
instruction being emulated do likewise.

With hw_breakpoint support, the hw_breakpoint code needs to be able
to intercept these single-step events as well as those where the
instruction executes normally and a trace interrupt happens.

Fix this by making emulate_single_step() use the existing
single_step_exception() function instead of calling _exception()
directly.  We then make single_step_exception() use the abstracted
clear_single_step() rather than clearing bits in the MSR image
directly so that emulate_single_step() will continue to work
correctly on Book 3E processors.

Signed-off-by: K.Prasad <prasad@linux.vnet.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
This commit is contained in:
K.Prasad 2010-06-15 11:35:31 +05:30 committed by Paul Mackerras
parent 5aae8a5370
commit 2538c2d08f
1 changed files with 3 additions and 5 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

8
arch/powerpc/kernel/traps.c
View File

@ -688,7 +688,7 @@ void RunModeException(struct pt_regs *regs)
void __kprobes single_step_exception(struct pt_regs *regs)
{
regs->msr &= ~(MSR_SE | MSR_BE); /* Turn off 'trace' bits */
clear_single_step(regs);
if (notify_die(DIE_SSTEP, "single_step", regs, 5,
5, SIGTRAP) == NOTIFY_STOP)
@ -707,10 +707,8 @@ void __kprobes single_step_exception(struct pt_regs *regs)
*/
static void emulate_single_step(struct pt_regs *regs)
{
if (single_stepping(regs)) {
clear_single_step(regs);
_exception(SIGTRAP, regs, TRAP_TRACE, 0);
}
if (single_stepping(regs))
single_step_exception(regs);
}
static inline int __parse_fpscr(unsigned long fpscr)