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authorMartin Schwidefsky <schwidefsky@de.ibm.com>2010-10-29 16:50:45 +0200
committerMartin Schwidefsky <sky@mschwide.boeblingen.de.ibm.com>2010-10-29 16:50:50 +0200
commit9ec2708053b647969bee862902872d44a5f9b439 (patch)
treea7ca43a31a656bac010fac46d11ff0fa23488ef1 /arch/s390/kernel
parentf2166bb117952404689f0dc42624ee0b54a66e5e (diff)
downloadlinux-linaro-android-9ec2708053b647969bee862902872d44a5f9b439.tar.gz
[S390] fix kprobes single stepping
Fix kprobes after git commit 1e54622e0403891b10f2105663e0f9dd595a1f17 broke it. The kprobe_handler is now called with interrupts in the state at the time of the breakpoint. The single step of the replaced instruction is done with interrupts off which makes it necessary to enable and disable the interupts in the kprobes code. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Diffstat (limited to 'arch/s390/kernel')
-rw-r--r--arch/s390/kernel/entry.S1
-rw-r--r--arch/s390/kernel/entry64.S1
-rw-r--r--arch/s390/kernel/kprobes.c9
3 files changed, 10 insertions, 1 deletions
diff --git a/arch/s390/kernel/entry.S b/arch/s390/kernel/entry.S
index 5efce720298..1ecc337fb67 100644
--- a/arch/s390/kernel/entry.S
+++ b/arch/s390/kernel/entry.S
@@ -557,6 +557,7 @@ pgm_svcper:
# per was called from kernel, must be kprobes
#
kernel_per:
+ REENABLE_IRQS
mvi SP_SVCNR(%r15),0xff # set trap indication to pgm check
mvi SP_SVCNR+1(%r15),0xff
la %r2,SP_PTREGS(%r15) # address of register-save area
diff --git a/arch/s390/kernel/entry64.S b/arch/s390/kernel/entry64.S
index a2be23922f4..8f3e802174d 100644
--- a/arch/s390/kernel/entry64.S
+++ b/arch/s390/kernel/entry64.S
@@ -568,6 +568,7 @@ pgm_svcper:
# per was called from kernel, must be kprobes
#
kernel_per:
+ REENABLE_IRQS
xc SP_SVCNR(2,%r15),SP_SVCNR(%r15) # clear svc number
la %r2,SP_PTREGS(%r15) # address of register-save area
brasl %r14,do_single_step
diff --git a/arch/s390/kernel/kprobes.c b/arch/s390/kernel/kprobes.c
index 2a3d2bf6f08..d60fc439851 100644
--- a/arch/s390/kernel/kprobes.c
+++ b/arch/s390/kernel/kprobes.c
@@ -316,6 +316,8 @@ static int __kprobes kprobe_handler(struct pt_regs *regs)
return 1;
ss_probe:
+ if (regs->psw.mask & (PSW_MASK_PER | PSW_MASK_IO))
+ local_irq_disable();
prepare_singlestep(p, regs);
kcb->kprobe_status = KPROBE_HIT_SS;
return 1;
@@ -463,6 +465,8 @@ static int __kprobes post_kprobe_handler(struct pt_regs *regs)
goto out;
}
reset_current_kprobe();
+ if (regs->psw.mask & (PSW_MASK_PER | PSW_MASK_IO))
+ local_irq_enable();
out:
preempt_enable_no_resched();
@@ -502,8 +506,11 @@ int __kprobes kprobe_fault_handler(struct pt_regs *regs, int trapnr)
regs->psw.mask |= kcb->kprobe_saved_imask;
if (kcb->kprobe_status == KPROBE_REENTER)
restore_previous_kprobe(kcb);
- else
+ else {
reset_current_kprobe();
+ if (regs->psw.mask & (PSW_MASK_PER | PSW_MASK_IO))
+ local_irq_enable();
+ }
preempt_enable_no_resched();
break;
case KPROBE_HIT_ACTIVE: