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authorHeiko Carstens <heiko.carstens@de.ibm.com>2008-11-14 18:18:05 +0100
committerMartin Schwidefsky <schwidefsky@de.ibm.com>2008-11-14 18:18:53 +0100
commit50bec4ce5d36ebf96189dcc54e20c7fce4bf61bf (patch)
tree5f04e012e882ed15f9c7f1f45b0e9a27dd2656f5
parent632448f65001c4935ed0d3bb362017d773da2eca (diff)
downloadlinux-stericsson-50bec4ce5d36ebf96189dcc54e20c7fce4bf61bf.tar.gz
[S390] ftrace: fix kernel stack backchain walking
With CONFIG_IRQSOFF_TRACER the trace_hardirqs_off() function includes a call to __builtin_return_address(1). But we calltrace_hardirqs_off() from early entry code. There we have just a single stack frame. So this results in a kernel stack backchain walk that would walk beyond the kernel stack. Following the NULL terminated backchain this results in a lowcore read access. To fix this we simply call trace_hardirqs_off_caller() and pass the current instruction pointer. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
-rw-r--r--arch/s390/kernel/entry.S18
-rw-r--r--arch/s390/kernel/entry64.S11
2 files changed, 18 insertions, 11 deletions
diff --git a/arch/s390/kernel/entry.S b/arch/s390/kernel/entry.S
index 5f0c4fba87c3..08844fc24a2e 100644
--- a/arch/s390/kernel/entry.S
+++ b/arch/s390/kernel/entry.S
@@ -61,22 +61,25 @@ STACK_SIZE = 1 << STACK_SHIFT
#ifdef CONFIG_TRACE_IRQFLAGS
.macro TRACE_IRQS_ON
- l %r1,BASED(.Ltrace_irq_on)
+ basr %r2,%r0
+ l %r1,BASED(.Ltrace_irq_on_caller)
basr %r14,%r1
.endm
.macro TRACE_IRQS_OFF
- l %r1,BASED(.Ltrace_irq_off)
+ basr %r2,%r0
+ l %r1,BASED(.Ltrace_irq_off_caller)
basr %r14,%r1
.endm
.macro TRACE_IRQS_CHECK
+ basr %r2,%r0
tm SP_PSW(%r15),0x03 # irqs enabled?
jz 0f
- l %r1,BASED(.Ltrace_irq_on)
+ l %r1,BASED(.Ltrace_irq_on_caller)
basr %r14,%r1
j 1f
-0: l %r1,BASED(.Ltrace_irq_off)
+0: l %r1,BASED(.Ltrace_irq_off_caller)
basr %r14,%r1
1:
.endm
@@ -1113,9 +1116,10 @@ cleanup_io_leave_insn:
.Lschedtail: .long schedule_tail
.Lsysc_table: .long sys_call_table
#ifdef CONFIG_TRACE_IRQFLAGS
-.Ltrace_irq_on: .long trace_hardirqs_on
-.Ltrace_irq_off:
- .long trace_hardirqs_off
+.Ltrace_irq_on_caller:
+ .long trace_hardirqs_on_caller
+.Ltrace_irq_off_caller:
+ .long trace_hardirqs_off_caller
#endif
#ifdef CONFIG_LOCKDEP
.Llockdep_sys_exit:
diff --git a/arch/s390/kernel/entry64.S b/arch/s390/kernel/entry64.S
index d7ce150453f2..41aca06682aa 100644
--- a/arch/s390/kernel/entry64.S
+++ b/arch/s390/kernel/entry64.S
@@ -61,19 +61,22 @@ _TIF_WORK_INT = (_TIF_SIGPENDING | _TIF_NOTIFY_RESUME | _TIF_NEED_RESCHED | \
#ifdef CONFIG_TRACE_IRQFLAGS
.macro TRACE_IRQS_ON
- brasl %r14,trace_hardirqs_on
+ basr %r2,%r0
+ brasl %r14,trace_hardirqs_on_caller
.endm
.macro TRACE_IRQS_OFF
- brasl %r14,trace_hardirqs_off
+ basr %r2,%r0
+ brasl %r14,trace_hardirqs_off_caller
.endm
.macro TRACE_IRQS_CHECK
+ basr %r2,%r0
tm SP_PSW(%r15),0x03 # irqs enabled?
jz 0f
- brasl %r14,trace_hardirqs_on
+ brasl %r14,trace_hardirqs_on_caller
j 1f
-0: brasl %r14,trace_hardirqs_off
+0: brasl %r14,trace_hardirqs_off_caller
1:
.endm
#else