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authorVasily Gorbik <gor@linux.ibm.com>2019-11-25 14:07:40 +0100
committerVasily Gorbik <gor@linux.ibm.com>2019-11-30 10:52:48 +0100
commitde6921ccbd0fb2882a1f615a6d3cdfbdcd64532c (patch)
tree6c47a9ec2bea5d24977ba4951a234982b2ee5ff7 /arch/s390/lib
parente7409367abe54ad04868552b9d9fe4a56acc753d (diff)
s390/test_unwind: add program check context tests
Add unwinding from program check handler tests. Unwinder should be able to unwind through pt_regs stored by program check handler on task stack. Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Diffstat (limited to 'arch/s390/lib')
-rw-r--r--arch/s390/lib/test_unwind.c47
1 files changed, 47 insertions, 0 deletions
diff --git a/arch/s390/lib/test_unwind.c b/arch/s390/lib/test_unwind.c
index 72fa745281f0..bda7ac0ddd29 100644
--- a/arch/s390/lib/test_unwind.c
+++ b/arch/s390/lib/test_unwind.c
@@ -10,6 +10,7 @@
#include <linux/kthread.h>
#include <linux/module.h>
#include <linux/string.h>
+#include <linux/kprobes.h>
#include <linux/wait.h>
#include <asm/irq.h>
#include <asm/delay.h>
@@ -119,6 +120,7 @@ static struct unwindme *unwindme;
#define UWM_CALLER 0x8 /* Unwind starting from caller. */
#define UWM_SWITCH_STACK 0x10 /* Use CALL_ON_STACK. */
#define UWM_IRQ 0x20 /* Unwind from irq context. */
+#define UWM_PGM 0x40 /* Unwind from program check handler. */
static __always_inline unsigned long get_psw_addr(void)
{
@@ -130,6 +132,17 @@ static __always_inline unsigned long get_psw_addr(void)
return psw_addr;
}
+#ifdef CONFIG_KPROBES
+static int pgm_pre_handler(struct kprobe *p, struct pt_regs *regs)
+{
+ struct unwindme *u = unwindme;
+
+ u->ret = test_unwind(NULL, (u->flags & UWM_REGS) ? regs : NULL,
+ (u->flags & UWM_SP) ? u->sp : 0);
+ return 0;
+}
+#endif
+
/* This function may or may not appear in the backtrace. */
static noinline int unwindme_func4(struct unwindme *u)
{
@@ -140,6 +153,34 @@ static noinline int unwindme_func4(struct unwindme *u)
wait_event(u->task_wq, kthread_should_park());
kthread_parkme();
return 0;
+#ifdef CONFIG_KPROBES
+ } else if (u->flags & UWM_PGM) {
+ struct kprobe kp;
+ int ret;
+
+ unwindme = u;
+ memset(&kp, 0, sizeof(kp));
+ kp.symbol_name = "do_report_trap";
+ kp.pre_handler = pgm_pre_handler;
+ ret = register_kprobe(&kp);
+ if (ret < 0) {
+ pr_err("register_kprobe failed %d\n", ret);
+ return -EINVAL;
+ }
+
+ /*
+ * trigger specification exception
+ */
+ asm volatile(
+ " mvcl %%r1,%%r1\n"
+ "0: nopr %%r7\n"
+ EX_TABLE(0b, 0b)
+ :);
+
+ unregister_kprobe(&kp);
+ unwindme = NULL;
+ return u->ret;
+#endif
} else {
struct pt_regs regs;
@@ -286,6 +327,12 @@ do { \
TEST(UWM_IRQ | UWM_CALLER | UWM_SP);
TEST(UWM_IRQ | UWM_CALLER | UWM_SP | UWM_REGS);
TEST(UWM_IRQ | UWM_CALLER | UWM_SP | UWM_REGS | UWM_SWITCH_STACK);
+#ifdef CONFIG_KPROBES
+ TEST(UWM_PGM);
+ TEST(UWM_PGM | UWM_SP);
+ TEST(UWM_PGM | UWM_REGS);
+ TEST(UWM_PGM | UWM_SP | UWM_REGS);
+#endif
#undef TEST
return ret;