diff options
author | Vasily Gorbik <gor@linux.ibm.com> | 2019-11-25 14:07:40 +0100 |
---|---|---|
committer | Vasily Gorbik <gor@linux.ibm.com> | 2019-11-30 10:52:48 +0100 |
commit | de6921ccbd0fb2882a1f615a6d3cdfbdcd64532c (patch) | |
tree | 6c47a9ec2bea5d24977ba4951a234982b2ee5ff7 /arch | |
parent | e7409367abe54ad04868552b9d9fe4a56acc753d (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')
-rw-r--r-- | arch/s390/lib/test_unwind.c | 47 |
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; |