From 0b452520477efbe4370cb747572c3c63c7cb3176 Mon Sep 17 00:00:00 2001 From: Vasily Gorbik Date: Sat, 5 Mar 2022 18:57:44 +0100 Subject: [PATCH] s390/test_unwind: extend kretprobe test Verify unwinding from kretprobed function. Reviewed-by: Tobias Huschle Signed-off-by: Vasily Gorbik --- arch/s390/lib/test_unwind.c | 49 ++++++++++++++++++++++++++++++--------------- 1 file changed, 33 insertions(+), 16 deletions(-) diff --git a/arch/s390/lib/test_unwind.c b/arch/s390/lib/test_unwind.c index c01f028..468e1ce 100644 --- a/arch/s390/lib/test_unwind.c +++ b/arch/s390/lib/test_unwind.c @@ -132,36 +132,50 @@ static struct unwindme *unwindme; #define UWM_PGM 0x40 /* Unwind from program check handler */ #define UWM_KPROBE_ON_FTRACE 0x80 /* Unwind from kprobe handler called via ftrace. */ #define UWM_FTRACE 0x100 /* Unwind from ftrace handler. */ -#define UWM_KRETPROBE 0x200 /* Unwind kretprobe handlers. */ +#define UWM_KRETPROBE 0x200 /* Unwind through kretprobed function. */ +#define UWM_KRETPROBE_HANDLER 0x400 /* Unwind from kretprobe handler. */ -static __always_inline unsigned long get_psw_addr(void) +static __always_inline struct pt_regs fake_pt_regs(void) { - unsigned long psw_addr; + struct pt_regs regs; + + memset(®s, 0, sizeof(regs)); + regs.gprs[15] = current_stack_pointer(); asm volatile( "basr %[psw_addr],0\n" - : [psw_addr] "=d" (psw_addr)); - return psw_addr; + : [psw_addr] "=d" (regs.psw.addr)); + return regs; } static int kretprobe_ret_handler(struct kretprobe_instance *ri, struct pt_regs *regs) { struct unwindme *u = unwindme; + if (!(u->flags & UWM_KRETPROBE_HANDLER)) + return 0; + u->ret = test_unwind(NULL, (u->flags & UWM_REGS) ? regs : NULL, (u->flags & UWM_SP) ? u->sp : 0); return 0; } -static noinline notrace void test_unwind_kretprobed_func(void) +static noinline notrace int test_unwind_kretprobed_func(struct unwindme *u) { - asm volatile(" nop\n"); + struct pt_regs regs; + + if (!(u->flags & UWM_KRETPROBE)) + return 0; + + regs = fake_pt_regs(); + return test_unwind(NULL, (u->flags & UWM_REGS) ? ®s : NULL, + (u->flags & UWM_SP) ? u->sp : 0); } -static noinline void test_unwind_kretprobed_func_caller(void) +static noinline int test_unwind_kretprobed_func_caller(struct unwindme *u) { - test_unwind_kretprobed_func(); + return test_unwind_kretprobed_func(u); } static int test_unwind_kretprobe(struct unwindme *u) @@ -187,10 +201,12 @@ static int test_unwind_kretprobe(struct unwindme *u) return -EINVAL; } - test_unwind_kretprobed_func_caller(); + ret = test_unwind_kretprobed_func_caller(u); unregister_kretprobe(&my_kretprobe); unwindme = NULL; - return u->ret; + if (u->flags & UWM_KRETPROBE_HANDLER) + ret = u->ret; + return ret; } static int kprobe_pre_handler(struct kprobe *p, struct pt_regs *regs) @@ -304,16 +320,13 @@ static noinline int unwindme_func4(struct unwindme *u) return 0; } else if (u->flags & (UWM_PGM | UWM_KPROBE_ON_FTRACE)) { return test_unwind_kprobe(u); - } else if (u->flags & (UWM_KRETPROBE)) { + } else if (u->flags & (UWM_KRETPROBE | UWM_KRETPROBE_HANDLER)) { return test_unwind_kretprobe(u); } else if (u->flags & UWM_FTRACE) { return test_unwind_ftrace(u); } else { - struct pt_regs regs; + struct pt_regs regs = fake_pt_regs(); - memset(®s, 0, sizeof(regs)); - regs.psw.addr = get_psw_addr(); - regs.gprs[15] = current_stack_pointer(); return test_unwind(NULL, (u->flags & UWM_REGS) ? ®s : NULL, (u->flags & UWM_SP) ? u->sp : 0); @@ -452,6 +465,10 @@ static const struct test_params param_list[] = { TEST_WITH_FLAGS(UWM_KRETPROBE | UWM_SP), TEST_WITH_FLAGS(UWM_KRETPROBE | UWM_REGS), TEST_WITH_FLAGS(UWM_KRETPROBE | UWM_SP | UWM_REGS), + TEST_WITH_FLAGS(UWM_KRETPROBE_HANDLER), + TEST_WITH_FLAGS(UWM_KRETPROBE_HANDLER | UWM_SP), + TEST_WITH_FLAGS(UWM_KRETPROBE_HANDLER | UWM_REGS), + TEST_WITH_FLAGS(UWM_KRETPROBE_HANDLER | UWM_SP | UWM_REGS), }; /* -- 2.7.4