From 1717e248014c33a81d7a1cdc048c6b3bed7bb3f8 Mon Sep 17 00:00:00 2001 From: Alan Maguire Date: Wed, 6 Apr 2022 12:43:51 +0100 Subject: selftests/bpf: Uprobe tests should verify param/return values uprobe/uretprobe tests don't do any validation of arguments/return values, and without this we can't be sure we are attached to the right function, or that we are indeed attached to a uprobe or uretprobe. To fix this record argument and return value for auto-attached functions and ensure these match expectations. Also need to filter by pid to ensure we do not pick up stray malloc()s since auto-attach traces libc system-wide. Suggested-by: Andrii Nakryiko Signed-off-by: Alan Maguire Signed-off-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/1649245431-29956-4-git-send-email-alan.maguire@oracle.com --- .../selftests/bpf/prog_tests/uprobe_autoattach.c | 25 +++++++++---- .../selftests/bpf/progs/test_uprobe_autoattach.c | 43 ++++++++++++++++------ 2 files changed, 50 insertions(+), 18 deletions(-) (limited to 'tools') diff --git a/tools/testing/selftests/bpf/prog_tests/uprobe_autoattach.c b/tools/testing/selftests/bpf/prog_tests/uprobe_autoattach.c index 03b15d632be4..d6003dc8cc99 100644 --- a/tools/testing/selftests/bpf/prog_tests/uprobe_autoattach.c +++ b/tools/testing/selftests/bpf/prog_tests/uprobe_autoattach.c @@ -5,14 +5,17 @@ #include "test_uprobe_autoattach.skel.h" /* uprobe attach point */ -static void autoattach_trigger_func(void) +static noinline int autoattach_trigger_func(int arg) { asm volatile (""); + return arg + 1; } void test_uprobe_autoattach(void) { struct test_uprobe_autoattach *skel; + int trigger_val = 100, trigger_ret; + size_t malloc_sz = 1; char *mem; skel = test_uprobe_autoattach__open_and_load(); @@ -22,17 +25,25 @@ void test_uprobe_autoattach(void) if (!ASSERT_OK(test_uprobe_autoattach__attach(skel), "skel_attach")) goto cleanup; + skel->bss->test_pid = getpid(); + /* trigger & validate uprobe & uretprobe */ - autoattach_trigger_func(); + trigger_ret = autoattach_trigger_func(trigger_val); + + skel->bss->test_pid = getpid(); /* trigger & validate shared library u[ret]probes attached by name */ - mem = malloc(1); + mem = malloc(malloc_sz); free(mem); - ASSERT_EQ(skel->bss->uprobe_byname_res, 1, "check_uprobe_byname_res"); - ASSERT_EQ(skel->bss->uretprobe_byname_res, 2, "check_uretprobe_byname_res"); - ASSERT_EQ(skel->bss->uprobe_byname2_res, 3, "check_uprobe_byname2_res"); - ASSERT_EQ(skel->bss->uretprobe_byname2_res, 4, "check_uretprobe_byname2_res"); + ASSERT_EQ(skel->bss->uprobe_byname_parm1, trigger_val, "check_uprobe_byname_parm1"); + ASSERT_EQ(skel->bss->uprobe_byname_ran, 1, "check_uprobe_byname_ran"); + ASSERT_EQ(skel->bss->uretprobe_byname_rc, trigger_ret, "check_uretprobe_byname_rc"); + ASSERT_EQ(skel->bss->uretprobe_byname_ran, 2, "check_uretprobe_byname_ran"); + ASSERT_EQ(skel->bss->uprobe_byname2_parm1, malloc_sz, "check_uprobe_byname2_parm1"); + ASSERT_EQ(skel->bss->uprobe_byname2_ran, 3, "check_uprobe_byname2_ran"); + ASSERT_EQ(skel->bss->uretprobe_byname2_rc, mem, "check_uretprobe_byname2_rc"); + ASSERT_EQ(skel->bss->uretprobe_byname2_ran, 4, "check_uretprobe_byname2_ran"); cleanup: test_uprobe_autoattach__destroy(skel); } diff --git a/tools/testing/selftests/bpf/progs/test_uprobe_autoattach.c b/tools/testing/selftests/bpf/progs/test_uprobe_autoattach.c index b442fb5ef54b..ab75522e2eeb 100644 --- a/tools/testing/selftests/bpf/progs/test_uprobe_autoattach.c +++ b/tools/testing/selftests/bpf/progs/test_uprobe_autoattach.c @@ -1,15 +1,22 @@ // SPDX-License-Identifier: GPL-2.0 /* Copyright (c) 2022, Oracle and/or its affiliates. */ -#include -#include +#include "vmlinux.h" + +#include #include #include -int uprobe_byname_res = 0; -int uretprobe_byname_res = 0; -int uprobe_byname2_res = 0; -int uretprobe_byname2_res = 0; +int uprobe_byname_parm1 = 0; +int uprobe_byname_ran = 0; +int uretprobe_byname_rc = 0; +int uretprobe_byname_ran = 0; +size_t uprobe_byname2_parm1 = 0; +int uprobe_byname2_ran = 0; +char *uretprobe_byname2_rc = NULL; +int uretprobe_byname2_ran = 0; + +int test_pid; /* This program cannot auto-attach, but that should not stop other * programs from attaching. @@ -23,14 +30,16 @@ int handle_uprobe_noautoattach(struct pt_regs *ctx) SEC("uprobe//proc/self/exe:autoattach_trigger_func") int handle_uprobe_byname(struct pt_regs *ctx) { - uprobe_byname_res = 1; + uprobe_byname_parm1 = PT_REGS_PARM1_CORE(ctx); + uprobe_byname_ran = 1; return 0; } SEC("uretprobe//proc/self/exe:autoattach_trigger_func") int handle_uretprobe_byname(struct pt_regs *ctx) { - uretprobe_byname_res = 2; + uretprobe_byname_rc = PT_REGS_RC_CORE(ctx); + uretprobe_byname_ran = 2; return 0; } @@ -38,14 +47,26 @@ int handle_uretprobe_byname(struct pt_regs *ctx) SEC("uprobe/libc.so.6:malloc") int handle_uprobe_byname2(struct pt_regs *ctx) { - uprobe_byname2_res = 3; + int pid = bpf_get_current_pid_tgid() >> 32; + + /* ignore irrelevant invocations */ + if (test_pid != pid) + return 0; + uprobe_byname2_parm1 = PT_REGS_PARM1_CORE(ctx); + uprobe_byname2_ran = 3; return 0; } -SEC("uretprobe/libc.so.6:free") +SEC("uretprobe/libc.so.6:malloc") int handle_uretprobe_byname2(struct pt_regs *ctx) { - uretprobe_byname2_res = 4; + int pid = bpf_get_current_pid_tgid() >> 32; + + /* ignore irrelevant invocations */ + if (test_pid != pid) + return 0; + uretprobe_byname2_rc = (char *)PT_REGS_RC_CORE(ctx); + uretprobe_byname2_ran = 4; return 0; } -- cgit v1.2.3