Adding test to check we can change common register values through uprobe program.
It's x86_64 specific test. Signed-off-by: Jiri Olsa <jo...@kernel.org> --- .../selftests/bpf/prog_tests/bpf_cookie.c | 1 + .../bpf/prog_tests/uprobe_multi_test.c | 107 ++++++++++++++++++ .../selftests/bpf/progs/uprobe_multi.c | 24 ++++ 3 files changed, 132 insertions(+) diff --git a/tools/testing/selftests/bpf/prog_tests/bpf_cookie.c b/tools/testing/selftests/bpf/prog_tests/bpf_cookie.c index 4a0670c056ba..2425fd26d1ea 100644 --- a/tools/testing/selftests/bpf/prog_tests/bpf_cookie.c +++ b/tools/testing/selftests/bpf/prog_tests/bpf_cookie.c @@ -6,6 +6,7 @@ #include <sys/syscall.h> #include <sys/mman.h> #include <unistd.h> +#include <asm/ptrace.h> #include <test_progs.h> #include <network_helpers.h> #include <bpf/btf.h> diff --git a/tools/testing/selftests/bpf/prog_tests/uprobe_multi_test.c b/tools/testing/selftests/bpf/prog_tests/uprobe_multi_test.c index 2ee17ef1dae2..012652b07399 100644 --- a/tools/testing/selftests/bpf/prog_tests/uprobe_multi_test.c +++ b/tools/testing/selftests/bpf/prog_tests/uprobe_multi_test.c @@ -2,6 +2,7 @@ #include <unistd.h> #include <pthread.h> +#include <asm/ptrace.h> #include <test_progs.h> #include "uprobe_multi.skel.h" #include "uprobe_multi_bench.skel.h" @@ -1340,6 +1341,111 @@ static void test_bench_attach_usdt(void) printf("%s: detached in %7.3lfs\n", __func__, detach_delta); } +#ifdef __x86_64__ +__naked __maybe_unused unsigned long uprobe_regs_change_trigger(void) +{ + asm volatile ( + "ret\n" + ); +} + +static __naked void uprobe_regs_change(struct pt_regs *before, struct pt_regs *after) +{ + asm volatile ( + "movq %r11, 48(%rdi)\n" + "movq %r10, 56(%rdi)\n" + "movq %r9, 64(%rdi)\n" + "movq %r8, 72(%rdi)\n" + "movq %rax, 80(%rdi)\n" + "movq %rcx, 88(%rdi)\n" + "movq %rdx, 96(%rdi)\n" + "movq %rsi, 104(%rdi)\n" + "movq %rdi, 112(%rdi)\n" + + /* save 2nd argument */ + "pushq %rsi\n" + "call uprobe_regs_change_trigger\n" + + /* save return value and load 2nd argument pointer to rax */ + "pushq %rax\n" + "movq 8(%rsp), %rax\n" + + "movq %r11, 48(%rax)\n" + "movq %r10, 56(%rax)\n" + "movq %r9, 64(%rax)\n" + "movq %r8, 72(%rax)\n" + "movq %rcx, 88(%rax)\n" + "movq %rdx, 96(%rax)\n" + "movq %rsi, 104(%rax)\n" + "movq %rdi, 112(%rax)\n" + + /* restore return value and 2nd argument */ + "pop %rax\n" + "pop %rsi\n" + + "movq %rax, 80(%rsi)\n" + "ret\n" + ); +} + +static void unique_regs_common(void) +{ + struct pt_regs before = {}, after = {}, expected = { + .rax = 0xc0ffe, + .rcx = 0xbad, + .rdx = 0xdead, + .r8 = 0x8, + .r9 = 0x9, + .r10 = 0x10, + .r11 = 0x11, + .rdi = 0x12, + .rsi = 0x13, + }; + LIBBPF_OPTS(bpf_uprobe_multi_opts, opts, + .unique = true, + ); + struct uprobe_multi *skel; + + skel = uprobe_multi__open_and_load(); + if (!ASSERT_OK_PTR(skel, "skel_open")) + return; + + skel->bss->pid = getpid(); + skel->bss->regs = expected; + + skel->links.uprobe_change_regs = bpf_program__attach_uprobe_multi( + skel->progs.uprobe_change_regs, + -1, "/proc/self/exe", + "uprobe_regs_change_trigger", + &opts); + if (!ASSERT_OK_PTR(skel->links.uprobe_change_regs, "bpf_program__attach_uprobe_multi")) + goto cleanup; + + uprobe_regs_change(&before, &after); + + ASSERT_EQ(after.rax, expected.rax, "ax"); + ASSERT_EQ(after.rcx, expected.rcx, "cx"); + ASSERT_EQ(after.rdx, expected.rdx, "dx"); + ASSERT_EQ(after.r8, expected.r8, "r8"); + ASSERT_EQ(after.r9, expected.r9, "r9"); + ASSERT_EQ(after.r10, expected.r10, "r10"); + ASSERT_EQ(after.r11, expected.r11, "r11"); + ASSERT_EQ(after.rdi, expected.rdi, "rdi"); + ASSERT_EQ(after.rsi, expected.rsi, "rsi"); + +cleanup: + uprobe_multi__destroy(skel); +} + +static void test_unique(void) +{ + if (test__start_subtest("unique_regs_common")) + unique_regs_common(); +} +#else +static void test_unique(void) { } +#endif + void test_uprobe_multi_test(void) { if (test__start_subtest("skel_api")) @@ -1372,5 +1478,6 @@ void test_uprobe_multi_test(void) test_session_cookie_skel_api(); if (test__start_subtest("session_cookie_recursive")) test_session_recursive_skel_api(); + test_unique(); RUN_TESTS(uprobe_multi_verifier); } diff --git a/tools/testing/selftests/bpf/progs/uprobe_multi.c b/tools/testing/selftests/bpf/progs/uprobe_multi.c index 44190efcdba2..f26f8b840985 100644 --- a/tools/testing/selftests/bpf/progs/uprobe_multi.c +++ b/tools/testing/selftests/bpf/progs/uprobe_multi.c @@ -141,3 +141,27 @@ int usdt_extra(struct pt_regs *ctx) /* we need this one just to mix PID-filtered and global USDT probes */ return 0; } + +#if defined(__TARGET_ARCH_x86) +struct pt_regs regs; + +SEC("uprobe.unique") +int BPF_UPROBE(uprobe_change_regs) +{ + pid_t cur_pid = bpf_get_current_pid_tgid() >> 32; + + if (cur_pid != pid) + return 0; + + ctx->ax = regs.ax; + ctx->cx = regs.cx; + ctx->dx = regs.dx; + ctx->r8 = regs.r8; + ctx->r9 = regs.r9; + ctx->r10 = regs.r10; + ctx->r11 = regs.r11; + ctx->di = regs.di; + ctx->si = regs.si; + return 0; +} +#endif -- 2.51.0