| Message ID | 20240502122313.1579719-6-jolsa@kernel.org (mailing list archive) |
|---|---|
| State | Superseded |
| Delegated to: | BPF |
| Headers | show |
| Series | uprobe: uretprobe speed up | expand |
On Thu, May 2, 2024 at 5:24 AM Jiri Olsa <jolsa@kernel.org> wrote: > > Adding test to verify that when called from outside of the > trampoline provided by kernel, the uretprobe syscall will cause > calling process to receive SIGILL signal and the attached bpf > program is not executed. > > Reviewed-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> > Signed-off-by: Jiri Olsa <jolsa@kernel.org> > --- > .../selftests/bpf/prog_tests/uprobe_syscall.c | 95 +++++++++++++++++++ > .../bpf/progs/uprobe_syscall_executed.c | 17 ++++ > 2 files changed, 112 insertions(+) > create mode 100644 tools/testing/selftests/bpf/progs/uprobe_syscall_executed.c > > diff --git a/tools/testing/selftests/bpf/prog_tests/uprobe_syscall.c b/tools/testing/selftests/bpf/prog_tests/uprobe_syscall.c > index 1a50cd35205d..c6fdb8c59ea3 100644 > --- a/tools/testing/selftests/bpf/prog_tests/uprobe_syscall.c > +++ b/tools/testing/selftests/bpf/prog_tests/uprobe_syscall.c > @@ -7,7 +7,10 @@ > #include <unistd.h> > #include <asm/ptrace.h> > #include <linux/compiler.h> > +#include <linux/stringify.h> > +#include <sys/wait.h> > #include "uprobe_syscall.skel.h" > +#include "uprobe_syscall_executed.skel.h" > > __naked unsigned long uretprobe_regs_trigger(void) > { > @@ -209,6 +212,91 @@ static void test_uretprobe_regs_change(void) > } > } > > +#ifndef __NR_uretprobe > +#define __NR_uretprobe 462 > +#endif > + > +__naked unsigned long uretprobe_syscall_call_1(void) > +{ > + /* > + * Pretend we are uretprobe trampoline to trigger the return > + * probe invocation in order to verify we get SIGILL. > + */ > + asm volatile ( > + "pushq %rax\n" > + "pushq %rcx\n" > + "pushq %r11\n" > + "movq $" __stringify(__NR_uretprobe) ", %rax\n" > + "syscall\n" > + "popq %r11\n" > + "popq %rcx\n" > + "retq\n" > + ); > +} > + > +__naked unsigned long uretprobe_syscall_call(void) > +{ > + asm volatile ( > + "call uretprobe_syscall_call_1\n" > + "retq\n" > + ); > +} > + > +static void test_uretprobe_syscall_call(void) > +{ > + LIBBPF_OPTS(bpf_uprobe_multi_opts, opts, > + .retprobe = true, > + ); > + struct uprobe_syscall_executed *skel; > + int pid, status, err, go[2], c; > + > + if (pipe(go)) > + return; very unlikely to fail, but still, ASSERT_OK() would be in order here But regardless: Acked-by: Andrii Nakryiko <andrii@kernel.org> [...]
diff --git a/tools/testing/selftests/bpf/prog_tests/uprobe_syscall.c b/tools/testing/selftests/bpf/prog_tests/uprobe_syscall.c index 1a50cd35205d..c6fdb8c59ea3 100644 --- a/tools/testing/selftests/bpf/prog_tests/uprobe_syscall.c +++ b/tools/testing/selftests/bpf/prog_tests/uprobe_syscall.c @@ -7,7 +7,10 @@ #include <unistd.h> #include <asm/ptrace.h> #include <linux/compiler.h> +#include <linux/stringify.h> +#include <sys/wait.h> #include "uprobe_syscall.skel.h" +#include "uprobe_syscall_executed.skel.h" __naked unsigned long uretprobe_regs_trigger(void) { @@ -209,6 +212,91 @@ static void test_uretprobe_regs_change(void) } } +#ifndef __NR_uretprobe +#define __NR_uretprobe 462 +#endif + +__naked unsigned long uretprobe_syscall_call_1(void) +{ + /* + * Pretend we are uretprobe trampoline to trigger the return + * probe invocation in order to verify we get SIGILL. + */ + asm volatile ( + "pushq %rax\n" + "pushq %rcx\n" + "pushq %r11\n" + "movq $" __stringify(__NR_uretprobe) ", %rax\n" + "syscall\n" + "popq %r11\n" + "popq %rcx\n" + "retq\n" + ); +} + +__naked unsigned long uretprobe_syscall_call(void) +{ + asm volatile ( + "call uretprobe_syscall_call_1\n" + "retq\n" + ); +} + +static void test_uretprobe_syscall_call(void) +{ + LIBBPF_OPTS(bpf_uprobe_multi_opts, opts, + .retprobe = true, + ); + struct uprobe_syscall_executed *skel; + int pid, status, err, go[2], c; + + if (pipe(go)) + return; + + skel = uprobe_syscall_executed__open_and_load(); + if (!ASSERT_OK_PTR(skel, "uprobe_syscall_executed__open_and_load")) + goto cleanup; + + pid = fork(); + if (!ASSERT_GE(pid, 0, "fork")) + goto cleanup; + + /* child */ + if (pid == 0) { + close(go[1]); + + /* wait for parent's kick */ + err = read(go[0], &c, 1); + if (err != 1) + exit(-1); + + uretprobe_syscall_call(); + _exit(0); + } + + skel->links.test = bpf_program__attach_uprobe_multi(skel->progs.test, pid, + "/proc/self/exe", + "uretprobe_syscall_call", &opts); + if (!ASSERT_OK_PTR(skel->links.test, "bpf_program__attach_uprobe_multi")) + goto cleanup; + + /* kick the child */ + write(go[1], &c, 1); + err = waitpid(pid, &status, 0); + ASSERT_EQ(err, pid, "waitpid"); + + /* verify the child got killed with SIGILL */ + ASSERT_EQ(WIFSIGNALED(status), 1, "WIFSIGNALED"); + ASSERT_EQ(WTERMSIG(status), SIGILL, "WTERMSIG"); + + /* verify the uretprobe program wasn't called */ + ASSERT_EQ(skel->bss->executed, 0, "executed"); + +cleanup: + uprobe_syscall_executed__destroy(skel); + close(go[1]); + close(go[0]); +} #else static void test_uretprobe_regs_equal(void) { @@ -219,6 +307,11 @@ static void test_uretprobe_regs_change(void) { test__skip(); } + +static void test_uretprobe_syscall_call(void) +{ + test__skip(); +} #endif void test_uprobe_syscall(void) @@ -227,4 +320,6 @@ void test_uprobe_syscall(void) test_uretprobe_regs_equal(); if (test__start_subtest("uretprobe_regs_change")) test_uretprobe_regs_change(); + if (test__start_subtest("uretprobe_syscall_call")) + test_uretprobe_syscall_call(); } diff --git a/tools/testing/selftests/bpf/progs/uprobe_syscall_executed.c b/tools/testing/selftests/bpf/progs/uprobe_syscall_executed.c new file mode 100644 index 000000000000..0d7f1a7db2e2 --- /dev/null +++ b/tools/testing/selftests/bpf/progs/uprobe_syscall_executed.c @@ -0,0 +1,17 @@ +// SPDX-License-Identifier: GPL-2.0 +#include "vmlinux.h" +#include <bpf/bpf_helpers.h> +#include <string.h> + +struct pt_regs regs; + +char _license[] SEC("license") = "GPL"; + +int executed = 0; + +SEC("uretprobe.multi") +int test(struct pt_regs *regs) +{ + executed = 1; + return 0; +}