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selftests/bpf: add tests for sleepable (uk)probes

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Add tests that ensure sleepable uprobe programs work correctly.
Add tests that ensure sleepable kprobe programs cannot attach.

Also add tests that attach both sleepable and non-sleepable
uprobe programs to the same location (i.e. same bpf_prog_array).

Acked-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Delyan Kratunov <delyank@fb.com>
Link: https://lore.kernel.org/r/c744e5bb7a5c0703f05444dc41f2522ba3579a48.1655248076.git.delyank@fb.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
This commit is contained in:
Delyan Kratunov 2022-06-14 23:10:44 +00:00 • committed by Alexei Starovoitov
parent c4cac71fc8
commit cb3f4a4a46
2 changed files with 108 additions and 1 deletions
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49
tools/testing/selftests/bpf/prog_tests/attach_probe.c
View file

@ -17,6 +17,14 @@ static void trigger_func2(void)
asm volatile ("");
}
/* attach point for byname sleepable uprobe */
static void trigger_func3(void)
{
asm volatile ("");
}
static char test_data[] = "test_data";
void test_attach_probe(void)
{
DECLARE_LIBBPF_OPTS(bpf_uprobe_opts, uprobe_opts);
@ -49,9 +57,17 @@ void test_attach_probe(void)
if (!ASSERT_GE(ref_ctr_offset, 0, "ref_ctr_offset"))
return;
skel = test_attach_probe__open_and_load();
skel = test_attach_probe__open();
if (!ASSERT_OK_PTR(skel, "skel_open"))
return;
/* sleepable kprobe test case needs flags set before loading */
if (!ASSERT_OK(bpf_program__set_flags(skel->progs.handle_kprobe_sleepable,
BPF_F_SLEEPABLE), "kprobe_sleepable_flags"))
goto cleanup;
if (!ASSERT_OK(test_attach_probe__load(skel), "skel_load"))
goto cleanup;
if (!ASSERT_OK_PTR(skel->bss, "check_bss"))
goto cleanup;
@ -151,6 +167,30 @@ void test_attach_probe(void)
if (!ASSERT_OK_PTR(skel->links.handle_uretprobe_byname2, "attach_uretprobe_byname2"))
goto cleanup;
/* sleepable kprobes should not attach successfully */
skel->links.handle_kprobe_sleepable = bpf_program__attach(skel->progs.handle_kprobe_sleepable);
if (!ASSERT_ERR_PTR(skel->links.handle_kprobe_sleepable, "attach_kprobe_sleepable"))
goto cleanup;
/* test sleepable uprobe and uretprobe variants */
skel->links.handle_uprobe_byname3_sleepable = bpf_program__attach(skel->progs.handle_uprobe_byname3_sleepable);
if (!ASSERT_OK_PTR(skel->links.handle_uprobe_byname3_sleepable, "attach_uprobe_byname3_sleepable"))
goto cleanup;
skel->links.handle_uprobe_byname3 = bpf_program__attach(skel->progs.handle_uprobe_byname3);
if (!ASSERT_OK_PTR(skel->links.handle_uprobe_byname3, "attach_uprobe_byname3"))
goto cleanup;
skel->links.handle_uretprobe_byname3_sleepable = bpf_program__attach(skel->progs.handle_uretprobe_byname3_sleepable);
if (!ASSERT_OK_PTR(skel->links.handle_uretprobe_byname3_sleepable, "attach_uretprobe_byname3_sleepable"))
goto cleanup;
skel->links.handle_uretprobe_byname3 = bpf_program__attach(skel->progs.handle_uretprobe_byname3);
if (!ASSERT_OK_PTR(skel->links.handle_uretprobe_byname3, "attach_uretprobe_byname3"))
goto cleanup;
skel->bss->user_ptr = test_data;
/* trigger & validate kprobe && kretprobe */
usleep(1);
@ -164,6 +204,9 @@ void test_attach_probe(void)
/* trigger & validate uprobe attached by name */
trigger_func2();
/* trigger & validate sleepable uprobe attached by name */
trigger_func3();
ASSERT_EQ(skel->bss->kprobe_res, 1, "check_kprobe_res");
ASSERT_EQ(skel->bss->kprobe2_res, 11, "check_kprobe_auto_res");
ASSERT_EQ(skel->bss->kretprobe_res, 2, "check_kretprobe_res");
@ -174,6 +217,10 @@ void test_attach_probe(void)
ASSERT_EQ(skel->bss->uretprobe_byname_res, 6, "check_uretprobe_byname_res");
ASSERT_EQ(skel->bss->uprobe_byname2_res, 7, "check_uprobe_byname2_res");
ASSERT_EQ(skel->bss->uretprobe_byname2_res, 8, "check_uretprobe_byname2_res");
ASSERT_EQ(skel->bss->uprobe_byname3_sleepable_res, 9, "check_uprobe_byname3_sleepable_res");
ASSERT_EQ(skel->bss->uprobe_byname3_res, 10, "check_uprobe_byname3_res");
ASSERT_EQ(skel->bss->uretprobe_byname3_sleepable_res, 11, "check_uretprobe_byname3_sleepable_res");
ASSERT_EQ(skel->bss->uretprobe_byname3_res, 12, "check_uretprobe_byname3_res");
cleanup:
test_attach_probe__destroy(skel);

60
tools/testing/selftests/bpf/progs/test_attach_probe.c
View file

@ -5,6 +5,7 @@
#include <linux/bpf.h>
#include <bpf/bpf_helpers.h>
#include <bpf/bpf_tracing.h>
#include <stdbool.h>
#include "bpf_misc.h"
int kprobe_res = 0;
@ -17,6 +18,11 @@ int uprobe_byname_res = 0;
int uretprobe_byname_res = 0;
int uprobe_byname2_res = 0;
int uretprobe_byname2_res = 0;
int uprobe_byname3_sleepable_res = 0;
int uprobe_byname3_res = 0;
int uretprobe_byname3_sleepable_res = 0;
int uretprobe_byname3_res = 0;
void *user_ptr = 0;
SEC("kprobe")
int handle_kprobe(struct pt_regs *ctx)
@ -32,6 +38,17 @@ int BPF_KPROBE(handle_kprobe_auto)
return 0;
}
/**
* This program will be manually made sleepable on the userspace side
* and should thus be unattachable.
*/
SEC("kprobe/" SYS_PREFIX "sys_nanosleep")
int handle_kprobe_sleepable(struct pt_regs *ctx)
{
kprobe_res = 2;
return 0;
}
SEC("kretprobe")
int handle_kretprobe(struct pt_regs *ctx)
{
@ -93,4 +110,47 @@ int handle_uretprobe_byname2(struct pt_regs *ctx)
return 0;
}
static __always_inline bool verify_sleepable_user_copy(void)
{
char data[9];
bpf_copy_from_user(data, sizeof(data), user_ptr);
return bpf_strncmp(data, sizeof(data), "test_data") == 0;
}
SEC("uprobe.s//proc/self/exe:trigger_func3")
int handle_uprobe_byname3_sleepable(struct pt_regs *ctx)
{
if (verify_sleepable_user_copy())
uprobe_byname3_sleepable_res = 9;
return 0;
}
/**
* same target as the uprobe.s above to force sleepable and non-sleepable
* programs in the same bpf_prog_array
*/
SEC("uprobe//proc/self/exe:trigger_func3")
int handle_uprobe_byname3(struct pt_regs *ctx)
{
uprobe_byname3_res = 10;
return 0;
}
SEC("uretprobe.s//proc/self/exe:trigger_func3")
int handle_uretprobe_byname3_sleepable(struct pt_regs *ctx)
{
if (verify_sleepable_user_copy())
uretprobe_byname3_sleepable_res = 11;
return 0;
}
SEC("uretprobe//proc/self/exe:trigger_func3")
int handle_uretprobe_byname3(struct pt_regs *ctx)
{
uretprobe_byname3_res = 12;
return 0;
}
char _license[] SEC("license") = "GPL";