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selftests/bpf: Validate arch-specific argument registers limits

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Update uprobe_autoattach selftest to validate architecture-specific
argument passing through registers. Use new BPF_UPROBE and
BPF_URETPROBE, and construct both BPF-side and user-space side in such
a way that for different architectures we are fetching and checking
different number of arguments, matching architecture-specific limit of
how many registers are available for argument passing.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Tested-by: Alan Maguire <alan.maguire@oracle.com> # arm64
Tested-by: Ilya Leoshkevich <iii@linux.ibm.com> # s390x
Link: https://lore.kernel.org/bpf/20230120200914.3008030-12-andrii@kernel.org
This commit is contained in:
Andrii Nakryiko 2023-01-20 12:09:00 -08:00 committed by Daniel Borkmann
parent ac4afd6e6f
commit bc72742beb
3 changed files with 99 additions and 7 deletions
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33
tools/testing/selftests/bpf/prog_tests/uprobe_autoattach.c
View File

@ -3,18 +3,21 @@
#include <test_progs.h>
#include "test_uprobe_autoattach.skel.h"
#include "progs/bpf_misc.h"
/* uprobe attach point */
static noinline int autoattach_trigger_func(int arg)
static noinline int autoattach_trigger_func(int arg1, int arg2, int arg3,
int arg4, int arg5, int arg6,
int arg7, int arg8)
{
asm volatile ("");
return arg + 1;
return arg1 + arg2 + arg3 + arg4 + arg5 + arg6 + arg7 + arg8 + 1;
}
void test_uprobe_autoattach(void)
{
struct test_uprobe_autoattach *skel;
int trigger_val = 100, trigger_ret;
int trigger_ret;
size_t malloc_sz = 1;
char *mem;
@ -28,22 +31,42 @@ void test_uprobe_autoattach(void)
skel->bss->test_pid = getpid();
/* trigger & validate uprobe & uretprobe */
trigger_ret = autoattach_trigger_func(trigger_val);
trigger_ret = autoattach_trigger_func(1, 2, 3, 4, 5, 6, 7, 8);
skel->bss->test_pid = getpid();
/* trigger & validate shared library u[ret]probes attached by name */
mem = malloc(malloc_sz);
ASSERT_EQ(skel->bss->uprobe_byname_parm1, trigger_val, "check_uprobe_byname_parm1");
ASSERT_EQ(skel->bss->uprobe_byname_parm1, 1, "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_ret, trigger_ret, "check_uretprobe_byname_ret");
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");
ASSERT_EQ(skel->bss->a[0], 1, "arg1");
ASSERT_EQ(skel->bss->a[1], 2, "arg2");
ASSERT_EQ(skel->bss->a[2], 3, "arg3");
#if FUNC_REG_ARG_CNT > 3
ASSERT_EQ(skel->bss->a[3], 4, "arg4");
#endif
#if FUNC_REG_ARG_CNT > 4
ASSERT_EQ(skel->bss->a[4], 5, "arg5");
#endif
#if FUNC_REG_ARG_CNT > 5
ASSERT_EQ(skel->bss->a[5], 6, "arg6");
#endif
#if FUNC_REG_ARG_CNT > 6
ASSERT_EQ(skel->bss->a[6], 7, "arg7");
#endif
#if FUNC_REG_ARG_CNT > 7
ASSERT_EQ(skel->bss->a[7], 8, "arg8");
#endif
free(mem);
cleanup:
test_uprobe_autoattach__destroy(skel);

25
tools/testing/selftests/bpf/progs/bpf_misc.h
View File

@ -28,4 +28,29 @@
#define SYS_PREFIX "__se_"
#endif
/* How many arguments are passed to function in register */
#if defined(__TARGET_ARCH_x86) || defined(__x86_64__)
#define FUNC_REG_ARG_CNT 6
#elif defined(__i386__)
#define FUNC_REG_ARG_CNT 3
#elif defined(__TARGET_ARCH_s390) || defined(__s390x__)
#define FUNC_REG_ARG_CNT 5
#elif defined(__TARGET_ARCH_arm) || defined(__arm__)
#define FUNC_REG_ARG_CNT 4
#elif defined(__TARGET_ARCH_arm64) || defined(__aarch64__)
#define FUNC_REG_ARG_CNT 8
#elif defined(__TARGET_ARCH_mips) || defined(__mips__)
#define FUNC_REG_ARG_CNT 8
#elif defined(__TARGET_ARCH_powerpc) || defined(__powerpc__) || defined(__powerpc64__)
#define FUNC_REG_ARG_CNT 8
#elif defined(__TARGET_ARCH_sparc) || defined(__sparc__)
#define FUNC_REG_ARG_CNT 6
#elif defined(__TARGET_ARCH_riscv) || defined(__riscv__)
#define FUNC_REG_ARG_CNT 8
#else
/* default to 5 for others */
#define FUNC_REG_ARG_CNT 5
#endif
#endif

48
tools/testing/selftests/bpf/progs/test_uprobe_autoattach.c
View File

@ -6,10 +6,12 @@
#include <bpf/bpf_core_read.h>
#include <bpf/bpf_helpers.h>
#include <bpf/bpf_tracing.h>
#include "bpf_misc.h"
int uprobe_byname_parm1 = 0;
int uprobe_byname_ran = 0;
int uretprobe_byname_rc = 0;
int uretprobe_byname_ret = 0;
int uretprobe_byname_ran = 0;
size_t uprobe_byname2_parm1 = 0;
int uprobe_byname2_ran = 0;
@ -18,6 +20,8 @@ int uretprobe_byname2_ran = 0;
int test_pid;
int a[8];
/* This program cannot auto-attach, but that should not stop other
* programs from attaching.
*/
@ -28,18 +32,58 @@ int handle_uprobe_noautoattach(struct pt_regs *ctx)
}
SEC("uprobe//proc/self/exe:autoattach_trigger_func")
int handle_uprobe_byname(struct pt_regs *ctx)
int BPF_UPROBE(handle_uprobe_byname
, int arg1
, int arg2
, int arg3
#if FUNC_REG_ARG_CNT > 3
, int arg4
#endif
#if FUNC_REG_ARG_CNT > 4
, int arg5
#endif
#if FUNC_REG_ARG_CNT > 5
, int arg6
#endif
#if FUNC_REG_ARG_CNT > 6
, int arg7
#endif
#if FUNC_REG_ARG_CNT > 7
, int arg8
#endif
)
{
uprobe_byname_parm1 = PT_REGS_PARM1_CORE(ctx);
uprobe_byname_ran = 1;
a[0] = arg1;
a[1] = arg2;
a[2] = arg3;
#if FUNC_REG_ARG_CNT > 3
a[3] = arg4;
#endif
#if FUNC_REG_ARG_CNT > 4
a[4] = arg5;
#endif
#if FUNC_REG_ARG_CNT > 5
a[5] = arg6;
#endif
#if FUNC_REG_ARG_CNT > 6
a[6] = arg7;
#endif
#if FUNC_REG_ARG_CNT > 7
a[7] = arg8;
#endif
return 0;
}
SEC("uretprobe//proc/self/exe:autoattach_trigger_func")
int handle_uretprobe_byname(struct pt_regs *ctx)
int BPF_URETPROBE(handle_uretprobe_byname, int ret)
{
uretprobe_byname_rc = PT_REGS_RC_CORE(ctx);
uretprobe_byname_ret = ret;
uretprobe_byname_ran = 2;
return 0;
}