diff mbox series

[bpf-next,v3,1/6] samples/bpf: use kyscall instead of kprobe in syscall tracing program

Message ID 20221224071527.2292-2-danieltimlee@gmail.com (mailing list archive)
State Accepted
Commit 1d0c5f6f3d1387ec9c3a379fb232c078f5838d55
Delegated to: BPF
Headers show
Series samples/bpf: enhance syscall tracing program | expand

Checks

Context Check Description
netdev/tree_selection success Clearly marked for bpf-next, async
netdev/fixes_present success Fixes tag not required for -next series
netdev/subject_prefix success Link
netdev/cover_letter success Series has a cover letter
netdev/patch_count success Link
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 0 this patch: 0
netdev/cc_maintainers warning 1 maintainers not CCed: andrii@kernel.org
netdev/build_clang success Errors and warnings before: 0 this patch: 0
netdev/module_param success Was 0 now: 0
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/check_selftest success No net selftest shell script
netdev/verify_fixes success No Fixes tag
netdev/build_allmodconfig_warn success Errors and warnings before: 0 this patch: 0
netdev/checkpatch warning WARNING: added, moved or deleted file(s), does MAINTAINERS need updating?
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0
bpf/vmtest-bpf-next-PR success PR summary
bpf/vmtest-bpf-next-VM_Test-31 success Logs for test_progs_parallel on s390x with gcc
bpf/vmtest-bpf-next-VM_Test-16 success Logs for test_progs on s390x with gcc
bpf/vmtest-bpf-next-VM_Test-21 success Logs for test_progs_no_alu32 on s390x with gcc
bpf/vmtest-bpf-next-VM_Test-11 success Logs for test_maps on s390x with gcc
bpf/vmtest-bpf-next-VM_Test-1 success Logs for ShellCheck
bpf/vmtest-bpf-next-VM_Test-7 success Logs for llvm-toolchain
bpf/vmtest-bpf-next-VM_Test-8 success Logs for set-matrix
bpf/vmtest-bpf-next-VM_Test-2 success Logs for build for aarch64 with gcc
bpf/vmtest-bpf-next-VM_Test-3 success Logs for build for aarch64 with llvm-16
bpf/vmtest-bpf-next-VM_Test-5 success Logs for build for x86_64 with gcc
bpf/vmtest-bpf-next-VM_Test-6 success Logs for build for x86_64 with llvm-16
bpf/vmtest-bpf-next-VM_Test-4 success Logs for build for s390x with gcc
bpf/vmtest-bpf-next-VM_Test-9 success Logs for test_maps on aarch64 with gcc
bpf/vmtest-bpf-next-VM_Test-12 success Logs for test_maps on x86_64 with gcc
bpf/vmtest-bpf-next-VM_Test-13 success Logs for test_maps on x86_64 with llvm-16
bpf/vmtest-bpf-next-VM_Test-14 success Logs for test_progs on aarch64 with gcc
bpf/vmtest-bpf-next-VM_Test-17 success Logs for test_progs on x86_64 with gcc
bpf/vmtest-bpf-next-VM_Test-18 success Logs for test_progs on x86_64 with llvm-16
bpf/vmtest-bpf-next-VM_Test-22 success Logs for test_progs_no_alu32 on x86_64 with gcc
bpf/vmtest-bpf-next-VM_Test-23 success Logs for test_progs_no_alu32 on x86_64 with llvm-16
bpf/vmtest-bpf-next-VM_Test-24 success Logs for test_progs_no_alu32_parallel on aarch64 with gcc
bpf/vmtest-bpf-next-VM_Test-27 success Logs for test_progs_no_alu32_parallel on x86_64 with gcc
bpf/vmtest-bpf-next-VM_Test-28 success Logs for test_progs_no_alu32_parallel on x86_64 with llvm-16
bpf/vmtest-bpf-next-VM_Test-29 success Logs for test_progs_parallel on aarch64 with gcc
bpf/vmtest-bpf-next-VM_Test-30 success Logs for test_progs_parallel on aarch64 with llvm-16
bpf/vmtest-bpf-next-VM_Test-32 success Logs for test_progs_parallel on x86_64 with gcc
bpf/vmtest-bpf-next-VM_Test-33 success Logs for test_progs_parallel on x86_64 with llvm-16
bpf/vmtest-bpf-next-VM_Test-34 success Logs for test_verifier on aarch64 with gcc
bpf/vmtest-bpf-next-VM_Test-35 success Logs for test_verifier on aarch64 with llvm-16
bpf/vmtest-bpf-next-VM_Test-37 success Logs for test_verifier on x86_64 with gcc
bpf/vmtest-bpf-next-VM_Test-38 success Logs for test_verifier on x86_64 with llvm-16
bpf/vmtest-bpf-next-VM_Test-10 success Logs for test_maps on aarch64 with llvm-16
bpf/vmtest-bpf-next-VM_Test-15 success Logs for test_progs on aarch64 with llvm-16
bpf/vmtest-bpf-next-VM_Test-19 success Logs for test_progs_no_alu32 on aarch64 with gcc
bpf/vmtest-bpf-next-VM_Test-20 success Logs for test_progs_no_alu32 on aarch64 with llvm-16
bpf/vmtest-bpf-next-VM_Test-25 success Logs for test_progs_no_alu32_parallel on aarch64 with llvm-16
bpf/vmtest-bpf-next-VM_Test-26 success Logs for test_progs_no_alu32_parallel on s390x with gcc
bpf/vmtest-bpf-next-VM_Test-36 success Logs for test_verifier on s390x with gcc

Commit Message

Daniel T. Lee Dec. 24, 2022, 7:15 a.m. UTC 
Syscall tracing using kprobe is quite unstable. Since it uses the exact
name of the kernel function, the program might broke due to the rename
of a function. The problem can also be caused by a changes in the
arguments of the function to which the kprobe connects.

In this commit, ksyscall is used instead of kprobe. By using ksyscall,
libbpf will detect the appropriate kernel function name.
(e.g. sys_write -> __s390_sys_write). This eliminates the need to worry
about which wrapper function to attach in order to parse arguments.

In addition, ksyscall provides more fine method with attaching system
call, the coarse SYSCALL helper at trace_common.h can be removed.

Signed-off-by: Daniel T. Lee <danieltimlee@gmail.com>
---
 samples/bpf/map_perf_test_kern.c                | 17 ++++++++---------
 .../bpf/test_current_task_under_cgroup_kern.c   |  3 +--
 samples/bpf/test_map_in_map_kern.c              |  1 -
 samples/bpf/test_probe_write_user_kern.c        |  3 +--
 samples/bpf/trace_common.h                      | 13 -------------
 samples/bpf/trace_output_kern.c                 |  3 +--
 samples/bpf/tracex2_kern.c                      |  3 +--
 7 files changed, 12 insertions(+), 31 deletions(-)
 delete mode 100644 samples/bpf/trace_common.h
diff mbox series

Patch

diff --git a/samples/bpf/map_perf_test_kern.c b/samples/bpf/map_perf_test_kern.c
index 7342c5b2f278..874e2f7e3d5d 100644
--- a/samples/bpf/map_perf_test_kern.c
+++ b/samples/bpf/map_perf_test_kern.c
@@ -11,7 +11,6 @@ 
 #include <bpf/bpf_helpers.h>
 #include <bpf/bpf_tracing.h>
 #include <bpf/bpf_core_read.h>
-#include "trace_common.h"
 
 #define MAX_ENTRIES 1000
 #define MAX_NR_CPUS 1024
@@ -102,7 +101,7 @@  struct {
 	__uint(max_entries, MAX_ENTRIES);
 } lru_hash_lookup_map SEC(".maps");
 
-SEC("kprobe/" SYSCALL(sys_getuid))
+SEC("ksyscall/getuid")
 int stress_hmap(struct pt_regs *ctx)
 {
 	u32 key = bpf_get_current_pid_tgid();
@@ -120,7 +119,7 @@  int stress_hmap(struct pt_regs *ctx)
 	return 0;
 }
 
-SEC("kprobe/" SYSCALL(sys_geteuid))
+SEC("ksyscall/geteuid")
 int stress_percpu_hmap(struct pt_regs *ctx)
 {
 	u32 key = bpf_get_current_pid_tgid();
@@ -137,7 +136,7 @@  int stress_percpu_hmap(struct pt_regs *ctx)
 	return 0;
 }
 
-SEC("kprobe/" SYSCALL(sys_getgid))
+SEC("ksyscall/getgid")
 int stress_hmap_alloc(struct pt_regs *ctx)
 {
 	u32 key = bpf_get_current_pid_tgid();
@@ -154,7 +153,7 @@  int stress_hmap_alloc(struct pt_regs *ctx)
 	return 0;
 }
 
-SEC("kprobe/" SYSCALL(sys_getegid))
+SEC("ksyscall/getegid")
 int stress_percpu_hmap_alloc(struct pt_regs *ctx)
 {
 	u32 key = bpf_get_current_pid_tgid();
@@ -171,7 +170,7 @@  int stress_percpu_hmap_alloc(struct pt_regs *ctx)
 	return 0;
 }
 
-SEC("kprobe/" SYSCALL(sys_connect))
+SEC("ksyscall/connect")
 int stress_lru_hmap_alloc(struct pt_regs *ctx)
 {
 	struct pt_regs *real_regs = (struct pt_regs *)PT_REGS_PARM1_CORE(ctx);
@@ -251,7 +250,7 @@  int stress_lru_hmap_alloc(struct pt_regs *ctx)
 	return 0;
 }
 
-SEC("kprobe/" SYSCALL(sys_gettid))
+SEC("ksyscall/gettid")
 int stress_lpm_trie_map_alloc(struct pt_regs *ctx)
 {
 	union {
@@ -273,7 +272,7 @@  int stress_lpm_trie_map_alloc(struct pt_regs *ctx)
 	return 0;
 }
 
-SEC("kprobe/" SYSCALL(sys_getpgid))
+SEC("ksyscall/getpgid")
 int stress_hash_map_lookup(struct pt_regs *ctx)
 {
 	u32 key = 1, i;
@@ -286,7 +285,7 @@  int stress_hash_map_lookup(struct pt_regs *ctx)
 	return 0;
 }
 
-SEC("kprobe/" SYSCALL(sys_getppid))
+SEC("ksyscall/getppid")
 int stress_array_map_lookup(struct pt_regs *ctx)
 {
 	u32 key = 1, i;
diff --git a/samples/bpf/test_current_task_under_cgroup_kern.c b/samples/bpf/test_current_task_under_cgroup_kern.c
index fbd43e2bb4d3..541fc861b984 100644
--- a/samples/bpf/test_current_task_under_cgroup_kern.c
+++ b/samples/bpf/test_current_task_under_cgroup_kern.c
@@ -10,7 +10,6 @@ 
 #include <linux/version.h>
 #include <bpf/bpf_helpers.h>
 #include <uapi/linux/utsname.h>
-#include "trace_common.h"
 
 struct {
 	__uint(type, BPF_MAP_TYPE_CGROUP_ARRAY);
@@ -27,7 +26,7 @@  struct {
 } perf_map SEC(".maps");
 
 /* Writes the last PID that called sync to a map at index 0 */
-SEC("kprobe/" SYSCALL(sys_sync))
+SEC("ksyscall/sync")
 int bpf_prog1(struct pt_regs *ctx)
 {
 	u64 pid = bpf_get_current_pid_tgid();
diff --git a/samples/bpf/test_map_in_map_kern.c b/samples/bpf/test_map_in_map_kern.c
index b0200c8eac09..0e17f9ade5c5 100644
--- a/samples/bpf/test_map_in_map_kern.c
+++ b/samples/bpf/test_map_in_map_kern.c
@@ -13,7 +13,6 @@ 
 #include <bpf/bpf_helpers.h>
 #include <bpf/bpf_tracing.h>
 #include <bpf/bpf_core_read.h>
-#include "trace_common.h"
 
 #define MAX_NR_PORTS 65536
 
diff --git a/samples/bpf/test_probe_write_user_kern.c b/samples/bpf/test_probe_write_user_kern.c
index 220a96438d75..d60cabaaf753 100644
--- a/samples/bpf/test_probe_write_user_kern.c
+++ b/samples/bpf/test_probe_write_user_kern.c
@@ -11,7 +11,6 @@ 
 #include <bpf/bpf_helpers.h>
 #include <bpf/bpf_tracing.h>
 #include <bpf/bpf_core_read.h>
-#include "trace_common.h"
 
 struct {
 	__uint(type, BPF_MAP_TYPE_HASH);
@@ -28,7 +27,7 @@  struct {
  * This example sits on a syscall, and the syscall ABI is relatively stable
  * of course, across platforms, and over time, the ABI may change.
  */
-SEC("kprobe/" SYSCALL(sys_connect))
+SEC("ksyscall/connect")
 int bpf_prog1(struct pt_regs *ctx)
 {
 	struct pt_regs *real_regs = (struct pt_regs *)PT_REGS_PARM1_CORE(ctx);
diff --git a/samples/bpf/trace_common.h b/samples/bpf/trace_common.h
deleted file mode 100644
index 8cb5400aed1f..000000000000
--- a/samples/bpf/trace_common.h
+++ /dev/null
@@ -1,13 +0,0 @@ 
-// SPDX-License-Identifier: GPL-2.0
-#ifndef __TRACE_COMMON_H
-#define __TRACE_COMMON_H
-
-#ifdef __x86_64__
-#define SYSCALL(SYS) "__x64_" __stringify(SYS)
-#elif defined(__s390x__)
-#define SYSCALL(SYS) "__s390x_" __stringify(SYS)
-#else
-#define SYSCALL(SYS)  __stringify(SYS)
-#endif
-
-#endif
diff --git a/samples/bpf/trace_output_kern.c b/samples/bpf/trace_output_kern.c
index b64815af0943..a481abf8c4c5 100644
--- a/samples/bpf/trace_output_kern.c
+++ b/samples/bpf/trace_output_kern.c
@@ -2,7 +2,6 @@ 
 #include <linux/version.h>
 #include <uapi/linux/bpf.h>
 #include <bpf/bpf_helpers.h>
-#include "trace_common.h"
 
 struct {
 	__uint(type, BPF_MAP_TYPE_PERF_EVENT_ARRAY);
@@ -11,7 +10,7 @@  struct {
 	__uint(max_entries, 2);
 } my_map SEC(".maps");
 
-SEC("kprobe/" SYSCALL(sys_write))
+SEC("ksyscall/write")
 int bpf_prog1(struct pt_regs *ctx)
 {
 	struct S {
diff --git a/samples/bpf/tracex2_kern.c b/samples/bpf/tracex2_kern.c
index 5bc696bac27d..ecdca9620ece 100644
--- a/samples/bpf/tracex2_kern.c
+++ b/samples/bpf/tracex2_kern.c
@@ -10,7 +10,6 @@ 
 #include <uapi/linux/bpf.h>
 #include <bpf/bpf_helpers.h>
 #include <bpf/bpf_tracing.h>
-#include "trace_common.h"
 
 struct {
 	__uint(type, BPF_MAP_TYPE_HASH);
@@ -78,7 +77,7 @@  struct {
 	__uint(max_entries, 1024);
 } my_hist_map SEC(".maps");
 
-SEC("kprobe/" SYSCALL(sys_write))
+SEC("ksyscall/write")
 int bpf_prog3(struct pt_regs *ctx)
 {
 	long write_size = PT_REGS_PARM3(ctx);