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authorArtem Savkov <asavkov@redhat.com>2023-10-13 08:42:19 +0300
committerAndrii Nakryiko <andrii@kernel.org>2023-10-13 22:39:36 +0300
commitba8ea72388a192c10f1ee5f5a4a32332e7cced76 (patch)
treef6b556d3e5fb7351d63c793c75e30def44909994 /tools
parent9c1292eca243821249fa99f40175b0660d9329e3 (diff)
downloadlinux-ba8ea72388a192c10f1ee5f5a4a32332e7cced76.tar.xz
bpf: Change syscall_nr type to int in struct syscall_tp_t
linux-rt-devel tree contains a patch (b1773eac3f29c ("sched: Add support for lazy preemption")) that adds an extra member to struct trace_entry. This causes the offset of args field in struct trace_event_raw_sys_enter be different from the one in struct syscall_trace_enter: struct trace_event_raw_sys_enter { struct trace_entry ent; /* 0 12 */ /* XXX last struct has 3 bytes of padding */ /* XXX 4 bytes hole, try to pack */ long int id; /* 16 8 */ long unsigned int args[6]; /* 24 48 */ /* --- cacheline 1 boundary (64 bytes) was 8 bytes ago --- */ char __data[]; /* 72 0 */ /* size: 72, cachelines: 2, members: 4 */ /* sum members: 68, holes: 1, sum holes: 4 */ /* paddings: 1, sum paddings: 3 */ /* last cacheline: 8 bytes */ }; struct syscall_trace_enter { struct trace_entry ent; /* 0 12 */ /* XXX last struct has 3 bytes of padding */ int nr; /* 12 4 */ long unsigned int args[]; /* 16 0 */ /* size: 16, cachelines: 1, members: 3 */ /* paddings: 1, sum paddings: 3 */ /* last cacheline: 16 bytes */ }; This, in turn, causes perf_event_set_bpf_prog() fail while running bpf test_profiler testcase because max_ctx_offset is calculated based on the former struct, while off on the latter: 10488 if (is_tracepoint || is_syscall_tp) { 10489 int off = trace_event_get_offsets(event->tp_event); 10490 10491 if (prog->aux->max_ctx_offset > off) 10492 return -EACCES; 10493 } What bpf program is actually getting is a pointer to struct syscall_tp_t, defined in kernel/trace/trace_syscalls.c. This patch fixes the problem by aligning struct syscall_tp_t with struct syscall_trace_(enter|exit) and changing the tests to use these structs to dereference context. Signed-off-by: Artem Savkov <asavkov@redhat.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: Steven Rostedt (Google) <rostedt@goodmis.org> Link: https://lore.kernel.org/bpf/20231013054219.172920-1-asavkov@redhat.com
Diffstat (limited to 'tools')
-rw-r--r--tools/testing/selftests/bpf/progs/profiler.inc.h2
-rw-r--r--tools/testing/selftests/bpf/progs/test_vmlinux.c4
2 files changed, 3 insertions, 3 deletions
diff --git a/tools/testing/selftests/bpf/progs/profiler.inc.h b/tools/testing/selftests/bpf/progs/profiler.inc.h
index f799d87e8700..897061930cb7 100644
--- a/tools/testing/selftests/bpf/progs/profiler.inc.h
+++ b/tools/testing/selftests/bpf/progs/profiler.inc.h
@@ -609,7 +609,7 @@ out:
}
SEC("tracepoint/syscalls/sys_enter_kill")
-int tracepoint__syscalls__sys_enter_kill(struct trace_event_raw_sys_enter* ctx)
+int tracepoint__syscalls__sys_enter_kill(struct syscall_trace_enter* ctx)
{
struct bpf_func_stats_ctx stats_ctx;
diff --git a/tools/testing/selftests/bpf/progs/test_vmlinux.c b/tools/testing/selftests/bpf/progs/test_vmlinux.c
index 4b8e37f7fd06..78b23934d9f8 100644
--- a/tools/testing/selftests/bpf/progs/test_vmlinux.c
+++ b/tools/testing/selftests/bpf/progs/test_vmlinux.c
@@ -16,12 +16,12 @@ bool kprobe_called = false;
bool fentry_called = false;
SEC("tp/syscalls/sys_enter_nanosleep")
-int handle__tp(struct trace_event_raw_sys_enter *args)
+int handle__tp(struct syscall_trace_enter *args)
{
struct __kernel_timespec *ts;
long tv_nsec;
- if (args->id != __NR_nanosleep)
+ if (args->nr != __NR_nanosleep)
return 0;
ts = (void *)args->args[0];