Commit d3c4db86 authored by Yauheni Kaliuta's avatar Yauheni Kaliuta Committed by Alexei Starovoitov
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tracing: bpf: use struct trace_entry in struct syscall_tp_t 



bpf tracepoint program uses struct trace_event_raw_sys_enter as
argument where trace_entry is the first field. Use the same instead
of unsigned long long since if it's amended (for example by RT
patch) it accesses data with wrong offset.

Signed-off-by: default avatarYauheni Kaliuta <ykaliuta@redhat.com>
Acked-by: default avatarYonghong Song <yonghong.song@linux.dev>
Link: https://lore.kernel.org/r/20230801075222.7717-1-ykaliuta@redhat.com


Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
parent 11108652

kernel/trace/trace_syscalls.c

+8 −4
Original line number Diff line number Diff line
@@ -555,12 +555,15 @@ static int perf_call_bpf_enter(struct trace_event_call *call, struct pt_regs *re 
			       struct syscall_trace_enter *rec)

{

	struct syscall_tp_t {

		unsigned long long regs;

		struct trace_entry ent;

		unsigned long syscall_nr;

		unsigned long args[SYSCALL_DEFINE_MAXARGS];

	} param;

	} __aligned(8) param;

	int i;



	BUILD_BUG_ON(sizeof(param.ent) < sizeof(void *));



	/* bpf prog requires 'regs' to be the first member in the ctx (a.k.a. &param) */

	*(struct pt_regs **)&param = regs;

	param.syscall_nr = rec->nr;

	for (i = 0; i < sys_data->nb_args; i++)
@@ -657,11 +660,12 @@ static int perf_call_bpf_exit(struct trace_event_call *call, struct pt_regs *reg 
			      struct syscall_trace_exit *rec)

{

	struct syscall_tp_t {

		unsigned long long regs;

		struct trace_entry ent;

		unsigned long syscall_nr;

		unsigned long ret;

	} param;

	} __aligned(8) param;



	/* bpf prog requires 'regs' to be the first member in the ctx (a.k.a. &param) */

	*(struct pt_regs **)&param = regs;

	param.syscall_nr = rec->nr;

	param.ret = rec->ret;