From 609320c8a22715b74b39796930c3542719f8ab62 Mon Sep 17 00:00:00 2001
From: Yonghong Song <yhs@fb.com>
Date: Thu, 7 Sep 2017 18:36:15 -0700
Subject: [PATCH] perf/bpf: fix a clang compilation issue
clang does not support variable length array for structure member.
It has the following error during compilation:
kernel/trace/trace_syscalls.c:568:17: error: fields must have a constant size:
'variable length array in structure' extension will never be supported
unsigned long args[sys_data->nb_args];
^
The fix is to use a fixed array length instead.
Reported-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---
include/linux/syscalls.h | 2 ++
kernel/trace/trace_syscalls.c | 2 +-
2 files changed, 3 insertions(+), 1 deletion(-)
diff --git a/include/linux/syscalls.h b/include/linux/syscalls.h
index 88951b795ee3d..95606a2d556fd 100644
--- a/include/linux/syscalls.h
+++ b/include/linux/syscalls.h
@@ -200,6 +200,8 @@ static inline int is_syscall_trace_event(struct trace_event_call *tp_event)
#define SYSCALL_DEFINE5(name, ...) SYSCALL_DEFINEx(5, _##name, __VA_ARGS__)
#define SYSCALL_DEFINE6(name, ...) SYSCALL_DEFINEx(6, _##name, __VA_ARGS__)
+#define SYSCALL_DEFINE_MAXARGS 6
+
#define SYSCALL_DEFINEx(x, sname, ...) \
SYSCALL_METADATA(sname, x, __VA_ARGS__) \
__SYSCALL_DEFINEx(x, sname, __VA_ARGS__)
diff --git a/kernel/trace/trace_syscalls.c b/kernel/trace/trace_syscalls.c
index 9c4eef20301cf..696afe72d3b14 100644
--- a/kernel/trace/trace_syscalls.c
+++ b/kernel/trace/trace_syscalls.c
@@ -565,7 +565,7 @@ static int perf_call_bpf_enter(struct bpf_prog *prog, struct pt_regs *regs,
struct syscall_tp_t {
unsigned long long regs;
unsigned long syscall_nr;
- unsigned long args[sys_data->nb_args];
+ unsigned long args[SYSCALL_DEFINE_MAXARGS];
} param;
int i;
--
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