Commit 7d5ad9fe authored Dec 05, 2019 by Daniel T. Lee Committed by Greg Kroah-Hartman Jan 12, 2020

samples: bpf: fix syscall_tp due to unused syscall



[ Upstream commit fe3300897cbfd76c6cb825776e5ac0ca50a91ca4 ]

Currently, open() is called from the user program and it calls the syscall
'sys_openat', not the 'sys_open'. This leads to an error of the program
of user side, due to the fact that the counter maps are zero since no
function such 'sys_open' is called.

This commit adds the kernel bpf program which are attached to the
tracepoint 'sys_enter_openat' and 'sys_enter_openat'.

Fixes: 1da236b6 ("bpf: add a test case for syscalls/sys_{enter|exit}_* tracepoints")
Signed-off-by: Daniel T. Lee <danieltimlee@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

parent 5663eb75

samples/bpf/syscall_tp_kern.c

+16 −2

Original line number	Diff line number	Diff line
		@@ -50,13 +50,27 @@ static __always_inline void count(void *map)
		SEC("tracepoint/syscalls/sys_enter_open")
		int trace_enter_open(struct syscalls_enter_open_args *ctx)
		{
		count((void *)&enter_open_map);
		count(&enter_open_map);
		return 0;
		}

		SEC("tracepoint/syscalls/sys_enter_openat")
		int trace_enter_open_at(struct syscalls_enter_open_args *ctx)
		{
		count(&enter_open_map);
		return 0;
		}

		SEC("tracepoint/syscalls/sys_exit_open")
		int trace_enter_exit(struct syscalls_exit_open_args *ctx)
		{
		count((void *)&exit_open_map);
		count(&exit_open_map);
		return 0;
		}

		SEC("tracepoint/syscalls/sys_exit_openat")
		int trace_enter_exit_at(struct syscalls_exit_open_args *ctx)
		{
		count(&exit_open_map);
		return 0;
		}