linux-stable.git/tools/testing/selftests/bpf/test_get_stack_rawtp.c, branch linux-5.0.y Linux kernel stable tree tools/bpf: add a test for bpf_get_stack with raw tracepoint prog 2018-04-29T15:45:54+00:00 Yonghong Song yhs@fb.com 2018-04-29T05:28:15+00:00 173965fbfba596c02fa128966c2a33cb88afcd7f The test attached a raw_tracepoint program to raw_syscalls/sys_enter. It tested to get stack for user space, kernel space and user space with build_id request. It also tested to get user and kernel stack into the same buffer with back-to-back bpf_get_stack helper calls. If jit is not enabled, the user space application will check to ensure that the kernel function for raw_tracepoint ___bpf_prog_run is part of the stack. If jit is enabled, we did not have a reliable way to verify the kernel stack, so just assume the kernel stack is good when the kernel stack size is greater than 0. Signed-off-by: Yonghong Song <yhs@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> 
The test attached a raw_tracepoint program to raw_syscalls/sys_enter.
It tested to get stack for user space, kernel space and user
space with build_id request. It also tested to get user
and kernel stack into the same buffer with back-to-back
bpf_get_stack helper calls.

If jit is not enabled, the user space application will check
to ensure that the kernel function for raw_tracepoint
___bpf_prog_run is part of the stack.

If jit is enabled, we did not have a reliable way to
verify the kernel stack, so just assume the kernel stack
is good when the kernel stack size is greater than 0.

Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>