From 2d369b4b0044d4f6a3fa4071807f66eced0f2725 Mon Sep 17 00:00:00 2001 From: Ilya Leoshkevich Date: Tue, 26 Jul 2022 15:40:07 +0200 Subject: libbpf: Extend BPF_KSYSCALL documentation Explicitly list known quirks. Mention that socket-related syscalls can be invoked via socketcall(). Signed-off-by: Ilya Leoshkevich Signed-off-by: Daniel Borkmann Acked-by: Jiri Olsa Link: https://lore.kernel.org/bpf/20220726134008.256968-2-iii@linux.ibm.com --- tools/lib/bpf/bpf_tracing.h | 15 +++++++++++---- 1 file changed, 11 insertions(+), 4 deletions(-) (limited to 'tools/lib') diff --git a/tools/lib/bpf/bpf_tracing.h b/tools/lib/bpf/bpf_tracing.h index f4d3e1e2abe2..43ca3aff2292 100644 --- a/tools/lib/bpf/bpf_tracing.h +++ b/tools/lib/bpf/bpf_tracing.h @@ -523,10 +523,17 @@ static __always_inline typeof(name(0)) ____##name(struct pt_regs *ctx, ##args) * Original struct pt_regs * context is preserved as 'ctx' argument. This might * be necessary when using BPF helpers like bpf_perf_event_output(). * - * At the moment BPF_KSYSCALL does not handle all the calling convention - * quirks for mmap(), clone() and compat syscalls transparrently. This may or - * may not change in the future. User needs to take extra measures to handle - * such quirks explicitly, if necessary. + * At the moment BPF_KSYSCALL does not transparently handle all the calling + * convention quirks for the following syscalls: + * + * - mmap(): __ARCH_WANT_SYS_OLD_MMAP. + * - clone(): CONFIG_CLONE_BACKWARDS, CONFIG_CLONE_BACKWARDS2 and + * CONFIG_CLONE_BACKWARDS3. + * - socket-related syscalls: __ARCH_WANT_SYS_SOCKETCALL. + * - compat syscalls. + * + * This may or may not change in the future. User needs to take extra measures + * to handle such quirks explicitly, if necessary. * * This macro relies on BPF CO-RE support and virtual __kconfig externs. */ -- cgit v1.2.3