From 64893e83f916145fd23182209009e9d2ce36d2df Mon Sep 17 00:00:00 2001 From: =?utf8?q?Daniel=20M=C3=BCller?= Date: Thu, 28 Jul 2022 22:23:45 +0000 Subject: [PATCH] libbpf: Support PPC in arch_specific_syscall_pfx MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit Commit 708ac5bea0ce ("libbpf: add ksyscall/kretsyscall sections support for syscall kprobes") added the arch_specific_syscall_pfx() function, which returns a string representing the architecture in use. As it turns out this function is currently not aware of Power PC, where NULL is returned. That's being flagged by the libbpf CI system, which builds for ppc64le and the compiler sees a NULL pointer being passed in to a %s format string. With this change we add representations for two more architectures, for Power PC and Power PC 64, and also adjust the string format logic to handle NULL pointers gracefully, in an attempt to prevent similar issues with other architectures in the future. Fixes: 708ac5bea0ce ("libbpf: add ksyscall/kretsyscall sections support for syscall kprobes") Signed-off-by: Daniel Müller Signed-off-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20220728222345.3125975-1-deso@posteo.net --- tools/lib/bpf/libbpf.c | 11 ++++++++++- 1 file changed, 10 insertions(+), 1 deletion(-) diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index b01fe01..50d4181 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -9995,6 +9995,10 @@ static const char *arch_specific_syscall_pfx(void) return "mips"; #elif defined(__riscv) return "riscv"; +#elif defined(__powerpc__) + return "powerpc"; +#elif defined(__powerpc64__) + return "powerpc64"; #else return NULL; #endif @@ -10127,8 +10131,13 @@ struct bpf_link *bpf_program__attach_ksyscall(const struct bpf_program *prog, return libbpf_err_ptr(-EINVAL); if (kernel_supports(prog->obj, FEAT_SYSCALL_WRAPPER)) { + /* arch_specific_syscall_pfx() should never return NULL here + * because it is guarded by kernel_supports(). However, since + * compiler does not know that we have an explicit conditional + * as well. + */ snprintf(func_name, sizeof(func_name), "__%s_sys_%s", - arch_specific_syscall_pfx(), syscall_name); + arch_specific_syscall_pfx() ? : "", syscall_name); } else { snprintf(func_name, sizeof(func_name), "__se_sys_%s", syscall_name); } -- 2.7.4