From: Abhishek Dubey adubey@linux.ibm.com
This function is used by bpf_throw() to unwind the stack until frame of exception-boundary during BPF exception handling.
This function is necessary to support BPF exceptions on PowerPC.
Signed-off-by: Abhishek Dubey adubey@linux.ibm.com --- arch/powerpc/net/bpf_jit_comp64.c | 28 ++++++++++++++++++++++++++++ 1 file changed, 28 insertions(+)
diff --git a/arch/powerpc/net/bpf_jit_comp64.c b/arch/powerpc/net/bpf_jit_comp64.c index 37c547b49da8..0f3af67914d6 100644 --- a/arch/powerpc/net/bpf_jit_comp64.c +++ b/arch/powerpc/net/bpf_jit_comp64.c @@ -237,6 +237,34 @@ void bpf_jit_build_epilogue(u32 *image, struct codegen_context *ctx) bpf_jit_build_fentry_stubs(image, ctx); }
+void arch_bpf_stack_walk(bool (*consume_fn)(void *, u64, u64, u64), void *cookie) +{ + // callback processing always in current context + unsigned long fp = current_stack_frame(); + + for (;;) { + unsigned long *frame = (unsigned long *) fp; + unsigned long ip; + + if(!validate_sp(fp, current)) + return; + + ip = frame[STACK_FRAME_LR_SAVE]; + if (!ip) + break; + + /* + * consume_fn common code expects stack pointer(sp) in third + * argument. There is no sp in ppc64, rather pass frame + * pointer. + */ + if (ip && !consume_fn(cookie, ip, fp, fp)) + break; + + fp = frame[0]; + } +} + int bpf_jit_emit_func_call_rel(u32 *image, u32 *fimage, struct codegen_context *ctx, u64 func) { unsigned long func_addr = func ? ppc_function_entry((void *)func) : 0;