Commit e74cb1b4 authored by Puranjay Mohan's avatar Puranjay Mohan Committed by Alexei Starovoitov
Browse files

arm64: stacktrace: Implement arch_bpf_stack_walk() for the BPF JIT 



This will be used by bpf_throw() to unwind till the program marked as
exception boundary and run the callback with the stack of the main
program.

This is required for supporting BPF exceptions on ARM64.

Signed-off-by: default avatarPuranjay Mohan <puranjay12@gmail.com>
Acked-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
Link: https://lore.kernel.org/r/20240201125225.72796-2-puranjay12@gmail.com


Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
parent 2ab256e9

arch/arm64/kernel/stacktrace.c

+26 −0
Original line number Diff line number Diff line
@@ -7,6 +7,7 @@ 
#include <linux/kernel.h>

#include <linux/efi.h>

#include <linux/export.h>

#include <linux/filter.h>

#include <linux/ftrace.h>

#include <linux/kprobes.h>

#include <linux/sched.h>
@@ -266,6 +267,31 @@ noinline noinstr void arch_stack_walk(stack_trace_consume_fn consume_entry, 
	kunwind_stack_walk(arch_kunwind_consume_entry, &data, task, regs);

}



struct bpf_unwind_consume_entry_data {

	bool (*consume_entry)(void *cookie, u64 ip, u64 sp, u64 fp);

	void *cookie;

};



static bool

arch_bpf_unwind_consume_entry(const struct kunwind_state *state, void *cookie)

{

	struct bpf_unwind_consume_entry_data *data = cookie;



	return data->consume_entry(data->cookie, state->common.pc, 0,

				   state->common.fp);

}



noinline noinstr void arch_bpf_stack_walk(bool (*consume_entry)(void *cookie, u64 ip, u64 sp,

								u64 fp), void *cookie)

{

	struct bpf_unwind_consume_entry_data data = {

		.consume_entry = consume_entry,

		.cookie = cookie,

	};



	kunwind_stack_walk(arch_bpf_unwind_consume_entry, &data, current, NULL);

}



static bool dump_backtrace_entry(void *arg, unsigned long where)

{

	char *loglvl = arg;