Commit 852486b3 authored by Alexei Starovoitov's avatar Alexei Starovoitov
Browse files

x86/cfi,bpf: Fix bpf_exception_cb() signature 



As per the earlier patches, BPF sub-programs have bpf_callback_t
signature and CFI expects callers to have matching signature. This is
violated by bpf_prog_aux::bpf_exception_cb().

[peterz: Changelog]
Reported-by: default avatarPeter Zijlstra <peterz@infradead.org>
Signed-off-by: default avatarAlexei Starovoitov <alexei.starovoitov@gmail.com>
Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/CAADnVQ+Z7UcXXBBhMubhcMM=R-dExk-uHtfOLtoLxQ1XxEpqEA@mail.gmail.com
Link: https://lore.kernel.org/r/20231215092707.910319166@infradead.org


Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
parent e4c00339

include/linux/bpf.h

+1 −1
Original line number Diff line number Diff line
@@ -1484,7 +1484,7 @@ struct bpf_prog_aux { 
	int cgroup_atype; /* enum cgroup_bpf_attach_type */

	struct bpf_map *cgroup_storage[MAX_BPF_CGROUP_STORAGE_TYPE];

	char name[BPF_OBJ_NAME_LEN];

	unsigned int (*bpf_exception_cb)(u64 cookie, u64 sp, u64 bp);

	u64 (*bpf_exception_cb)(u64 cookie, u64 sp, u64 bp, u64, u64);

#ifdef CONFIG_SECURITY

	void *security;

#endif

kernel/bpf/helpers.c

+1 −1
Original line number Diff line number Diff line
@@ -2537,7 +2537,7 @@ __bpf_kfunc void bpf_throw(u64 cookie) 
	 * which skips compiler generated instrumentation to do the same.

	 */

	kasan_unpoison_task_stack_below((void *)(long)ctx.sp);

	ctx.aux->bpf_exception_cb(cookie, ctx.sp, ctx.bp);

	ctx.aux->bpf_exception_cb(cookie, ctx.sp, ctx.bp, 0, 0);

	WARN(1, "A call to BPF exception callback should never return\n");

}