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: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Alexei Starovoitov <alexei.starovoitov@gmail.com>
Signed-off-by: Peter 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: Alexei Starovoitov <ast@kernel.org>

diff --git a/include/linux/bpf.h b/include/linux/bpf.h
index db46b3359bf5fc5569de336169d967980fc20fb5..5e694934cf37a31a25e7726653f513d495dadc7f 100644 (file)
--- a/include/linux/bpf.h
+++ b/include/linux/bpf.h
@@ -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

diff --git a/kernel/bpf/helpers.c b/kernel/bpf/helpers.c
index e0c0e3676df8572c7fd6fac4c6315d42e2cd307c..07fd4b5704f368beb15833fcb920c6d1676c5823 100644 (file)
--- a/kernel/bpf/helpers.c
+++ b/kernel/bpf/helpers.c
@@ -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");
 }