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authorQuentin Monnet2018-01-10 13:26:06 +0100
committerDaniel Borkmann2018-01-10 13:49:36 +0100
commit430e68d10baf55e4c40d4dd1de8201c1caf5dddd (patch)
tree901b58a149c0ed006e87af6ed5184e08cba20107 /kernel/bpf
parentnfp: bpf: add signed jump insns (diff)
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bpf: export function to write into verifier log buffer
Rename the BPF verifier `verbose()` to `bpf_verifier_log_write()` and export it, so that other components (in particular, drivers for BPF offload) can reuse the user buffer log to dump error messages at verification time. Renaming `verbose()` was necessary in order to avoid a name so generic to be exported to the global namespace. However to prevent too much pain for backports, the calls to `verbose()` in the kernel BPF verifier were not changed. Instead, use function aliasing to make `verbose` point to `bpf_verifier_log_write`. Another solution could consist in making a wrapper around `verbose()`, but since it is a variadic function, I don't see a clean way without creating two identical wrappers, one for the verifier and one to export. Signed-off-by: Quentin Monnet <quentin.monnet@netronome.com> Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Diffstat (limited to 'kernel/bpf')
-rw-r--r--kernel/bpf/verifier.c16
1 files changed, 12 insertions, 4 deletions
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index d921ab387b0b..3b2b47666180 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -169,11 +169,11 @@ struct bpf_call_arg_meta {
static DEFINE_MUTEX(bpf_verifier_lock);
/* log_level controls verbosity level of eBPF verifier.
- * verbose() is used to dump the verification trace to the log, so the user
- * can figure out what's wrong with the program
+ * bpf_verifier_log_write() is used to dump the verification trace to the log,
+ * so the user can figure out what's wrong with the program
*/
-static __printf(2, 3) void verbose(struct bpf_verifier_env *env,
- const char *fmt, ...)
+__printf(2, 3) void bpf_verifier_log_write(struct bpf_verifier_env *env,
+ const char *fmt, ...)
{
struct bpf_verifer_log *log = &env->log;
unsigned int n;
@@ -197,6 +197,14 @@ static __printf(2, 3) void verbose(struct bpf_verifier_env *env,
else
log->ubuf = NULL;
}
+EXPORT_SYMBOL_GPL(bpf_verifier_log_write);
+/* Historically bpf_verifier_log_write was called verbose, but the name was too
+ * generic for symbol export. The function was renamed, but not the calls in
+ * the verifier to avoid complicating backports. Hence the alias below.
+ */
+static __printf(2, 3) void verbose(struct bpf_verifier_env *env,
+ const char *fmt, ...)
+ __attribute__((alias("bpf_verifier_log_write")));
static bool type_is_pkt_pointer(enum bpf_reg_type type)
{