This is a note to let you know that I've just added the patch titled
bpf: Split off basic BPF verifier log into separate file
to the 6.1-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
bpf-split-off-basic-bpf-verifier-log-into-separate-f.patch
and it can be found in the queue-6.1 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 9852eff65c9648ff0ec9e3518777efb6f7ee74ea
Author: Andrii Nakryiko <andrii@xxxxxxxxxx>
Date: Thu Apr 6 16:41:47 2023 -0700
bpf: Split off basic BPF verifier log into separate file
[ Upstream commit 4294a0a7ab6282c3d92f03de84e762dda993c93d ]
kernel/bpf/verifier.c file is large and growing larger all the time. So
it's good to start splitting off more or less self-contained parts into
separate files to keep source code size (somewhat) somewhat under
control.
This patch is a one step in this direction, moving some of BPF verifier log
routines into a separate kernel/bpf/log.c. Right now it's most low-level
and isolated routines to append data to log, reset log to previous
position, etc. Eventually we could probably move verifier state
printing logic here as well, but this patch doesn't attempt to do that
yet.
Subsequent patches will add more logic to verifier log management, so
having basics in a separate file will make sure verifier.c doesn't grow
more with new changes.
Signed-off-by: Andrii Nakryiko <andrii@xxxxxxxxxx>
Signed-off-by: Daniel Borkmann <daniel@xxxxxxxxxxxxx>
Acked-by: Lorenz Bauer <lmb@xxxxxxxxxxxxx>
Link: https://lore.kernel.org/bpf/20230406234205.323208-2-andrii@xxxxxxxxxx
Stable-dep-of: cff36398bd4c ("bpf: drop unnecessary user-triggerable WARN_ONCE in verifierl log")
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/include/linux/bpf_verifier.h b/include/linux/bpf_verifier.h
index 131adc98080b8..33b073deb8c17 100644
--- a/include/linux/bpf_verifier.h
+++ b/include/linux/bpf_verifier.h
@@ -445,11 +445,6 @@ struct bpf_verifier_log {
u32 len_total;
};
-static inline bool bpf_verifier_log_full(const struct bpf_verifier_log *log)
-{
- return log->len_used >= log->len_total - 1;
-}
-
#define BPF_LOG_LEVEL1 1
#define BPF_LOG_LEVEL2 2
#define BPF_LOG_STATS 4
@@ -459,6 +454,11 @@ static inline bool bpf_verifier_log_full(const struct bpf_verifier_log *log)
#define BPF_LOG_MIN_ALIGNMENT 8U
#define BPF_LOG_ALIGNMENT 40U
+static inline bool bpf_verifier_log_full(const struct bpf_verifier_log *log)
+{
+ return log->len_used >= log->len_total - 1;
+}
+
static inline bool bpf_verifier_log_needed(const struct bpf_verifier_log *log)
{
return log &&
@@ -466,13 +466,6 @@ static inline bool bpf_verifier_log_needed(const struct bpf_verifier_log *log)
log->level == BPF_LOG_KERNEL);
}
-static inline bool
-bpf_verifier_log_attr_valid(const struct bpf_verifier_log *log)
-{
- return log->len_total >= 128 && log->len_total <= UINT_MAX >> 2 &&
- log->level && log->ubuf && !(log->level & ~BPF_LOG_MASK);
-}
-
#define BPF_MAX_SUBPROGS 256
struct bpf_subprog_info {
@@ -556,12 +549,14 @@ struct bpf_verifier_env {
char type_str_buf[TYPE_STR_BUF_LEN];
};
+bool bpf_verifier_log_attr_valid(const struct bpf_verifier_log *log);
__printf(2, 0) void bpf_verifier_vlog(struct bpf_verifier_log *log,
const char *fmt, va_list args);
__printf(2, 3) void bpf_verifier_log_write(struct bpf_verifier_env *env,
const char *fmt, ...);
__printf(2, 3) void bpf_log(struct bpf_verifier_log *log,
const char *fmt, ...);
+void bpf_vlog_reset(struct bpf_verifier_log *log, u32 new_pos);
static inline struct bpf_func_state *cur_func(struct bpf_verifier_env *env)
{
diff --git a/kernel/bpf/Makefile b/kernel/bpf/Makefile
index 341c94f208f4c..5b86ea9f09c46 100644
--- a/kernel/bpf/Makefile
+++ b/kernel/bpf/Makefile
@@ -6,7 +6,8 @@ cflags-nogcse-$(CONFIG_X86)$(CONFIG_CC_IS_GCC) := -fno-gcse
endif
CFLAGS_core.o += $(call cc-disable-warning, override-init) $(cflags-nogcse-yy)
-obj-$(CONFIG_BPF_SYSCALL) += syscall.o verifier.o inode.o helpers.o tnum.o bpf_iter.o map_iter.o task_iter.o prog_iter.o link_iter.o
+obj-$(CONFIG_BPF_SYSCALL) += syscall.o verifier.o inode.o helpers.o tnum.o log.o
+obj-$(CONFIG_BPF_SYSCALL) += bpf_iter.o map_iter.o task_iter.o prog_iter.o link_iter.o
obj-$(CONFIG_BPF_SYSCALL) += hashtab.o arraymap.o percpu_freelist.o bpf_lru_list.o lpm_trie.o map_in_map.o bloom_filter.o
obj-$(CONFIG_BPF_SYSCALL) += local_storage.o queue_stack_maps.o ringbuf.o
obj-$(CONFIG_BPF_SYSCALL) += bpf_local_storage.o bpf_task_storage.o
diff --git a/kernel/bpf/log.c b/kernel/bpf/log.c
new file mode 100644
index 0000000000000..920061e38d2e1
--- /dev/null
+++ b/kernel/bpf/log.c
@@ -0,0 +1,85 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/* Copyright (c) 2011-2014 PLUMgrid, http://plumgrid.com
+ * Copyright (c) 2016 Facebook
+ * Copyright (c) 2018 Covalent IO, Inc. http://covalent.io
+ */
+#include <uapi/linux/btf.h>
+#include <linux/kernel.h>
+#include <linux/types.h>
+#include <linux/bpf.h>
+#include <linux/bpf_verifier.h>
+
+bool bpf_verifier_log_attr_valid(const struct bpf_verifier_log *log)
+{
+ return log->len_total >= 128 && log->len_total <= UINT_MAX >> 2 &&
+ log->level && log->ubuf && !(log->level & ~BPF_LOG_MASK);
+}
+
+void bpf_verifier_vlog(struct bpf_verifier_log *log, const char *fmt,
+ va_list args)
+{
+ unsigned int n;
+
+ n = vscnprintf(log->kbuf, BPF_VERIFIER_TMP_LOG_SIZE, fmt, args);
+
+ WARN_ONCE(n >= BPF_VERIFIER_TMP_LOG_SIZE - 1,
+ "verifier log line truncated - local buffer too short\n");
+
+ if (log->level == BPF_LOG_KERNEL) {
+ bool newline = n > 0 && log->kbuf[n - 1] == '\n';
+
+ pr_err("BPF: %s%s", log->kbuf, newline ? "" : "\n");
+ return;
+ }
+
+ n = min(log->len_total - log->len_used - 1, n);
+ log->kbuf[n] = '\0';
+ if (!copy_to_user(log->ubuf + log->len_used, log->kbuf, n + 1))
+ log->len_used += n;
+ else
+ log->ubuf = NULL;
+}
+
+void bpf_vlog_reset(struct bpf_verifier_log *log, u32 new_pos)
+{
+ char zero = 0;
+
+ if (!bpf_verifier_log_needed(log))
+ return;
+
+ log->len_used = new_pos;
+ if (put_user(zero, log->ubuf + new_pos))
+ log->ubuf = NULL;
+}
+
+/* log_level controls verbosity level of eBPF verifier.
+ * 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
+ */
+__printf(2, 3) void bpf_verifier_log_write(struct bpf_verifier_env *env,
+ const char *fmt, ...)
+{
+ va_list args;
+
+ if (!bpf_verifier_log_needed(&env->log))
+ return;
+
+ va_start(args, fmt);
+ bpf_verifier_vlog(&env->log, fmt, args);
+ va_end(args);
+}
+EXPORT_SYMBOL_GPL(bpf_verifier_log_write);
+
+__printf(2, 3) void bpf_log(struct bpf_verifier_log *log,
+ const char *fmt, ...)
+{
+ va_list args;
+
+ if (!bpf_verifier_log_needed(log))
+ return;
+
+ va_start(args, fmt);
+ bpf_verifier_vlog(log, fmt, args);
+ va_end(args);
+}
+EXPORT_SYMBOL_GPL(bpf_log);
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index 8973d3c9597ce..4efa50eb07d72 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -291,61 +291,6 @@ find_linfo(const struct bpf_verifier_env *env, u32 insn_off)
return &linfo[i - 1];
}
-void bpf_verifier_vlog(struct bpf_verifier_log *log, const char *fmt,
- va_list args)
-{
- unsigned int n;
-
- n = vscnprintf(log->kbuf, BPF_VERIFIER_TMP_LOG_SIZE, fmt, args);
-
- WARN_ONCE(n >= BPF_VERIFIER_TMP_LOG_SIZE - 1,
- "verifier log line truncated - local buffer too short\n");
-
- if (log->level == BPF_LOG_KERNEL) {
- bool newline = n > 0 && log->kbuf[n - 1] == '\n';
-
- pr_err("BPF: %s%s", log->kbuf, newline ? "" : "\n");
- return;
- }
-
- n = min(log->len_total - log->len_used - 1, n);
- log->kbuf[n] = '\0';
- if (!copy_to_user(log->ubuf + log->len_used, log->kbuf, n + 1))
- log->len_used += n;
- else
- log->ubuf = NULL;
-}
-
-static void bpf_vlog_reset(struct bpf_verifier_log *log, u32 new_pos)
-{
- char zero = 0;
-
- if (!bpf_verifier_log_needed(log))
- return;
-
- log->len_used = new_pos;
- if (put_user(zero, log->ubuf + new_pos))
- log->ubuf = NULL;
-}
-
-/* log_level controls verbosity level of eBPF verifier.
- * 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
- */
-__printf(2, 3) void bpf_verifier_log_write(struct bpf_verifier_env *env,
- const char *fmt, ...)
-{
- va_list args;
-
- if (!bpf_verifier_log_needed(&env->log))
- return;
-
- va_start(args, fmt);
- bpf_verifier_vlog(&env->log, fmt, args);
- va_end(args);
-}
-EXPORT_SYMBOL_GPL(bpf_verifier_log_write);
-
__printf(2, 3) static void verbose(void *private_data, const char *fmt, ...)
{
struct bpf_verifier_env *env = private_data;
@@ -359,20 +304,6 @@ __printf(2, 3) static void verbose(void *private_data, const char *fmt, ...)
va_end(args);
}
-__printf(2, 3) void bpf_log(struct bpf_verifier_log *log,
- const char *fmt, ...)
-{
- va_list args;
-
- if (!bpf_verifier_log_needed(log))
- return;
-
- va_start(args, fmt);
- bpf_verifier_vlog(log, fmt, args);
- va_end(args);
-}
-EXPORT_SYMBOL_GPL(bpf_log);
-
static const char *ltrim(const char *s)
{
while (isspace(*s))
