* [PATCH 1/2] tracing/probes: Fix to show a parse error for bad type for $comm
2024-01-23 15:02 [PATCH 0/2] tracing/probes: Fix probe event argument parser Masami Hiramatsu (Google)
@ 2024-01-23 15:02 ` Masami Hiramatsu (Google)
2024-01-23 15:03 ` [PATCH 2/2] tracing/probes: Fix to set arg size and fmt after setting type from BTF Masami Hiramatsu (Google)
1 sibling, 0 replies; 3+ messages in thread
From: Masami Hiramatsu (Google) @ 2024-01-23 15:02 UTC (permalink / raw)
To: Steven Rostedt; +Cc: linux-trace-kernel, linux-kernel
From: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Fix to show a parse error for bad type (non-string) for $comm/$COMM and
immediate-string. With this fix, error_log file shows appropriate error
message as below.
/sys/kernel/tracing # echo 'p vfs_read $comm:u32' >> kprobe_events
sh: write error: Invalid argument
/sys/kernel/tracing # echo 'p vfs_read \"hoge":u32' >> kprobe_events
sh: write error: Invalid argument
/sys/kernel/tracing # cat error_log
[ 30.144183] trace_kprobe: error: $comm and immediate-string only accepts string type
Command: p vfs_read $comm:u32
^
[ 62.618500] trace_kprobe: error: $comm and immediate-string only accepts string type
Command: p vfs_read \"hoge":u32
^
Fixes: 3dd1f7f24f8c ("tracing: probeevent: Fix to make the type of $comm string")
Cc: stable@vger.kernel.org
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
---
kernel/trace/trace_probe.c | 7 +++++--
kernel/trace/trace_probe.h | 3 ++-
2 files changed, 7 insertions(+), 3 deletions(-)
diff --git a/kernel/trace/trace_probe.c b/kernel/trace/trace_probe.c
index 4dc74d73fc1d..c6da5923e5b9 100644
--- a/kernel/trace/trace_probe.c
+++ b/kernel/trace/trace_probe.c
@@ -1159,9 +1159,12 @@ static int traceprobe_parse_probe_arg_body(const char *argv, ssize_t *size,
if (!(ctx->flags & TPARG_FL_TEVENT) &&
(strcmp(arg, "$comm") == 0 || strcmp(arg, "$COMM") == 0 ||
strncmp(arg, "\\\"", 2) == 0)) {
- /* The type of $comm must be "string", and not an array. */
- if (parg->count || (t && strcmp(t, "string")))
+ /* The type of $comm must be "string", and not an array type. */
+ if (parg->count || (t && strcmp(t, "string"))) {
+ trace_probe_log_err(ctx->offset + (t ? (t - arg) : 0),
+ NEED_STRING_TYPE);
goto out;
+ }
parg->type = find_fetch_type("string", ctx->flags);
} else
parg->type = find_fetch_type(t, ctx->flags);
diff --git a/kernel/trace/trace_probe.h b/kernel/trace/trace_probe.h
index 850d9ecb6765..c1877d018269 100644
--- a/kernel/trace/trace_probe.h
+++ b/kernel/trace/trace_probe.h
@@ -515,7 +515,8 @@ extern int traceprobe_define_arg_fields(struct trace_event_call *event_call,
C(BAD_HYPHEN, "Failed to parse single hyphen. Forgot '>'?"), \
C(NO_BTF_FIELD, "This field is not found."), \
C(BAD_BTF_TID, "Failed to get BTF type info."),\
- C(BAD_TYPE4STR, "This type does not fit for string."),
+ C(BAD_TYPE4STR, "This type does not fit for string."),\
+ C(NEED_STRING_TYPE, "$comm and immediate-string only accepts string type"),
#undef C
#define C(a, b) TP_ERR_##a
^ permalink raw reply related [flat|nested] 3+ messages in thread* [PATCH 2/2] tracing/probes: Fix to set arg size and fmt after setting type from BTF
2024-01-23 15:02 [PATCH 0/2] tracing/probes: Fix probe event argument parser Masami Hiramatsu (Google)
2024-01-23 15:02 ` [PATCH 1/2] tracing/probes: Fix to show a parse error for bad type for $comm Masami Hiramatsu (Google)
@ 2024-01-23 15:03 ` Masami Hiramatsu (Google)
1 sibling, 0 replies; 3+ messages in thread
From: Masami Hiramatsu (Google) @ 2024-01-23 15:03 UTC (permalink / raw)
To: Steven Rostedt; +Cc: linux-trace-kernel, linux-kernel
From: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Since the BTF type setting updates probe_arg::type, the type size
calculation and setting print-fmt should be done after that.
Without this fix, the argument size and print-fmt can be wrong.
Fixes: b576e09701c7 ("tracing/probes: Support function parameters if BTF is available")
Cc: stable@vger.kernel.org
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
---
kernel/trace/trace_probe.c | 25 +++++++++++++------------
1 file changed, 13 insertions(+), 12 deletions(-)
diff --git a/kernel/trace/trace_probe.c b/kernel/trace/trace_probe.c
index c6da5923e5b9..34289f9c6707 100644
--- a/kernel/trace/trace_probe.c
+++ b/kernel/trace/trace_probe.c
@@ -1172,18 +1172,6 @@ static int traceprobe_parse_probe_arg_body(const char *argv, ssize_t *size,
trace_probe_log_err(ctx->offset + (t ? (t - arg) : 0), BAD_TYPE);
goto out;
}
- parg->offset = *size;
- *size += parg->type->size * (parg->count ?: 1);
-
- ret = -ENOMEM;
- if (parg->count) {
- len = strlen(parg->type->fmttype) + 6;
- parg->fmt = kmalloc(len, GFP_KERNEL);
- if (!parg->fmt)
- goto out;
- snprintf(parg->fmt, len, "%s[%d]", parg->type->fmttype,
- parg->count);
- }
code = tmp = kcalloc(FETCH_INSN_MAX, sizeof(*code), GFP_KERNEL);
if (!code)
@@ -1207,6 +1195,19 @@ static int traceprobe_parse_probe_arg_body(const char *argv, ssize_t *size,
goto fail;
}
}
+ parg->offset = *size;
+ *size += parg->type->size * (parg->count ?: 1);
+
+ if (parg->count) {
+ len = strlen(parg->type->fmttype) + 6;
+ parg->fmt = kmalloc(len, GFP_KERNEL);
+ if (!parg->fmt) {
+ ret = -ENOMEM;
+ goto out;
+ }
+ snprintf(parg->fmt, len, "%s[%d]", parg->type->fmttype,
+ parg->count);
+ }
ret = -EINVAL;
/* Store operation */
^ permalink raw reply related [flat|nested] 3+ messages in thread