6.6-stable review patch. If anyone has any objections, please let me know.
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From: Masami Hiramatsu (Google) mhiramat@kernel.org
commit 8c427cc2fa73684ea140999e121b7b6c1c717632 upstream.
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 ^ Link: https://lore.kernel.org/all/170602215411.215583.2238016352271091852.stgit@de...
Fixes: 3dd1f7f24f8c ("tracing: probeevent: Fix to make the type of $comm string") Cc: stable@vger.kernel.org Signed-off-by: Masami Hiramatsu (Google) mhiramat@kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- kernel/trace/trace_probe.c | 7 +++++-- kernel/trace/trace_probe.h | 3 ++- 2 files changed, 7 insertions(+), 3 deletions(-)
--- a/kernel/trace/trace_probe.c +++ b/kernel/trace/trace_probe.c @@ -1159,9 +1159,12 @@ static int traceprobe_parse_probe_arg_bo if (!(ctx->flags & TPARG_FL_TEVENT) && (strcmp(arg, "$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 $comm must be "string", and not an array type. */ + if (parg->count || (t && strcmp(t, "string"))) { + trace_probe_log_err(ctx->offset + (t ? (t - arg) : 0), + NEED_STRING_TYPE); goto out; + } parg->type = find_fetch_type("string", ctx->flags); } else parg->type = find_fetch_type(t, ctx->flags); --- a/kernel/trace/trace_probe.h +++ b/kernel/trace/trace_probe.h @@ -515,7 +515,8 @@ extern int traceprobe_define_arg_fields( C(BAD_HYPHEN, "Failed to parse single hyphen. Forgot '>'?"), \ C(NO_BTF_FIELD, "This field is not found."), \ C(BAD_BTF_TID, "Failed to get BTF type info."),\ - C(BAD_TYPE4STR, "This type does not fit for string."), + C(BAD_TYPE4STR, "This type does not fit for string."),\ + C(NEED_STRING_TYPE, "$comm and immediate-string only accepts string type"),
#undef C #define C(a, b) TP_ERR_##a