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Patch "tracing: probeevent: Fix to support minus offset from symbol" has been added to the 4.15-stable tree

PATCH [email protected] 1 participant 1 message Mar 25, 2018

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This is a note to let you know that I've just added the patch titled

tracing: probeevent: Fix to support minus offset from symbol

to the 4.15-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:
tracing-probeevent-fix-to-support-minus-offset-from-symbol.patch
and it can be found in the queue-4.15 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

Quoted 1 line

From c5d343b6b7badd1f5fe0873eff2e8d63a193e732 Mon Sep 17 00:00:00 2001

From: Masami Hiramatsu <[email protected]>
Date: Sat, 17 Mar 2018 21:38:10 +0900
Subject: tracing: probeevent: Fix to support minus offset from symbol

From: Masami Hiramatsu <[email protected]>

commit c5d343b6b7badd1f5fe0873eff2e8d63a193e732 upstream.

In Documentation/trace/kprobetrace.txt, it says

@SYM[+|-offs] : Fetch memory at SYM +|- offs (SYM should be a data symbol)

However, the parser doesn't parse minus offset correctly, since commit 2fba0c8867af ("tracing/kprobes: Fix probe offset to be unsigned") drops minus ("-") offset support for kprobe probe address usage.

This fixes the traceprobe_split_symbol_offset() to parse minus offset again with checking the offset range, and add a minus offset check in kprobe probe address usage.

Link http://lkml.kernel.org/r/152129028983.31874.13419301530285775521.stgit@devbox open here
Cc Ingo Molnar <[email protected]>
Cc Tom Zanussi <[email protected]>
Cc Arnaldo Carvalho de Melo <[email protected]>
Cc Ravi Bangoria <[email protected]>
Cc [email protected]
Fixes 2fba0c8867af ("tracing/kprobes: Fix probe offset to be unsigned")
Acked-by Namhyung Kim <[email protected]>
Signed-off-by Masami Hiramatsu <[email protected]>
Signed-off-by Steven Rostedt (VMware) <[email protected]>
Signed-off-by Greg Kroah-Hartman <[email protected]>
---
 kernel/trace/trace_kprobe.c |    4 ++--
 kernel/trace/trace_probe.c  |    8 +++-----
 kernel/trace/trace_probe.h  |    2 +-
 3 files changed, 6 insertions(+), 8 deletions(-)
kernel/trace/trace_kprobe.c +2 -2
@@ -635,7 +635,7 @@ static int create_trace_kprobe(int argc,
 	char *symbol = NULL, *event = NULL, *group = NULL;
 	int maxactive = 0;
 	char *arg;
-	unsigned long offset = 0;
+	long offset = 0;
 	void *addr = NULL;
 	char buf[MAX_EVENT_NAME_LEN];
 

@@ -723,7 +723,7 @@ static int create_trace_kprobe(int argc,
 		symbol = argv[1];
 		/* TODO: support .init module functions */
 		ret = traceprobe_split_symbol_offset(symbol, &offset);
-		if (ret) {
+		if (ret || offset < 0 || offset > UINT_MAX) {
 			pr_info("Failed to parse either an address or a symbol.\n");
 			return ret;
 		}
kernel/trace/trace_probe.c +3 -5
@@ -320,7 +320,7 @@ static fetch_func_t get_fetch_size_funct
 }
 
 /* Split symbol and offset. */
-int traceprobe_split_symbol_offset(char *symbol, unsigned long *offset)
+int traceprobe_split_symbol_offset(char *symbol, long *offset)
 {
 	char *tmp;
 	int ret;

@@ -328,13 +328,11 @@ int traceprobe_split_symbol_offset(char
 	if (!offset)
 		return -EINVAL;
 
-	tmp = strchr(symbol, '+');
+	tmp = strpbrk(symbol, "+-");
 	if (tmp) {
-		/* skip sign because kstrtoul doesn't accept '+' */
-		ret = kstrtoul(tmp + 1, 0, offset);
+		ret = kstrtol(tmp, 0, offset);
 		if (ret)
 			return ret;
-
 		*tmp = '\0';
 	} else
 		*offset = 0;
kernel/trace/trace_probe.h +1 -1
@@ -353,7 +353,7 @@ extern int traceprobe_conflict_field_nam
 extern void traceprobe_update_arg(struct probe_arg *arg);
 extern void traceprobe_free_probe_arg(struct probe_arg *arg);
 
-extern int traceprobe_split_symbol_offset(char *symbol, unsigned long *offset);
+extern int traceprobe_split_symbol_offset(char *symbol, long *offset);
 
 /* Sum up total data length for dynamic arraies (strings) */
 static nokprobe_inline int

Patches currently in stable-queue which might be from [email protected] are

queue-4.15/tracing-probeevent-fix-to-support-minus-offset-from-symbol.patch