From bd7c606e6724adc01009d8551b7666a8bcb64a5c Mon Sep 17 00:00:00 2001 From: Masami Hiramatsu Date: Sat, 17 Mar 2018 21:38:10 +0900 Subject: [PATCH] tracing: probeevent: Fix to support minus offset from symbol 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 Cc: Ingo Molnar Cc: Tom Zanussi Cc: Arnaldo Carvalho de Melo Cc: Ravi Bangoria Fixes: 2fba0c8867af ("tracing/kprobes: Fix probe offset to be unsigned") Acked-by: Namhyung Kim Signed-off-by: Masami Hiramatsu Signed-off-by: Steven Rostedt (VMware) [bwh: Backported to 3.2: adjust filename, context] Signed-off-by: Ben Hutchings --- kernel/trace/trace_kprobe.c | 11 +++++------ 1 file changed, 5 insertions(+), 6 deletions(-) diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c index 2ec1a389a939..367b36511018 100644 --- a/kernel/trace/trace_kprobe.c +++ b/kernel/trace/trace_kprobe.c @@ -920,7 +920,7 @@ static struct notifier_block trace_probe_module_nb = { }; /* Split symbol and offset. */ -static int split_symbol_offset(char *symbol, unsigned long *offset) +static int split_symbol_offset(char *symbol, long *offset) { char *tmp; int ret; @@ -928,10 +928,9 @@ static int split_symbol_offset(char *symbol, unsigned long *offset) if (!offset) return -EINVAL; - tmp = strchr(symbol, '+'); + tmp = strpbrk(symbol, "+-"); if (tmp) { - /* skip sign because strict_strtol doesn't accept '+' */ - ret = strict_strtoul(tmp + 1, 0, offset); + ret = kstrtol(tmp, 0, offset); if (ret) return ret; *tmp = '\0'; @@ -1165,7 +1164,7 @@ static int create_trace_probe(int argc, char **argv) int is_return = 0, is_delete = 0; char *symbol = NULL, *event = NULL, *group = NULL; char *arg; - unsigned long offset = 0; + long offset = 0; void *addr = NULL; char buf[MAX_EVENT_NAME_LEN]; @@ -1238,7 +1237,7 @@ static int create_trace_probe(int argc, char **argv) symbol = argv[1]; /* TODO: support .init module functions */ ret = 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; } -- 2.39.2