lkml.org 
[lkml]   [2018]   [Apr]   [6]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH 3.18 14/93] tracing: probeevent: Fix to support minus offset from symbol
Date
3.18-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Masami Hiramatsu <mhiramat@kernel.org>

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 <mingo@redhat.com>
Cc: Tom Zanussi <tom.zanussi@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Ravi Bangoria <ravi.bangoria@linux.vnet.ibm.com>
Cc: stable@vger.kernel.org
Fixes: 2fba0c8867af ("tracing/kprobes: Fix probe offset to be unsigned")
Acked-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
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(-)

--- a/kernel/trace/trace_kprobe.c
+++ b/kernel/trace/trace_kprobe.c
@@ -611,7 +611,7 @@ static int create_trace_kprobe(int argc,
bool is_return = false, is_delete = false;
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];

@@ -679,7 +679,7 @@ 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;
}
--- a/kernel/trace/trace_probe.c
+++ b/kernel/trace/trace_probe.c
@@ -291,7 +291,7 @@ 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;
@@ -299,13 +299,11 @@ 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;
--- a/kernel/trace/trace_probe.h
+++ b/kernel/trace/trace_probe.h
@@ -341,7 +341,7 @@ 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);

extern ssize_t traceprobe_probes_write(struct file *file,
const char __user *buffer, size_t count, loff_t *ppos,

\
 
 \ /
  Last update: 2018-04-06 17:29    [W:0.314 / U:6.220 seconds]
©2003-2018 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site