4.4-stable review patch. If anyone has any objections, please let me know.
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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@devbo...
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 @@ -599,7 +599,7 @@ 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];
@@ -667,7 +667,7 @@ 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 @@ -293,7 +293,7 @@ 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; @@ -301,13 +301,11 @@ 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 @@ -335,7 +335,7 @@ 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,