releases/4.14.31/tracing-probeevent-fix-to-support-minus-offset-from-symbol.patch

   1 From c5d343b6b7badd1f5fe0873eff2e8d63a193e732 Mon Sep 17 00:00:00 2001
   2 From: Masami Hiramatsu <mhiramat@kernel.org>
   3 Date: Sat, 17 Mar 2018 21:38:10 +0900
   4 Subject: tracing: probeevent: Fix to support minus offset from symbol
   5
   6 From: Masami Hiramatsu <mhiramat@kernel.org>
   7
   8 commit c5d343b6b7badd1f5fe0873eff2e8d63a193e732 upstream.
   9
  10 In Documentation/trace/kprobetrace.txt, it says
  11
  12  @SYM[+|-offs] : Fetch memory at SYM +|- offs (SYM should be a data symbol)
  13
  14 However, the parser doesn't parse minus offset correctly, since
  15 commit 2fba0c8867af ("tracing/kprobes: Fix probe offset to be
  16 unsigned") drops minus ("-") offset support for kprobe probe
  17 address usage.
  18
  19 This fixes the traceprobe_split_symbol_offset() to parse minus
  20 offset again with checking the offset range, and add a minus
  21 offset check in kprobe probe address usage.
  22
  23 Link: http://lkml.kernel.org/r/152129028983.31874.13419301530285775521.stgit@devbox
  24
  25 Cc: Ingo Molnar <mingo@redhat.com>
  26 Cc: Tom Zanussi <tom.zanussi@linux.intel.com>
  27 Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
  28 Cc: Ravi Bangoria <ravi.bangoria@linux.vnet.ibm.com>
  29 Cc: stable@vger.kernel.org
  30 Fixes: 2fba0c8867af ("tracing/kprobes: Fix probe offset to be unsigned")
  31 Acked-by: Namhyung Kim <namhyung@kernel.org>
  32 Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
  33 Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
  34 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
  35
  36 ---
  37  kernel/trace/trace_kprobe.c |    4 ++--
  38  kernel/trace/trace_probe.c  |    8 +++-----
  39  kernel/trace/trace_probe.h  |    2 +-
  40  3 files changed, 6 insertions(+), 8 deletions(-)
  41
  42 --- a/kernel/trace/trace_kprobe.c
  43 +++ b/kernel/trace/trace_kprobe.c
  44 @@ -635,7 +635,7 @@ static int create_trace_kprobe(int argc,
  45         char *symbol = NULL, *event = NULL, *group = NULL;
  46         int maxactive = 0;
  47         char *arg;
  48 -       unsigned long offset = 0;
  49 +       long offset = 0;
  50         void *addr = NULL;
  51         char buf[MAX_EVENT_NAME_LEN];
  52
  53 @@ -723,7 +723,7 @@ static int create_trace_kprobe(int argc,
  54                 symbol = argv[1];
  55                 /* TODO: support .init module functions */
  56                 ret = traceprobe_split_symbol_offset(symbol, &offset);
  57 -               if (ret) {
  58 +               if (ret || offset < 0 || offset > UINT_MAX) {
  59                         pr_info("Failed to parse either an address or a symbol.\n");
  60                         return ret;
  61                 }
  62 --- a/kernel/trace/trace_probe.c
  63 +++ b/kernel/trace/trace_probe.c
  64 @@ -320,7 +320,7 @@ static fetch_func_t get_fetch_size_funct
  65  }
  66
  67  /* Split symbol and offset. */
  68 -int traceprobe_split_symbol_offset(char *symbol, unsigned long *offset)
  69 +int traceprobe_split_symbol_offset(char *symbol, long *offset)
  70  {
  71         char *tmp;
  72         int ret;
  73 @@ -328,13 +328,11 @@ int traceprobe_split_symbol_offset(char
  74         if (!offset)
  75                 return -EINVAL;
  76
  77 -       tmp = strchr(symbol, '+');
  78 +       tmp = strpbrk(symbol, "+-");
  79         if (tmp) {
  80 -               /* skip sign because kstrtoul doesn't accept '+' */
  81 -               ret = kstrtoul(tmp + 1, 0, offset);
  82 +               ret = kstrtol(tmp, 0, offset);
  83                 if (ret)
  84                         return ret;
  85 -
  86                 *tmp = '\0';
  87         } else
  88                 *offset = 0;
  89 --- a/kernel/trace/trace_probe.h
  90 +++ b/kernel/trace/trace_probe.h
  91 @@ -354,7 +354,7 @@ extern int traceprobe_conflict_field_nam
  92  extern void traceprobe_update_arg(struct probe_arg *arg);
  93  extern void traceprobe_free_probe_arg(struct probe_arg *arg);
  94
  95 -extern int traceprobe_split_symbol_offset(char *symbol, unsigned long *offset);
  96 +extern int traceprobe_split_symbol_offset(char *symbol, long *offset);
  97
  98  extern ssize_t traceprobe_probes_write(struct file *file,
  99                 const char __user *buffer, size_t count, loff_t *ppos,