From e09e28671cda63e6308b31798b997639120e2a21 Mon Sep 17 00:00:00 2001 From: Amey Telawane Date: Wed, 3 May 2017 15:41:14 +0530 Subject: tracing: Use strlcpy() instead of strcpy() in __trace_find_cmdline() Strcpy is inherently not safe, and strlcpy() should be used instead. __trace_find_cmdline() uses strcpy() because the comms saved must have a terminating nul character, but it doesn't hurt to add the extra protection of using strlcpy() instead of strcpy(). Link: http://lkml.kernel.org/r/1493806274-13936-1-git-send-email-amit.pundir@linaro.org Signed-off-by: Amey Telawane [AmitP: Cherry-picked this commit from CodeAurora kernel/msm-3.10 https://source.codeaurora.org/quic/la/kernel/msm-3.10/commit/?id=2161ae9a70b12cf18ac8e5952a20161ffbccb477] Signed-off-by: Amit Pundir [ Updated change log and removed the "- 1" from len parameter ] Signed-off-by: Steven Rostedt (VMware) --- kernel/trace/trace.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'kernel') diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 80eda7d254ed..4ad4420b33d6 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -1976,7 +1976,7 @@ static void __trace_find_cmdline(int pid, char comm[]) map = savedcmd->map_pid_to_cmdline[pid]; if (map != NO_CMDLINE_MAP) - strcpy(comm, get_saved_cmdlines(map)); + strlcpy(comm, get_saved_cmdlines(map), TASK_COMM_LEN); else strcpy(comm, "<...>"); } -- cgit v1.2.3 From 31805c90521ea75dfa3d016fc94f581da6a40fee Mon Sep 17 00:00:00 2001 From: Dan Carpenter Date: Fri, 31 Mar 2017 18:21:30 +0300 Subject: ftrace: Remove an unneeded condition We know that "mod_matches" is true here so there is no need to check again. Link: http://lkml.kernel.org/r/20170331152130.GA4947@mwanda Signed-off-by: Dan Carpenter Signed-off-by: Steven Rostedt (VMware) --- kernel/trace/ftrace.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'kernel') diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index 00077a57b746..84286d347cd8 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -3644,7 +3644,7 @@ ftrace_match_record(struct dyn_ftrace *rec, struct ftrace_glob *func_g, return 0; } - if (mod_matches && exclude_mod) + if (exclude_mod) return 0; func_match: -- cgit v1.2.3 From 77c0eddeeeee14bf0fb0c0bb97e782981bbcf084 Mon Sep 17 00:00:00 2001 From: "Steven Rostedt (VMware)" Date: Wed, 3 May 2017 11:41:44 -0400 Subject: ftrace: Simplify ftrace_match_record() even more Dan Carpenter sent a patch to remove a check in ftrace_match_record() because the logic of the code made the check redundant. I looked deeper into the code, and made the following logic table, with the three variables and the result of the original code. modname mod_matches exclude_mod result ------- ----------- ----------- ------ 0 0 0 return 0 0 0 1 func_match 0 1 * < cannot exist > 1 0 0 return 0 1 0 1 func_match 1 1 0 func_match 1 1 1 return 0 Notice that when mod_matches == exclude mod, the result is always to return 0, and when mod_matches != exclude_mod, then the result is to test the function. This means we only need test if mod_matches is equal to exclude_mod. Cc: Dan Carpenter Signed-off-by: Steven Rostedt (VMware) --- kernel/trace/ftrace.c | 20 +++++++++----------- 1 file changed, 9 insertions(+), 11 deletions(-) (limited to 'kernel') diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index 84286d347cd8..39dca4e86a94 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -3631,22 +3631,20 @@ ftrace_match_record(struct dyn_ftrace *rec, struct ftrace_glob *func_g, /* blank module name to match all modules */ if (!mod_g->len) { /* blank module globbing: modname xor exclude_mod */ - if ((!exclude_mod) != (!modname)) + if (!exclude_mod != !modname) goto func_match; return 0; } - /* not matching the module */ - if (!modname || !mod_matches) { - if (exclude_mod) - goto func_match; - else - return 0; - } - - if (exclude_mod) + /* + * exclude_mod is set to trace everything but the given + * module. If it is set and the module matches, then + * return 0. If it is not set, and the module doesn't match + * also return 0. Otherwise, check the function to see if + * that matches. + */ + if (!mod_matches == !exclude_mod) return 0; - func_match: /* blank search means to match all funcs in the mod */ if (!func_g->len) -- cgit v1.2.3