Commit-ID: 6143c6fb1e8f9bde9c434038f7548a19d36b55e7 Gitweb: https://git.kernel.org/tip/6143c6fb1e8f9bde9c434038f7548a19d36b55e7 Author: Masami Hiramatsu <[email protected]> AuthorDate: Wed, 13 Feb 2019 01:13:12 +0900 Committer: Ingo Molnar <[email protected]> CommitDate: Wed, 13 Feb 2019 08:16:40 +0100
kprobes: Search non-suffixed symbol in blacklist Newer GCC versions can generate some different instances of a function with suffixed symbols if the function is optimized and only has a part of that. (e.g. .constprop, .part etc.) In this case, it is not enough to check the entry of kprobe blacklist because it only records non-suffixed symbol address. To fix this issue, search non-suffixed symbol in blacklist if given address is within a symbol which has a suffix. Note that this can cause false positive cases if a kprobe-safe function is optimized to suffixed instance and has same name symbol which is blacklisted. But I would like to chose a fail-safe design for this issue. Signed-off-by: Masami Hiramatsu <[email protected]> Reviewed-by: Steven Rostedt (VMware) <[email protected]> Cc: Alexander Shishkin <[email protected]> Cc: Andrea Righi <[email protected]> Cc: Arnaldo Carvalho de Melo <[email protected]> Cc: Jiri Olsa <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Mathieu Desnoyers <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Steven Rostedt <[email protected]> Cc: Thomas Gleixner <[email protected]> Link: http://lkml.kernel.org/r/154998799234.31052.6136378903570418008.stgit@devbox Signed-off-by: Ingo Molnar <[email protected]> --- kernel/kprobes.c | 21 ++++++++++++++++++++- 1 file changed, 20 insertions(+), 1 deletion(-) diff --git a/kernel/kprobes.c b/kernel/kprobes.c index f4ddfdd2d07e..c83e54727131 100644 --- a/kernel/kprobes.c +++ b/kernel/kprobes.c @@ -1396,7 +1396,7 @@ bool __weak arch_within_kprobe_blacklist(unsigned long addr) addr < (unsigned long)__kprobes_text_end; } -bool within_kprobe_blacklist(unsigned long addr) +static bool __within_kprobe_blacklist(unsigned long addr) { struct kprobe_blacklist_entry *ent; @@ -1410,7 +1410,26 @@ bool within_kprobe_blacklist(unsigned long addr) if (addr >= ent->start_addr && addr < ent->end_addr) return true; } + return false; +} +bool within_kprobe_blacklist(unsigned long addr) +{ + char symname[KSYM_NAME_LEN], *p; + + if (__within_kprobe_blacklist(addr)) + return true; + + /* Check if the address is on a suffixed-symbol */ + if (!lookup_symbol_name(addr, symname)) { + p = strchr(symname, '.'); + if (!p) + return false; + *p = '\0'; + addr = (unsigned long)kprobe_lookup_name(symname, 0); + if (addr) + return __within_kprobe_blacklist(addr); + } return false; }
