Newer gcc 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 mhiramat@kernel.org --- kernel/kprobes.c | 21 ++++++++++++++++++++- 1 file changed, 20 insertions(+), 1 deletion(-)
diff --git a/kernel/kprobes.c b/kernel/kprobes.c index e8c76164f541..faa519f07aad 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; }