Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
Merge tag 'probes-fixes-v6.6-rc6.2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace
Pull probes fixes from Masami Hiramatsu:
- kprobe-events: Fix kprobe events to reject if the attached symbol is
not unique name because it may not the function which the user want
to attach to. (User can attach a probe to such symbol using the
nearest unique symbol + offset.)
- selftest: Add a testcase to ensure the kprobe event rejects non
unique symbol correctly.
* tag 'probes-fixes-v6.6-rc6.2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
selftests/ftrace: Add new test case which checks non unique symbol
tracing/kprobes: Return EADDRNOTAVAIL when func matches several symbols
+77
+63
kernel/trace/trace_kprobe.c
+63
kernel/trace/trace_kprobe.c
···
705
705
.priority = 1 /* Invoked after kprobe module callback */
706
706
};
707
707
708
+
static int count_symbols(void *data, unsigned long unused)
709
+
{
710
+
unsigned int *count = data;
711
+
712
+
(*count)++;
713
+
714
+
return 0;
715
+
}
716
+
717
+
static unsigned int number_of_same_symbols(char *func_name)
718
+
{
719
+
unsigned int count;
720
+
721
+
count = 0;
722
+
kallsyms_on_each_match_symbol(count_symbols, func_name, &count);
723
+
724
+
return count;
725
+
}
726
+
708
727
static int __trace_kprobe_create(int argc, const char *argv[])
709
728
{
710
729
/*
···
852
833
if (ret == -EINVAL && is_return) {
853
834
trace_probe_log_err(0, BAD_RETPROBE);
854
835
goto parse_error;
836
+
}
837
+
}
838
+
839
+
if (symbol && !strchr(symbol, ':')) {
840
+
unsigned int count;
841
+
842
+
count = number_of_same_symbols(symbol);
843
+
if (count > 1) {
844
+
/*
845
+
* Users should use ADDR to remove the ambiguity of
846
+
* using KSYM only.
847
+
*/
848
+
trace_probe_log_err(0, NON_UNIQ_SYMBOL);
849
+
ret = -EADDRNOTAVAIL;
850
+
851
+
goto error;
852
+
} else if (count == 0) {
853
+
/*
854
+
* We can return ENOENT earlier than when register the
855
+
* kprobe.
856
+
*/
857
+
trace_probe_log_err(0, BAD_PROBE_ADDR);
858
+
ret = -ENOENT;
859
+
860
+
goto error;
855
861
}
856
862
}
857
863
···
1739
1695
}
1740
1696
1741
1697
#ifdef CONFIG_PERF_EVENTS
1698
+
1742
1699
/* create a trace_kprobe, but don't add it to global lists */
1743
1700
struct trace_event_call *
1744
1701
create_local_trace_kprobe(char *func, void *addr, unsigned long offs,
···
1749
1704
struct trace_kprobe *tk;
1750
1705
int ret;
1751
1706
char *event;
1707
+
1708
+
if (func) {
1709
+
unsigned int count;
1710
+
1711
+
count = number_of_same_symbols(func);
1712
+
if (count > 1)
1713
+
/*
1714
+
* Users should use addr to remove the ambiguity of
1715
+
* using func only.
1716
+
*/
1717
+
return ERR_PTR(-EADDRNOTAVAIL);
1718
+
else if (count == 0)
1719
+
/*
1720
+
* We can return ENOENT earlier than when register the
1721
+
* kprobe.
1722
+
*/
1723
+
return ERR_PTR(-ENOENT);
1724
+
}
1752
1725
1753
1726
/*
1754
1727
* local trace_kprobes are not added to dyn_event, so they are never
+1
kernel/trace/trace_probe.h
+1
kernel/trace/trace_probe.h
···
450
450
C(BAD_MAXACT, "Invalid maxactive number"), \
451
451
C(MAXACT_TOO_BIG, "Maxactive is too big"), \
452
452
C(BAD_PROBE_ADDR, "Invalid probed address or symbol"), \
453
+
C(NON_UNIQ_SYMBOL, "The symbol is not unique"), \
453
454
C(BAD_RETPROBE, "Retprobe address must be an function entry"), \
454
455
C(NO_TRACEPOINT, "Tracepoint is not found"), \
455
456
C(BAD_ADDR_SUFFIX, "Invalid probed address suffix"), \
+13
tools/testing/selftests/ftrace/test.d/kprobe/kprobe_non_uniq_symbol.tc
+13
tools/testing/selftests/ftrace/test.d/kprobe/kprobe_non_uniq_symbol.tc
···
1
+
#!/bin/sh
2
+
# SPDX-License-Identifier: GPL-2.0
3
+
# description: Test failure of registering kprobe on non unique symbol
4
+
# requires: kprobe_events
5
+
6
+
SYMBOL='name_show'
7
+
8
+
# We skip this test on kernel where SYMBOL is unique or does not exist.
9
+
if [ "$(grep -c -E "[[:alnum:]]+ t ${SYMBOL}" /proc/kallsyms)" -le '1' ]; then
10
+
exit_unsupported
11
+
fi
12
+
13
+
! echo "p:test_non_unique ${SYMBOL}" > kprobe_events