diff mbox series

[PATCHv3,bpf,2/4] ftrace: Keep address offset in ftrace_lookup_symbols

Message ID 20220615112118.497303-3-jolsa@kernel.org (mailing list archive)
State Accepted
Commit eb1b2985fe5c5f02e43e4c0d47bbe7ed835007f3
Delegated to: BPF
Headers show
Series bpf: Fix cookie values for kprobe multi | expand

Checks

Context Check Description
netdev/tree_selection success Clearly marked for bpf
netdev/fixes_present success Fixes tag present in non-next series
netdev/subject_prefix success Link
netdev/cover_letter success Series has a cover letter
netdev/patch_count success Link
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 95 this patch: 95
netdev/cc_maintainers warning 2 maintainers not CCed: kpsingh@kernel.org mingo@redhat.com
netdev/build_clang success Errors and warnings before: 35 this patch: 35
netdev/module_param success Was 0 now: 0
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/check_selftest success No net selftest shell script
netdev/verify_fixes success Fixes tag looks correct
netdev/build_allmodconfig_warn success Errors and warnings before: 95 this patch: 95
netdev/checkpatch warning WARNING: line length of 86 exceeds 80 columns
netdev/kdoc success Errors and warnings before: 25 this patch: 25
netdev/source_inline success Was 0 now: 0
bpf/vmtest-bpf-PR fail PR summary
bpf/vmtest-bpf-VM_Test-1 fail Logs for Kernel LATEST on ubuntu-latest with gcc
bpf/vmtest-bpf-VM_Test-2 fail Logs for Kernel LATEST on ubuntu-latest with llvm-15
bpf/vmtest-bpf-VM_Test-3 fail Logs for Kernel LATEST on z15 with gcc

Commit Message

Jiri Olsa June 15, 2022, 11:21 a.m. UTC 
We want to store the resolved address on the same index as
the symbol string, because that's the user (bpf kprobe link)
code assumption.

Also making sure we don't store duplicates that might be
present in kallsyms.

Acked-by: Song Liu <songliubraving@fb.com>
Acked-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Fixes: bed0d9a50dac ("ftrace: Add ftrace_lookup_symbols function")
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
---
 kernel/trace/ftrace.c | 13 +++++++++++--
 1 file changed, 11 insertions(+), 2 deletions(-)
diff mbox series

Patch

diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index e750fe141a60..601ccf1b2f09 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -8029,15 +8029,23 @@  static int kallsyms_callback(void *data, const char *name,
 			     struct module *mod, unsigned long addr)
 {
 	struct kallsyms_data *args = data;
+	const char **sym;
+	int idx;
 
-	if (!bsearch(&name, args->syms, args->cnt, sizeof(*args->syms), symbols_cmp))
+	sym = bsearch(&name, args->syms, args->cnt, sizeof(*args->syms), symbols_cmp);
+	if (!sym)
+		return 0;
+
+	idx = sym - args->syms;
+	if (args->addrs[idx])
 		return 0;
 
 	addr = ftrace_location(addr);
 	if (!addr)
 		return 0;
 
-	args->addrs[args->found++] = addr;
+	args->addrs[idx] = addr;
+	args->found++;
 	return args->found == args->cnt ? 1 : 0;
 }
 
@@ -8062,6 +8070,7 @@  int ftrace_lookup_symbols(const char **sorted_syms, size_t cnt, unsigned long *a
 	struct kallsyms_data args;
 	int err;
 
+	memset(addrs, 0, sizeof(*addrs) * cnt);
 	args.addrs = addrs;
 	args.syms = sorted_syms;
 	args.cnt = cnt;