From 2f7c68cb55ecb7331f2381deb497c27155f32faf Mon Sep 17 00:00:00 2001
From: hc <hc@nodka.com>
Date: Wed, 03 Jan 2024 09:43:39 +0000
Subject: [PATCH] update kernel to 5.10.198
---
kernel/tools/testing/selftests/rseq/rseq.c | 33 ++++++++++++++++++++++++++-------
1 files changed, 26 insertions(+), 7 deletions(-)
diff --git a/kernel/tools/testing/selftests/rseq/rseq.c b/kernel/tools/testing/selftests/rseq/rseq.c
index 986b945..e20191f 100644
--- a/kernel/tools/testing/selftests/rseq/rseq.c
+++ b/kernel/tools/testing/selftests/rseq/rseq.c
@@ -29,12 +29,22 @@
#include <dlfcn.h>
#include <stddef.h>
+#include <linux/compiler.h>
+
#include "../kselftest.h"
#include "rseq.h"
-static const ptrdiff_t *libc_rseq_offset_p;
-static const unsigned int *libc_rseq_size_p;
-static const unsigned int *libc_rseq_flags_p;
+/*
+ * Define weak versions to play nice with binaries that are statically linked
+ * against a libc that doesn't support registering its own rseq.
+ */
+__weak ptrdiff_t __rseq_offset;
+__weak unsigned int __rseq_size;
+__weak unsigned int __rseq_flags;
+
+static const ptrdiff_t *libc_rseq_offset_p = &__rseq_offset;
+static const unsigned int *libc_rseq_size_p = &__rseq_size;
+static const unsigned int *libc_rseq_flags_p = &__rseq_flags;
/* Offset from the thread pointer to the rseq area. */
ptrdiff_t rseq_offset;
@@ -108,10 +118,19 @@
static __attribute__((constructor))
void rseq_init(void)
{
- libc_rseq_offset_p = dlsym(RTLD_NEXT, "__rseq_offset");
- libc_rseq_size_p = dlsym(RTLD_NEXT, "__rseq_size");
- libc_rseq_flags_p = dlsym(RTLD_NEXT, "__rseq_flags");
- if (libc_rseq_size_p && libc_rseq_offset_p && libc_rseq_flags_p) {
+ /*
+ * If the libc's registered rseq size isn't already valid, it may be
+ * because the binary is dynamically linked and not necessarily due to
+ * libc not having registered a restartable sequence. Try to find the
+ * symbols if that's the case.
+ */
+ if (!*libc_rseq_size_p) {
+ libc_rseq_offset_p = dlsym(RTLD_NEXT, "__rseq_offset");
+ libc_rseq_size_p = dlsym(RTLD_NEXT, "__rseq_size");
+ libc_rseq_flags_p = dlsym(RTLD_NEXT, "__rseq_flags");
+ }
+ if (libc_rseq_size_p && libc_rseq_offset_p && libc_rseq_flags_p &&
+ *libc_rseq_size_p != 0) {
/* rseq registration owned by glibc */
rseq_offset = *libc_rseq_offset_p;
rseq_size = *libc_rseq_size_p;
--
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