From: "tip-bot2 for Borislav Petkov" <tip-bot2@linutronix.de>
To: linux-tip-commits@vger.kernel.org
Cc: Linus Torvalds <torvalds@linux-foundation.org>,
Borislav Petkov <bp@suse.de>,
Masami Hiramatsu <mhiramat@kernel.org>,
x86@kernel.org, linux-kernel@vger.kernel.org
Subject: [tip: x86/misc] x86/insn: Use get_unaligned() instead of memcpy()
Date: Mon, 04 Oct 2021 09:48:44 -0000 [thread overview]
Message-ID: <163334092477.25758.5874478380909816941.tip-bot2@tip-bot2> (raw)
In-Reply-To: <YVSsIkj9Z29TyUjE@zn.tnic>
The following commit has been merged into the x86/misc branch of tip:
Commit-ID: a1be25a30cf654b3314bc7b26db5e52716833144
Gitweb: https://git.kernel.org/tip/a1be25a30cf654b3314bc7b26db5e52716833144
Author: Borislav Petkov <bp@suse.de>
AuthorDate: Wed, 29 Sep 2021 16:37:53 +02:00
Committer: Borislav Petkov <bp@suse.de>
CommitterDate: Mon, 04 Oct 2021 11:11:58 +02:00
x86/insn: Use get_unaligned() instead of memcpy()
Use get_unaligned() instead of memcpy() to access potentially unaligned
memory, which, when accessed through a pointer, leads to undefined
behavior. get_unaligned() describes much better what is happening there
anyway even if memcpy() does the job.
No functional changes.
Fixes: 5ba1071f7554 ("x86/insn, tools/x86: Fix undefined behavior due to potential unaligned accesses")
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Link: https://lkml.kernel.org/r/YVSsIkj9Z29TyUjE@zn.tnic
---
arch/x86/lib/insn.c | 5 +++--
tools/arch/x86/lib/insn.c | 5 +++--
tools/include/asm-generic/unaligned.h | 23 +++++++++++++++++++++++
3 files changed, 29 insertions(+), 4 deletions(-)
create mode 100644 tools/include/asm-generic/unaligned.h
diff --git a/arch/x86/lib/insn.c b/arch/x86/lib/insn.c
index c565def..55e371c 100644
--- a/arch/x86/lib/insn.c
+++ b/arch/x86/lib/insn.c
@@ -13,6 +13,7 @@
#endif
#include <asm/inat.h> /*__ignore_sync_check__ */
#include <asm/insn.h> /* __ignore_sync_check__ */
+#include <asm/unaligned.h> /* __ignore_sync_check__ */
#include <linux/errno.h>
#include <linux/kconfig.h>
@@ -37,10 +38,10 @@
((insn)->next_byte + sizeof(t) + n <= (insn)->end_kaddr)
#define __get_next(t, insn) \
- ({ t r; memcpy(&r, insn->next_byte, sizeof(t)); insn->next_byte += sizeof(t); leXX_to_cpu(t, r); })
+ ({ t r = get_unaligned((t *)(insn)->next_byte); (insn)->next_byte += sizeof(t); leXX_to_cpu(t, r); })
#define __peek_nbyte_next(t, insn, n) \
- ({ t r; memcpy(&r, (insn)->next_byte + n, sizeof(t)); leXX_to_cpu(t, r); })
+ ({ t r = get_unaligned((t *)(insn)->next_byte + n); leXX_to_cpu(t, r); })
#define get_next(t, insn) \
({ if (unlikely(!validate_next(t, insn, 0))) goto err_out; __get_next(t, insn); })
diff --git a/tools/arch/x86/lib/insn.c b/tools/arch/x86/lib/insn.c
index 7976994..8fd63a0 100644
--- a/tools/arch/x86/lib/insn.c
+++ b/tools/arch/x86/lib/insn.c
@@ -13,6 +13,7 @@
#endif
#include "../include/asm/inat.h" /* __ignore_sync_check__ */
#include "../include/asm/insn.h" /* __ignore_sync_check__ */
+#include "../include/asm-generic/unaligned.h" /* __ignore_sync_check__ */
#include <linux/errno.h>
#include <linux/kconfig.h>
@@ -37,10 +38,10 @@
((insn)->next_byte + sizeof(t) + n <= (insn)->end_kaddr)
#define __get_next(t, insn) \
- ({ t r; memcpy(&r, insn->next_byte, sizeof(t)); insn->next_byte += sizeof(t); leXX_to_cpu(t, r); })
+ ({ t r = get_unaligned((t *)(insn)->next_byte); (insn)->next_byte += sizeof(t); leXX_to_cpu(t, r); })
#define __peek_nbyte_next(t, insn, n) \
- ({ t r; memcpy(&r, (insn)->next_byte + n, sizeof(t)); leXX_to_cpu(t, r); })
+ ({ t r = get_unaligned((t *)(insn)->next_byte + n); leXX_to_cpu(t, r); })
#define get_next(t, insn) \
({ if (unlikely(!validate_next(t, insn, 0))) goto err_out; __get_next(t, insn); })
diff --git a/tools/include/asm-generic/unaligned.h b/tools/include/asm-generic/unaligned.h
new file mode 100644
index 0000000..47387c6
--- /dev/null
+++ b/tools/include/asm-generic/unaligned.h
@@ -0,0 +1,23 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * Copied from the kernel sources to tools/perf/:
+ */
+
+#ifndef __TOOLS_LINUX_ASM_GENERIC_UNALIGNED_H
+#define __TOOLS_LINUX_ASM_GENERIC_UNALIGNED_H
+
+#define __get_unaligned_t(type, ptr) ({ \
+ const struct { type x; } __packed *__pptr = (typeof(__pptr))(ptr); \
+ __pptr->x; \
+})
+
+#define __put_unaligned_t(type, val, ptr) do { \
+ struct { type x; } __packed *__pptr = (typeof(__pptr))(ptr); \
+ __pptr->x = (val); \
+} while (0)
+
+#define get_unaligned(ptr) __get_unaligned_t(typeof(*(ptr)), (ptr))
+#define put_unaligned(val, ptr) __put_unaligned_t(typeof(*(ptr)), (val), (ptr))
+
+#endif /* __TOOLS_LINUX_ASM_GENERIC_UNALIGNED_H */
+
next prev parent reply other threads:[~2021-10-04 9:48 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-09-26 10:30 [GIT pull] irq/urgent for v5.15-rc3 Thomas Gleixner
2021-09-26 10:30 ` [GIT pull] timers/urgent " Thomas Gleixner
2021-09-26 17:27 ` pr-tracker-bot
2021-09-26 10:30 ` [GIT pull] x86/urgent " Thomas Gleixner
2021-09-26 17:21 ` Linus Torvalds
2021-09-26 18:15 ` Borislav Petkov
2021-09-26 19:10 ` Linus Torvalds
2021-09-28 17:56 ` Borislav Petkov
2021-09-28 20:13 ` Linus Torvalds
2021-09-28 20:41 ` Borislav Petkov
2021-09-28 22:44 ` Linus Torvalds
2021-09-29 18:10 ` [PATCH] x86/insn: Use get_unaligned() instead of memcpy() Borislav Petkov
2021-09-30 0:00 ` Masami Hiramatsu
2021-10-04 9:48 ` tip-bot2 for Borislav Petkov [this message]
2021-10-06 10:02 ` [tip: x86/misc] " tip-bot2 for Borislav Petkov
2021-09-26 17:27 ` [GIT pull] x86/urgent for v5.15-rc3 pr-tracker-bot
2021-09-26 17:27 ` [GIT pull] irq/urgent " pr-tracker-bot
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