From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: linux-kernel@vger.kernel.org, stable@vger.kernel.org
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
"Peter Zijlstra (Intel)" <peterz@infradead.org>,
Borislav Petkov <bp@suse.de>,
Josh Poimboeuf <jpoimboe@kernel.org>,
Thadeu Lima de Souza Cascardo <cascardo@canonical.com>
Subject: [PATCH 5.15 08/14] x86/ftrace: Use alternative RET encoding
Date: Fri, 19 Aug 2022 17:40:24 +0200 [thread overview]
Message-ID: <20220819153711.948887870@linuxfoundation.org> (raw)
In-Reply-To: <20220819153711.658766010@linuxfoundation.org>
From: Peter Zijlstra <peterz@infradead.org>
commit 1f001e9da6bbf482311e45e48f53c2bd2179e59c upstream.
Use the return thunk in ftrace trampolines, if needed.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Josh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
[cascardo: use memcpy(text_gen_insn) as there is no __text_gen_insn]
Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
arch/x86/kernel/ftrace.c | 9 +++++++--
1 file changed, 7 insertions(+), 2 deletions(-)
--- a/arch/x86/kernel/ftrace.c
+++ b/arch/x86/kernel/ftrace.c
@@ -309,7 +309,7 @@ union ftrace_op_code_union {
} __attribute__((packed));
};
-#define RET_SIZE 1 + IS_ENABLED(CONFIG_SLS)
+#define RET_SIZE (IS_ENABLED(CONFIG_RETPOLINE) ? 5 : 1 + IS_ENABLED(CONFIG_SLS))
static unsigned long
create_trampoline(struct ftrace_ops *ops, unsigned int *tramp_size)
@@ -365,7 +365,12 @@ create_trampoline(struct ftrace_ops *ops
goto fail;
ip = trampoline + size;
- memcpy(ip, retq, RET_SIZE);
+
+ /* The trampoline ends with ret(q) */
+ if (cpu_feature_enabled(X86_FEATURE_RETHUNK))
+ memcpy(ip, text_gen_insn(JMP32_INSN_OPCODE, ip, &__x86_return_thunk), JMP32_INSN_SIZE);
+ else
+ memcpy(ip, retq, sizeof(retq));
/* No need to test direct calls on created trampolines */
if (ops->flags & FTRACE_OPS_FL_SAVE_REGS) {
next prev parent reply other threads:[~2022-08-19 15:43 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-08-19 15:40 [PATCH 5.15 00/14] 5.15.62-rc1 review Greg Kroah-Hartman
2022-08-19 15:40 ` [PATCH 5.15 01/14] io_uring: use original request task for inflight tracking Greg Kroah-Hartman
2022-08-19 15:40 ` [PATCH 5.15 02/14] tee: add overflow check in register_shm_helper() Greg Kroah-Hartman
2022-08-19 15:40 ` [PATCH 5.15 03/14] net_sched: cls_route: disallow handle of 0 Greg Kroah-Hartman
2022-08-19 15:40 ` [PATCH 5.15 04/14] ksmbd: prevent out of bound read for SMB2_WRITE Greg Kroah-Hartman
2022-08-19 15:40 ` [PATCH 5.15 05/14] ksmbd: fix heap-based overflow in set_ntacl_dacl() Greg Kroah-Hartman
2022-08-19 15:40 ` [PATCH 5.15 06/14] Revert "x86/ftrace: Use alternative RET encoding" Greg Kroah-Hartman
2022-08-19 15:40 ` [PATCH 5.15 07/14] x86/ibt,ftrace: Make function-graph play nice Greg Kroah-Hartman
2022-08-19 15:40 ` Greg Kroah-Hartman [this message]
2022-08-19 15:40 ` [PATCH 5.15 09/14] btrfs: only write the sectors in the vertical stripe which has data stripes Greg Kroah-Hartman
2022-08-19 15:40 ` [PATCH 5.15 10/14] btrfs: raid56: dont trust any cached sector in __raid56_parity_recover() Greg Kroah-Hartman
2022-08-19 15:40 ` [PATCH 5.15 11/14] kexec_file: drop weak attribute from functions Greg Kroah-Hartman
2022-08-19 15:40 ` [PATCH 5.15 12/14] kexec: clean up arch_kexec_kernel_verify_sig Greg Kroah-Hartman
2022-08-19 15:40 ` [PATCH 5.15 13/14] kexec, KEYS: make the code in bzImage64_verify_sig generic Greg Kroah-Hartman
2022-08-19 15:40 ` [PATCH 5.15 14/14] arm64: kexec_file: use more system keyrings to verify kernel image signature Greg Kroah-Hartman
2022-08-20 0:42 ` [PATCH 5.15 00/14] 5.15.62-rc1 review Shuah Khan
2022-08-20 8:27 ` Naresh Kamboju
2022-08-20 18:17 ` Greg Kroah-Hartman
2022-08-20 10:05 ` Bagas Sanjaya
2022-08-20 10:42 ` Sudip Mukherjee (Codethink)
2022-08-20 22:23 ` Ron Economos
2022-08-21 0:56 ` Guenter Roeck
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