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From: Chen Zhongjin <chenzhongjin@huawei.com>
To: <linux-kernel@vger.kernel.org>,
	<linux-arm-kernel@lists.infradead.org>,
	<linux-arch@vger.kernel.org>
Cc: <jthierry@redhat.com>, <catalin.marinas@arm.com>,
	<will@kernel.org>, <masahiroy@kernel.org>, <jpoimboe@redhat.com>,
	<peterz@infradead.org>, <ycote@redhat.com>,
	<herbert@gondor.apana.org.au>, <mark.rutland@arm.com>,
	<davem@davemloft.net>, <ardb@kernel.org>, <maz@kernel.org>,
	<tglx@linutronix.de>, <luc.vanoostenryck@gmail.com>,
	<chenzhongjin@huawei.com>
Subject: [RFC PATCH v4 36/37] arm64: entry: Align stack size for alternative
Date: Fri, 29 Apr 2022 17:43:54 +0800	[thread overview]
Message-ID: <20220429094355.122389-37-chenzhongjin@huawei.com> (raw)
In-Reply-To: <20220429094355.122389-1-chenzhongjin@huawei.com>

In kernel_exit there is a alternative branch for KPTI which causes
stack size conflict for two instruction boundaries.

To fix that, make both branch move the sp and then revert it in
tramp_exit branch.

Signed-off-by: Chen Zhongjin <chenzhongjin@huawei.com>
---
 arch/arm64/kernel/entry.S | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/arch/arm64/kernel/entry.S b/arch/arm64/kernel/entry.S
index c7ab5143949f..fa3c5a2cd2c3 100644
--- a/arch/arm64/kernel/entry.S
+++ b/arch/arm64/kernel/entry.S
@@ -429,7 +429,11 @@ alternative_if_not ARM64_UNMAP_KERNEL_AT_EL0
 	ldr	lr, [sp, #S_LR]
 	add	sp, sp, #PT_REGS_SIZE		// restore sp
 	eret
-alternative_else_nop_endif
+alternative_else
+	nop
+	add sp, sp, #PT_REGS_SIZE       // restore sp
+	nop
+alternative_endif
 #ifdef CONFIG_UNMAP_KERNEL_AT_EL0
 	bne	4f
 	msr	far_el1, x29
@@ -726,6 +730,7 @@ alternative_else_nop_endif
 	.endm
 
 	.macro tramp_exit, regsize = 64
+	sub sp, sp, #PT_REGS_SIZE       // revert sp
 	tramp_data_read_var	x30, this_cpu_vector
 	get_this_cpu_offset x29
 	ldr	x30, [x30, x29]
-- 
2.17.1


  parent reply	other threads:[~2022-04-29  9:46 UTC|newest]

Thread overview: 48+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-04-29  9:43 [RFC PATCH v4 00/37] objtool: add base support for arm64 Chen Zhongjin
2022-04-29  9:43 ` [RFC PATCH v4 01/37] tools: Add some generic functions and headers Chen Zhongjin
2022-04-29  9:43 ` [RFC PATCH v4 02/37] tools: arm64: Make aarch64 instruction decoder available to tools Chen Zhongjin
2022-04-29  9:43 ` [RFC PATCH v4 03/37] tools: bug: Remove duplicate definition Chen Zhongjin
2022-04-29  9:43 ` [RFC PATCH v4 04/37] objtool: arm64: Add base definition for arm64 backend Chen Zhongjin
2022-04-29  9:43 ` [RFC PATCH v4 05/37] objtool: arm64: Decode add/sub instructions Chen Zhongjin
2022-04-29  9:43 ` [RFC PATCH v4 06/37] objtool: arm64: Decode jump and call related instructions Chen Zhongjin
2022-04-29  9:43 ` [RFC PATCH v4 07/37] objtool: arm64: Decode other system instructions Chen Zhongjin
2022-04-29  9:43 ` [RFC PATCH v4 08/37] objtool: arm64: Decode load/store instructions Chen Zhongjin
2022-04-29  9:43 ` [RFC PATCH v4 09/37] objtool: arm64: Decode LDR instructions Chen Zhongjin
2022-04-29  9:43 ` [RFC PATCH v4 10/37] objtool: arm64: Accept non-instruction data in code sections Chen Zhongjin
2022-04-29  9:43 ` [RFC PATCH v4 11/37] objtool: arm64: Handle supported relocations in alternatives Chen Zhongjin
2022-04-29  9:43 ` [RFC PATCH v4 12/37] objtool: arm64: Ignore replacement section for alternative callback Chen Zhongjin
2022-04-29  9:43 ` [RFC PATCH v4 13/37] objtool: arm64: Enable stack validation for arm64 Chen Zhongjin
2022-04-29  9:43 ` [RFC PATCH v4 14/37] objtool: check: Support data in text section Chen Zhongjin
2022-04-29  9:43 ` [RFC PATCH v4 15/37] objtool: arm64: Add unwind_hint support Chen Zhongjin
2022-04-29  9:43 ` [RFC PATCH v4 16/37] arm64: Add annotate_reachable() for objtools Chen Zhongjin
2022-04-29  9:43 ` [RFC PATCH v4 17/37] arm64: bug: Add reachable annotation to warning macros Chen Zhongjin
2022-04-29  9:43 ` [RFC PATCH v4 18/37] arm64: kgdb: Mark code following kgdb brk as reachable Chen Zhongjin
2022-04-29  9:43 ` [RFC PATCH v4 19/37] arm64: irq-gic: Replace unreachable() with -EINVAL Chen Zhongjin
2022-04-29  9:43 ` [RFC PATCH v4 20/37] arm64: Set intra-function call annotations Chen Zhongjin
2022-04-29  9:43 ` [RFC PATCH v4 21/37] arm64: kernel: Skip validation of proton-pack.c.c and hibernate.c Chen Zhongjin
2022-04-29  9:43 ` [RFC PATCH v4 22/37] arm64: kernel: Skip validation of kuser32.o Chen Zhongjin
2022-04-29 11:05   ` Peter Zijlstra
2022-05-05  3:36     ` Chen Zhongjin
2022-05-05  9:24       ` Peter Zijlstra
2022-05-05 10:56         ` Mark Rutland
2022-05-06  2:18           ` Chen Zhongjin
2022-05-06 10:06             ` Mark Rutland
2022-05-07  6:35               ` Chen Zhongjin
2022-05-06 17:31           ` Josh Poimboeuf
2022-04-29  9:43 ` [RFC PATCH v4 23/37] arm64: kernel: Skip validation of sigreturn32.o Chen Zhongjin
2022-04-29  9:43 ` [RFC PATCH v4 24/37] arm64: ftrace: Skip validation of entry-ftrace.o Chen Zhongjin
2022-04-29  9:43 ` [RFC PATCH v4 25/37] arm64: bpf: Skip validation of ___bpf_prog_run Chen Zhongjin
2022-04-29 11:13   ` Peter Zijlstra
2022-04-29 20:09     ` Josh Poimboeuf
2022-04-29  9:43 ` [RFC PATCH v4 26/37] arm64: crypto: Remove unnecessary stackframe Chen Zhongjin
2022-04-29  9:43 ` [RFC PATCH v4 27/37] arm64: sleep: Properly set frame pointer before call Chen Zhongjin
2022-04-29  9:43 ` [RFC PATCH v4 28/37] arm64: Change symbol annotations Chen Zhongjin
2022-04-29  9:43 ` [RFC PATCH v4 29/37] arm64: efi-header: Mark efi header as data Chen Zhongjin
2022-04-29  9:43 ` [RFC PATCH v4 30/37] arm64: head: Mark constants " Chen Zhongjin
2022-04-29  9:43 ` [RFC PATCH v4 31/37] arm64: proc: Mark constant " Chen Zhongjin
2022-04-29  9:43 ` [RFC PATCH v4 32/37] arm64: crypto: Mark data in code sections Chen Zhongjin
2022-04-29  9:43 ` [RFC PATCH v4 33/37] arm64: Annotate ASM symbols with unknown stack state Chen Zhongjin
2022-04-29  9:43 ` [RFC PATCH v4 34/37] arm64: entry: Annotate valid stack in kernel entry Chen Zhongjin
2022-04-29  9:43 ` [RFC PATCH v4 35/37] arm64: entry: Annotate code switching to tasks Chen Zhongjin
2022-04-29  9:43 ` Chen Zhongjin [this message]
2022-04-29  9:43 ` [RFC PATCH v4 37/37] arm64: kvm: Annotate stack state for guest enter/exit code Chen Zhongjin

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