From: Thadeu Lima de Souza Cascardo <cascardo@canonical.com>
To: stable@vger.kernel.org
Cc: x86@kernel.org, kvm@vger.kernel.org, bp@alien8.de,
pbonzini@redhat.com, peterz@infradead.org, jpoimboe@kernel.org
Subject: [PATCH 5.4 18/37] x86/speculation: Change FILL_RETURN_BUFFER to work with objtool
Date: Mon, 3 Oct 2022 10:10:19 -0300 [thread overview]
Message-ID: <20221003131038.12645-19-cascardo@canonical.com> (raw)
In-Reply-To: <20221003131038.12645-1-cascardo@canonical.com>
From: Peter Zijlstra <peterz@infradead.org>
commit 089dd8e53126ebaf506e2dc0bf89d652c36bfc12 upstream.
Change FILL_RETURN_BUFFER so that objtool groks it and can generate
correct ORC unwind information.
- Since ORC is alternative invariant; that is, all alternatives
should have the same ORC entries, the __FILL_RETURN_BUFFER body
can not be part of an alternative.
Therefore, move it out of the alternative and keep the alternative
as a sort of jump_label around it.
- Use the ANNOTATE_INTRA_FUNCTION_CALL annotation to white-list
these 'funny' call instructions to nowhere.
- Use UNWIND_HINT_EMPTY to 'fill' the speculation traps, otherwise
objtool will consider them unreachable.
- Move the RSP adjustment into the loop, such that the loop has a
deterministic stack layout.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Alexandre Chartre <alexandre.chartre@oracle.com>
Acked-by: Josh Poimboeuf <jpoimboe@redhat.com>
Link: https://lkml.kernel.org/r/20200428191700.032079304@infradead.org
[cascardo: fixup because of backport of ba6e31af2be96c4d0536f2152ed6f7b6c11bca47 ("x86/speculation: Add LFENCE to RSB fill sequence")]
[cascardo: no intra-function call validation support]
[cascardo: avoid UNWIND_HINT_EMPTY because of svm]
Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com>
---
arch/x86/include/asm/nospec-branch.h | 10 +++++-----
1 file changed, 5 insertions(+), 5 deletions(-)
diff --git a/arch/x86/include/asm/nospec-branch.h b/arch/x86/include/asm/nospec-branch.h
index 0b1630c2c46b..460360cfab5a 100644
--- a/arch/x86/include/asm/nospec-branch.h
+++ b/arch/x86/include/asm/nospec-branch.h
@@ -4,11 +4,13 @@
#define _ASM_X86_NOSPEC_BRANCH_H_
#include <linux/static_key.h>
+#include <linux/frame.h>
#include <asm/alternative.h>
#include <asm/alternative-asm.h>
#include <asm/cpufeatures.h>
#include <asm/msr-index.h>
+#include <asm/unwind_hints.h>
/*
* This should be used immediately before a retpoline alternative. It tells
@@ -60,9 +62,9 @@
lfence; \
jmp 775b; \
774: \
+ add $(BITS_PER_LONG/8) * 2, sp; \
dec reg; \
jnz 771b; \
- add $(BITS_PER_LONG/8) * nr, sp; \
/* barrier for jnz misprediction */ \
lfence;
#else
@@ -154,10 +156,8 @@
*/
.macro FILL_RETURN_BUFFER reg:req nr:req ftr:req
#ifdef CONFIG_RETPOLINE
- ANNOTATE_NOSPEC_ALTERNATIVE
- ALTERNATIVE "jmp .Lskip_rsb_\@", \
- __stringify(__FILL_RETURN_BUFFER(\reg,\nr,%_ASM_SP)) \
- \ftr
+ ALTERNATIVE "jmp .Lskip_rsb_\@", "", \ftr
+ __FILL_RETURN_BUFFER(\reg,\nr,%_ASM_SP)
.Lskip_rsb_\@:
#endif
.endm
--
2.34.1
next prev parent reply other threads:[~2022-10-03 13:12 UTC|newest]
Thread overview: 39+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-10-03 13:10 [PATCH 5.4 00/37] IBRS support // Retbleed mitigations Thadeu Lima de Souza Cascardo
2022-10-03 13:10 ` [PATCH 5.4 01/37] Revert "x86/speculation: Add RSB VM Exit protections" Thadeu Lima de Souza Cascardo
2022-10-03 13:10 ` [PATCH 5.4 02/37] Revert "x86/cpu: Add a steppings field to struct x86_cpu_id" Thadeu Lima de Souza Cascardo
2022-10-03 13:10 ` [PATCH 5.4 03/37] x86/devicetable: Move x86 specific macro out of generic code Thadeu Lima de Souza Cascardo
2022-10-03 13:10 ` [PATCH 5.4 04/37] x86/cpu: Add consistent CPU match macros Thadeu Lima de Souza Cascardo
2022-10-03 13:10 ` [PATCH 5.4 05/37] x86/cpu: Add a steppings field to struct x86_cpu_id Thadeu Lima de Souza Cascardo
2022-10-03 13:10 ` [PATCH 5.4 06/37] x86/kvm/vmx: Make noinstr clean Thadeu Lima de Souza Cascardo
2022-10-03 13:10 ` [PATCH 5.4 07/37] x86/cpufeatures: Move RETPOLINE flags to word 11 Thadeu Lima de Souza Cascardo
2022-10-03 13:10 ` [PATCH 5.4 08/37] x86/bugs: Report AMD retbleed vulnerability Thadeu Lima de Souza Cascardo
2022-10-03 13:10 ` [PATCH 5.4 09/37] x86/bugs: Add AMD retbleed= boot parameter Thadeu Lima de Souza Cascardo
2022-10-03 13:10 ` [PATCH 5.4 10/37] x86/bugs: Keep a per-CPU IA32_SPEC_CTRL value Thadeu Lima de Souza Cascardo
2022-10-03 13:10 ` [PATCH 5.4 11/37] x86/entry: Remove skip_r11rcx Thadeu Lima de Souza Cascardo
2022-10-03 13:10 ` [PATCH 5.4 12/37] x86/entry: Add kernel IBRS implementation Thadeu Lima de Souza Cascardo
2022-10-03 13:10 ` [PATCH 5.4 13/37] x86/bugs: Optimize SPEC_CTRL MSR writes Thadeu Lima de Souza Cascardo
2022-10-03 13:10 ` [PATCH 5.4 14/37] x86/speculation: Add spectre_v2=ibrs option to support Kernel IBRS Thadeu Lima de Souza Cascardo
2022-10-03 13:10 ` [PATCH 5.4 15/37] x86/bugs: Split spectre_v2_select_mitigation() and spectre_v2_user_select_mitigation() Thadeu Lima de Souza Cascardo
2022-10-03 13:10 ` [PATCH 5.4 16/37] x86/bugs: Report Intel retbleed vulnerability Thadeu Lima de Souza Cascardo
2022-10-03 13:10 ` [PATCH 5.4 17/37] intel_idle: Disable IBRS during long idle Thadeu Lima de Souza Cascardo
2022-10-03 13:10 ` Thadeu Lima de Souza Cascardo [this message]
2022-10-03 13:10 ` [PATCH 5.4 19/37] x86/speculation: Fix RSB filling with CONFIG_RETPOLINE=n Thadeu Lima de Souza Cascardo
2022-10-03 13:10 ` [PATCH 5.4 20/37] x86/speculation: Fix firmware entry SPEC_CTRL handling Thadeu Lima de Souza Cascardo
2022-10-03 13:10 ` [PATCH 5.4 21/37] x86/speculation: Fix SPEC_CTRL write on SMT state change Thadeu Lima de Souza Cascardo
2022-10-03 13:10 ` [PATCH 5.4 22/37] x86/speculation: Use cached host SPEC_CTRL value for guest entry/exit Thadeu Lima de Souza Cascardo
2022-10-03 13:10 ` [PATCH 5.4 23/37] x86/speculation: Remove x86_spec_ctrl_mask Thadeu Lima de Souza Cascardo
2022-10-03 13:10 ` [PATCH 5.4 24/37] KVM/VMX: Use TEST %REG,%REG instead of CMP $0,%REG in vmenter.S Thadeu Lima de Souza Cascardo
2022-10-03 13:10 ` [PATCH 5.4 25/37] KVM/nVMX: Use __vmx_vcpu_run in nested_vmx_check_vmentry_hw Thadeu Lima de Souza Cascardo
2022-10-03 13:10 ` [PATCH 5.4 26/37] KVM: VMX: Flatten __vmx_vcpu_run() Thadeu Lima de Souza Cascardo
2022-10-03 13:10 ` [PATCH 5.4 27/37] KVM: VMX: Convert launched argument to flags Thadeu Lima de Souza Cascardo
2022-10-03 13:10 ` [PATCH 5.4 28/37] KVM: VMX: Prevent guest RSB poisoning attacks with eIBRS Thadeu Lima de Souza Cascardo
2022-10-03 13:10 ` [PATCH 5.4 29/37] KVM: VMX: Fix IBRS handling after vmexit Thadeu Lima de Souza Cascardo
2022-10-03 13:10 ` [PATCH 5.4 30/37] x86/speculation: Fill RSB on vmexit for IBRS Thadeu Lima de Souza Cascardo
2022-10-03 13:10 ` [PATCH 5.4 31/37] x86/common: Stamp out the stepping madness Thadeu Lima de Souza Cascardo
2022-10-03 13:10 ` [PATCH 5.4 32/37] x86/cpu/amd: Enumerate BTC_NO Thadeu Lima de Souza Cascardo
2022-10-03 13:10 ` [PATCH 5.4 33/37] x86/bugs: Add Cannon lake to RETBleed affected CPU list Thadeu Lima de Souza Cascardo
2022-10-03 13:10 ` [PATCH 5.4 34/37] x86/speculation: Disable RRSBA behavior Thadeu Lima de Souza Cascardo
2022-10-03 13:10 ` [PATCH 5.4 35/37] x86/speculation: Use DECLARE_PER_CPU for x86_spec_ctrl_current Thadeu Lima de Souza Cascardo
2022-10-03 13:10 ` [PATCH 5.4 36/37] x86/bugs: Warn when "ibrs" mitigation is selected on Enhanced IBRS parts Thadeu Lima de Souza Cascardo
2022-10-03 13:10 ` [PATCH 5.4 37/37] x86/speculation: Add RSB VM Exit protections Thadeu Lima de Souza Cascardo
2022-10-05 10:34 ` [PATCH 5.4 00/37] IBRS support // Retbleed mitigations Greg KH
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