From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: linux-kernel@vger.kernel.org
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
stable@vger.kernel.org,
"Russell King (Oracle)" <rmk+kernel@armlinux.org.uk>,
Catalin Marinas <catalin.marinas@arm.com>,
James Morse <james.morse@arm.com>
Subject: [PATCH 4.14 18/27] arm64: entry: Add non-kpti __bp_harden_el1_vectors for mitigations
Date: Fri, 1 Apr 2022 08:36:28 +0200 [thread overview]
Message-ID: <20220401063624.749044293@linuxfoundation.org> (raw)
In-Reply-To: <20220401063624.232282121@linuxfoundation.org>
From: James Morse <james.morse@arm.com>
commit aff65393fa1401e034656e349abd655cfe272de0 upstream.
kpti is an optional feature, for systems not using kpti a set of
vectors for the spectre-bhb mitigations is needed.
Add another set of vectors, __bp_harden_el1_vectors, that will be
used if a mitigation is needed and kpti is not in use.
The EL1 ventries are repeated verbatim as there is no additional
work needed for entry from EL1.
Reviewed-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: James Morse <james.morse@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
arch/arm64/kernel/entry.S | 34 +++++++++++++++++++++++++++++++++-
1 file changed, 33 insertions(+), 1 deletion(-)
--- a/arch/arm64/kernel/entry.S
+++ b/arch/arm64/kernel/entry.S
@@ -1025,10 +1025,11 @@ alternative_else_nop_endif
.macro tramp_ventry, vector_start, regsize, kpti
.align 7
1:
- .if \kpti == 1
.if \regsize == 64
msr tpidrro_el0, x30 // Restored in kernel_ventry
.endif
+
+ .if \kpti == 1
/*
* Defend against branch aliasing attacks by pushing a dummy
* entry onto the return stack and using a RET instruction to
@@ -1112,6 +1113,37 @@ __entry_tramp_data_start:
#endif /* CONFIG_UNMAP_KERNEL_AT_EL0 */
/*
+ * Exception vectors for spectre mitigations on entry from EL1 when
+ * kpti is not in use.
+ */
+ .macro generate_el1_vector
+.Lvector_start\@:
+ kernel_ventry 1, sync_invalid // Synchronous EL1t
+ kernel_ventry 1, irq_invalid // IRQ EL1t
+ kernel_ventry 1, fiq_invalid // FIQ EL1t
+ kernel_ventry 1, error_invalid // Error EL1t
+
+ kernel_ventry 1, sync // Synchronous EL1h
+ kernel_ventry 1, irq // IRQ EL1h
+ kernel_ventry 1, fiq_invalid // FIQ EL1h
+ kernel_ventry 1, error_invalid // Error EL1h
+
+ .rept 4
+ tramp_ventry .Lvector_start\@, 64, kpti=0
+ .endr
+ .rept 4
+ tramp_ventry .Lvector_start\@, 32, kpti=0
+ .endr
+ .endm
+
+ .pushsection ".entry.text", "ax"
+ .align 11
+ENTRY(__bp_harden_el1_vectors)
+ generate_el1_vector
+END(__bp_harden_el1_vectors)
+ .popsection
+
+/*
* Special system call wrappers.
*/
ENTRY(sys_rt_sigreturn_wrapper)
next prev parent reply other threads:[~2022-04-01 6:37 UTC|newest]
Thread overview: 30+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-04-01 6:36 [PATCH 4.14 00/27] 4.14.275-rc1 review Greg Kroah-Hartman
2022-04-01 6:36 ` [PATCH 4.14 01/27] arm64: arch_timer: Add workaround for ARM erratum 1188873 Greg Kroah-Hartman
2022-04-01 6:36 ` [PATCH 4.14 02/27] arm64: arch_timer: avoid unused function warning Greg Kroah-Hartman
2022-04-01 6:36 ` [PATCH 4.14 03/27] arm64: Add silicon-errata.txt entry for ARM erratum 1188873 Greg Kroah-Hartman
2022-04-01 6:36 ` [PATCH 4.14 04/27] arm64: Make ARM64_ERRATUM_1188873 depend on COMPAT Greg Kroah-Hartman
2022-04-01 6:36 ` [PATCH 4.14 05/27] arm64: Add part number for Neoverse N1 Greg Kroah-Hartman
2022-04-01 6:36 ` [PATCH 4.14 06/27] arm64: Add part number for Arm Cortex-A77 Greg Kroah-Hartman
2022-04-01 6:36 ` [PATCH 4.14 07/27] arm64: Add Neoverse-N2, Cortex-A710 CPU part definition Greg Kroah-Hartman
2022-04-01 6:36 ` [PATCH 4.14 08/27] arm64: Add Cortex-X2 " Greg Kroah-Hartman
2022-04-01 6:36 ` [PATCH 4.14 09/27] arm64: entry.S: Add ventry overflow sanity checks Greg Kroah-Hartman
2022-04-01 6:36 ` [PATCH 4.14 10/27] arm64: entry: Make the trampoline cleanup optional Greg Kroah-Hartman
2022-04-01 6:36 ` [PATCH 4.14 11/27] arm64: entry: Free up another register on kptis tramp_exit path Greg Kroah-Hartman
2022-04-01 6:36 ` [PATCH 4.14 12/27] arm64: entry: Move the trampoline data page before the text page Greg Kroah-Hartman
2022-04-01 6:36 ` [PATCH 4.14 13/27] arm64: entry: Allow tramp_alias to access symbols after the 4K boundary Greg Kroah-Hartman
2022-04-01 6:36 ` [PATCH 4.14 14/27] arm64: entry: Dont assume tramp_vectors is the start of the vectors Greg Kroah-Hartman
2022-04-01 6:36 ` [PATCH 4.14 15/27] arm64: entry: Move trampoline macros out of ifdefd section Greg Kroah-Hartman
2022-04-01 6:36 ` [PATCH 4.14 16/27] arm64: entry: Make the kpti trampolines kpti sequence optional Greg Kroah-Hartman
2022-04-01 6:36 ` [PATCH 4.14 17/27] arm64: entry: Allow the trampoline text to occupy multiple pages Greg Kroah-Hartman
2022-04-01 6:36 ` Greg Kroah-Hartman [this message]
2022-04-01 6:36 ` [PATCH 4.14 19/27] arm64: entry: Add vectors that have the bhb mitigation sequences Greg Kroah-Hartman
2022-04-01 6:36 ` [PATCH 4.14 20/27] arm64: entry: Add macro for reading symbol addresses from the trampoline Greg Kroah-Hartman
2022-04-01 6:36 ` [PATCH 4.14 21/27] arm64: Add percpu vectors for EL1 Greg Kroah-Hartman
2022-04-01 6:36 ` [PATCH 4.14 22/27] arm64: proton-pack: Report Spectre-BHB vulnerabilities as part of Spectre-v2 Greg Kroah-Hartman
2022-04-01 6:36 ` [PATCH 4.14 23/27] KVM: arm64: Add templates for BHB mitigation sequences Greg Kroah-Hartman
2022-04-01 6:36 ` [PATCH 4.14 24/27] arm64: Mitigate spectre style branch history side channels Greg Kroah-Hartman
2022-04-01 6:36 ` [PATCH 4.14 25/27] KVM: arm64: Allow SMCCC_ARCH_WORKAROUND_3 to be discovered and migrated Greg Kroah-Hartman
2022-04-01 6:36 ` [PATCH 4.14 26/27] arm64: add ID_AA64ISAR2_EL1 sys register Greg Kroah-Hartman
2022-04-01 6:36 ` [PATCH 4.14 27/27] arm64: Use the clearbhb instruction in mitigations Greg Kroah-Hartman
2022-04-01 10:43 ` [PATCH 4.14 00/27] 4.14.275-rc1 review Guenter Roeck
2022-04-01 18:26 ` Naresh Kamboju
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