From: James Morse <james.morse@arm.com>
To: stable@vger.kernel.org
Cc: catalin.marinas@arm.com, linux-arm-kernel@lists.infradead.org,
james.morse@arm.com
Subject: [stable:PATCH v5.4.184 12/22] arm64: entry: Make the kpti trampoline's kpti sequence optional
Date: Tue, 15 Mar 2022 18:24:05 +0000 [thread overview]
Message-ID: <20220315182415.3900464-13-james.morse@arm.com> (raw)
In-Reply-To: <20220315182415.3900464-1-james.morse@arm.com>
commit c47e4d04ba0f1ea17353d85d45f611277507e07a upstream.
Spectre-BHB needs to add sequences to the vectors. Having one global
set of vectors is a problem for big/little systems where the sequence
is costly on cpus that are not vulnerable.
Making the vectors per-cpu in the style of KVM's bh_harden_hyp_vecs
requires the vectors to be generated by macros.
Make the kpti re-mapping of the kernel optional, so the macros can be
used without kpti.
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>
---
arch/arm64/kernel/entry.S | 18 ++++++++++++------
1 file changed, 12 insertions(+), 6 deletions(-)
diff --git a/arch/arm64/kernel/entry.S b/arch/arm64/kernel/entry.S
index a2ec7ef24402..bb456f596c43 100644
--- a/arch/arm64/kernel/entry.S
+++ b/arch/arm64/kernel/entry.S
@@ -1063,9 +1063,10 @@ alternative_else_nop_endif
sub \dst, \dst, PAGE_SIZE
.endm
- .macro tramp_ventry, vector_start, regsize
+ .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
@@ -1088,9 +1089,14 @@ alternative_insn isb, nop, ARM64_WORKAROUND_QCOM_FALKOR_E1003
alternative_if_not ARM64_WORKAROUND_CAVIUM_TX2_219_PRFM
prfm plil1strm, [x30, #(1b - \vector_start)]
alternative_else_nop_endif
+
msr vbar_el1, x30
+ isb
+ .else
+ ldr x30, =vectors
+ .endif // \kpti == 1
+
add x30, x30, #(1b - \vector_start + 4)
- isb
ret
.org 1b + 128 // Did we overflow the ventry slot?
.endm
@@ -1108,15 +1114,15 @@ alternative_else_nop_endif
sb
.endm
- .macro generate_tramp_vector
+ .macro generate_tramp_vector, kpti
.Lvector_start\@:
.space 0x400
.rept 4
- tramp_ventry .Lvector_start\@, 64
+ tramp_ventry .Lvector_start\@, 64, \kpti
.endr
.rept 4
- tramp_ventry .Lvector_start\@, 32
+ tramp_ventry .Lvector_start\@, 32, \kpti
.endr
.endm
@@ -1127,7 +1133,7 @@ alternative_else_nop_endif
.pushsection ".entry.tramp.text", "ax"
.align 11
ENTRY(tramp_vectors)
- generate_tramp_vector
+ generate_tramp_vector kpti=1
END(tramp_vectors)
ENTRY(tramp_exit_native)
--
2.30.2
next prev parent reply other threads:[~2022-03-15 18:24 UTC|newest]
Thread overview: 28+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-03-15 18:23 [stable:PATCH v5.4.184 00/22] arm64: Mitigate spectre style branch history side channels James Morse
2022-03-15 18:23 ` [stable:PATCH v5.4.184 01/22] arm64: Add part number for Arm Cortex-A77 James Morse
2022-03-15 18:23 ` [stable:PATCH v5.4.184 02/22] arm64: Add Neoverse-N2, Cortex-A710 CPU part definition James Morse
2022-03-15 18:23 ` [stable:PATCH v5.4.184 03/22] arm64: add ID_AA64ISAR2_EL1 sys register James Morse
2022-03-15 18:23 ` [stable:PATCH v5.4.184 04/22] arm64: Add Cortex-X2 CPU part definition James Morse
2022-03-15 18:23 ` [stable:PATCH v5.4.184 05/22] arm64: entry.S: Add ventry overflow sanity checks James Morse
2022-03-15 18:23 ` [stable:PATCH v5.4.184 06/22] arm64: entry: Make the trampoline cleanup optional James Morse
2022-03-15 18:24 ` [stable:PATCH v5.4.184 07/22] arm64: entry: Free up another register on kpti's tramp_exit path James Morse
2022-03-15 18:24 ` [stable:PATCH v5.4.184 08/22] arm64: entry: Move the trampoline data page before the text page James Morse
2022-03-15 18:24 ` [stable:PATCH v5.4.184 09/22] arm64: entry: Allow tramp_alias to access symbols after the 4K boundary James Morse
2022-03-15 18:24 ` [stable:PATCH v5.4.184 10/22] arm64: entry: Don't assume tramp_vectors is the start of the vectors James Morse
2022-03-15 18:24 ` [stable:PATCH v5.4.184 11/22] arm64: entry: Move trampoline macros out of ifdef'd section James Morse
2022-03-15 18:24 ` James Morse [this message]
2022-03-15 18:24 ` [stable:PATCH v5.4.184 13/22] arm64: entry: Allow the trampoline text to occupy multiple pages James Morse
2022-03-15 18:24 ` [stable:PATCH v5.4.184 14/22] arm64: entry: Add non-kpti __bp_harden_el1_vectors for mitigations James Morse
2022-03-15 18:24 ` [stable:PATCH v5.4.184 15/22] arm64: entry: Add vectors that have the bhb mitigation sequences James Morse
2022-03-15 18:24 ` [stable:PATCH v5.4.184 16/22] arm64: entry: Add macro for reading symbol addresses from the trampoline James Morse
2022-03-15 18:24 ` [stable:PATCH v5.4.184 17/22] arm64: Add percpu vectors for EL1 James Morse
2022-03-15 18:24 ` [stable:PATCH v5.4.184 18/22] arm64: proton-pack: Report Spectre-BHB vulnerabilities as part of Spectre-v2 James Morse
2022-03-15 18:24 ` [stable:PATCH v5.4.184 19/22] KVM: arm64: Add templates for BHB mitigation sequences James Morse
2022-03-15 18:24 ` [stable:PATCH v5.4.184 20/22] arm64: Mitigate spectre style branch history side channels James Morse
2022-03-15 18:24 ` [stable:PATCH v5.4.184 21/22] KVM: arm64: Allow SMCCC_ARCH_WORKAROUND_3 to be discovered and migrated James Morse
2022-03-15 18:24 ` [stable:PATCH v5.4.184 22/22] arm64: Use the clearbhb instruction in mitigations James Morse
2022-03-16 15:41 ` [stable:PATCH v5.4.184 00/22] arm64: Mitigate spectre style branch history side channels Sasha Levin
2022-03-16 17:38 ` James Morse
2022-03-16 18:43 ` Sasha Levin
2022-03-17 10:00 ` Greg KH
2022-03-18 12:15 ` James Morse
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