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 16/27] arm64: entry: Make the kpti trampolines kpti sequence optional
Date: Fri, 1 Apr 2022 08:36:26 +0200 [thread overview]
Message-ID: <20220401063624.693165633@linuxfoundation.org> (raw)
In-Reply-To: <20220401063624.232282121@linuxfoundation.org>
From: James Morse <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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
arch/arm64/kernel/entry.S | 17 +++++++++++------
1 file changed, 11 insertions(+), 6 deletions(-)
--- a/arch/arm64/kernel/entry.S
+++ b/arch/arm64/kernel/entry.S
@@ -1022,9 +1022,10 @@ 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
@@ -1046,8 +1047,12 @@ alternative_insn isb, nop, ARM64_WORKARO
#endif
prfm plil1strm, [x30, #(1b - \vector_start)]
msr vbar_el1, x30
- add x30, x30, #(1b - \vector_start + 4)
isb
+ .else
+ ldr x30, =vectors
+ .endif // \kpti == 1
+
+ add x30, x30, #(1b - \vector_start + 4)
ret
.org 1b + 128 // Did we overflow the ventry slot?
.endm
@@ -1064,15 +1069,15 @@ alternative_insn isb, nop, ARM64_WORKARO
eret
.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
@@ -1083,7 +1088,7 @@ alternative_insn isb, nop, ARM64_WORKARO
.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)
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 ` Greg Kroah-Hartman [this message]
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 ` [PATCH 4.14 18/27] arm64: entry: Add non-kpti __bp_harden_el1_vectors for mitigations Greg Kroah-Hartman
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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