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arm64: smccc: Save lr before calling __arm_smccc_sve_check()

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Commit cfa7ff959a ("arm64: smccc: Support SMCCC v1.3 SVE register
saving hint") added a call to __arm_smccc_sve_check() which clobbers the
lr (register x30), causing __arm_smccc_hvc() to return to itself and
crash. Save lr on the stack before calling __arm_smccc_sve_check(). Save
the frame pointer (x29) to complete the frame record, and adjust the
offsets used to access stack parameters.

Acked-by: Ard Biesheuvel <ardb@kernel.org>
Acked-by: Mark Brown <broonie@kernel.org>
Fixes: cfa7ff959a ("arm64: smccc: Support SMCCC v1.3 SVE register saving hint")
Signed-off-by: Jean-Philippe Brucker <jean-philippe@linaro.org>
Link: https://lore.kernel.org/r/20210721071834.69130-1-jean-philippe@linaro.org
Signed-off-by: Will Deacon <will@kernel.org>
This commit is contained in:
Jean-Philippe Brucker 2021-07-21 09:18:35 +02:00 committed by Will Deacon
parent e6f85cbeb2
commit a7c3acca53
1 changed files with 6 additions and 3 deletions
repo.diff.show_diff_stats Download patch file Download diff file Expand all files Collapse all files

9
arch/arm64/kernel/smccc-call.S
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@ -32,20 +32,23 @@ SYM_FUNC_END(__arm_smccc_sve_check)
EXPORT_SYMBOL(__arm_smccc_sve_check)
.macro SMCCC instr
stp x29, x30, [sp, #-16]!
mov x29, sp
alternative_if ARM64_SVE
bl __arm_smccc_sve_check
alternative_else_nop_endif
\instr #0
ldr x4, [sp]
ldr x4, [sp, #16]
stp x0, x1, [x4, #ARM_SMCCC_RES_X0_OFFS]
stp x2, x3, [x4, #ARM_SMCCC_RES_X2_OFFS]
ldr x4, [sp, #8]
ldr x4, [sp, #24]
cbz x4, 1f /* no quirk structure */
ldr x9, [x4, #ARM_SMCCC_QUIRK_ID_OFFS]
cmp x9, #ARM_SMCCC_QUIRK_QCOM_A6
b.ne 1f
str x6, [x4, ARM_SMCCC_QUIRK_STATE_OFFS]
1: ret
1: ldp x29, x30, [sp], #16
ret
.endm
/*