diff options
| author | Steve Capper <steve.capper@arm.com> | 2018-01-24 09:27:08 +0100 |
|---|---|---|
| committer | Catalin Marinas <catalin.marinas@arm.com> | 2018-01-26 19:23:17 +0100 |
| commit | ec89ab50a03a33a4a648869e868b1964354fb2d1 (patch) | |
| tree | fca3a39f0042db178584d91eef67f046abe3c2ab | |
| parent | arm64: Turn on KPTI only on CPUs that need it (diff) | |
| download | linux-ec89ab50a03a33a4a648869e868b1964354fb2d1.tar.xz linux-ec89ab50a03a33a4a648869e868b1964354fb2d1.zip | |
arm64: Fix TTBR + PAN + 52-bit PA logic in cpu_do_switch_mm
In cpu_do_switch_mm(.) with ARM64_SW_TTBR0_PAN=y we apply phys_to_ttbr
to a value that already has an ASID inserted into the upper bits. For
52-bit PA configurations this then can give us TTBR0_EL1 registers that
cause translation table walks to attempt to access non-zero PA[51:48]
spuriously. Ultimately leading to a Synchronous External Abort on level
1 translation.
This patch re-arranges the logic in cpu_do_switch_mm(.) such that
phys_to_ttbr is called before the ASID is inserted into the TTBR0 value.
Fixes: 6b88a32c7af6 ("arm64: kpti: Fix the interaction between ASID switching and software PAN")
Acked-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Tested-by: Kristina Martsenko <kristina.martsenko@arm.com>
Reviewed-by: Kristina Martsenko <kristina.martsenko@arm.com>
Signed-off-by: Steve Capper <steve.capper@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
| -rw-r--r-- | arch/arm64/mm/proc.S | 6 |
1 files changed, 3 insertions, 3 deletions
diff --git a/arch/arm64/mm/proc.S b/arch/arm64/mm/proc.S index c6a12073ef46..9f177aac6390 100644 --- a/arch/arm64/mm/proc.S +++ b/arch/arm64/mm/proc.S @@ -153,14 +153,14 @@ ENDPROC(cpu_do_resume) ENTRY(cpu_do_switch_mm) mrs x2, ttbr1_el1 mmid x1, x1 // get mm->context.id + phys_to_ttbr x0, x3 #ifdef CONFIG_ARM64_SW_TTBR0_PAN - bfi x0, x1, #48, #16 // set the ASID field in TTBR0 + bfi x3, x1, #48, #16 // set the ASID field in TTBR0 #endif bfi x2, x1, #48, #16 // set the ASID msr ttbr1_el1, x2 // in TTBR1 (since TCR.A1 is set) isb - phys_to_ttbr x0, x2 - msr ttbr0_el1, x2 // now update TTBR0 + msr ttbr0_el1, x3 // now update TTBR0 isb b post_ttbr_update_workaround // Back to C code... ENDPROC(cpu_do_switch_mm) |