diff options
Diffstat (limited to 'arch/arm64')
| -rw-r--r-- | arch/arm64/Kconfig | 26 | ||||
| -rw-r--r-- | arch/arm64/include/asm/kvm_mmu.h | 1 | ||||
| -rw-r--r-- | arch/arm64/kernel/entry.S | 11 | ||||
| -rw-r--r-- | arch/arm64/kernel/vdso/Makefile | 2 | ||||
| -rw-r--r-- | arch/arm64/kvm/sys_regs.c | 2 |
5 files changed, 39 insertions, 3 deletions
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig index 0c9e4d1086f7..196d179119ff 100644 --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -161,6 +161,32 @@ endmenu menu "Kernel Features" +menu "ARM errata workarounds" + +config ARM64_ERRATUM_845719 + bool "Cortex-A53: 845719: a load might read incorrect data" + depends on COMPAT + default n + help + This option adds an alternative code sequence to work around ARM + erratum 845719 on Cortex-A53 parts up to r0p4. + + When running a compat (AArch32) userspace on an affected Cortex-A53 + part, a load at EL0 from a virtual address that matches the bottom 32 + bits of the virtual address used by a recent load at (AArch64) EL1 + might return incorrect data. + + The workaround is to write the contextidr_el1 register on exception + return to a 32-bit task. + Please note that this does not necessarily enable the workaround, + as it depends on the alternative framework, which will only patch + the kernel if an affected CPU is detected. + + If unsure, say Y. + +endmenu + + config ARM64_64K_PAGES bool "Enable 64KB pages support" help diff --git a/arch/arm64/include/asm/kvm_mmu.h b/arch/arm64/include/asm/kvm_mmu.h index a030d163840b..84bfe94f43c3 100644 --- a/arch/arm64/include/asm/kvm_mmu.h +++ b/arch/arm64/include/asm/kvm_mmu.h @@ -125,7 +125,6 @@ static inline bool kvm_page_empty(void *ptr) #endif #define kvm_pud_table_empty(pudp) (0) - struct kvm; #define kvm_flush_dcache_to_poc(a,l) __flush_dcache_area((a), (l)) diff --git a/arch/arm64/kernel/entry.S b/arch/arm64/kernel/entry.S index 34ac40e49acc..68a9af639ae2 100644 --- a/arch/arm64/kernel/entry.S +++ b/arch/arm64/kernel/entry.S @@ -116,6 +116,17 @@ .if \el == 0 ct_user_enter ldr x23, [sp, #S_SP] // load return stack pointer +#ifdef CONFIG_ARM64_ERRATUM_845719 + tbz x22, #4, 1f +#ifdef CONFIG_PID_IN_CONTEXTIDR + mrs x29, contextidr_el1 + msr contextidr_el1, x29 +1: +#else + msr contextidr_el1, xzr +1: +#endif +#endif .endif .if \ret ldr x1, [sp, #S_X1] // preserve x0 (syscall return) diff --git a/arch/arm64/kernel/vdso/Makefile b/arch/arm64/kernel/vdso/Makefile index 84b942612051..ff3bddea482d 100644 --- a/arch/arm64/kernel/vdso/Makefile +++ b/arch/arm64/kernel/vdso/Makefile @@ -43,7 +43,7 @@ $(obj)/vdso-offsets.h: $(obj)/vdso.so.dbg FORCE $(call if_changed,vdsosym) # Assembly rules for the .S files -$(obj-vdso): %.o: %.S +$(obj-vdso): %.o: %.S FORCE $(call if_changed_dep,vdsoas) # Actual build commands diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c index 4cc3b719208e..c02d26e43757 100644 --- a/arch/arm64/kvm/sys_regs.c +++ b/arch/arm64/kvm/sys_regs.c @@ -652,7 +652,7 @@ static const struct sys_reg_desc cp14_64_regs[] = { * register). */ static const struct sys_reg_desc cp15_regs[] = { - { Op1( 0), CRn( 1), CRm( 0), Op2( 0), access_sctlr, NULL, c1_SCTLR }, + { Op1( 0), CRn( 1), CRm( 0), Op2( 0), access_sctlr, NULL, c1_SCTLR }, { Op1( 0), CRn( 2), CRm( 0), Op2( 0), access_vm_reg, NULL, c2_TTBR0 }, { Op1( 0), CRn( 2), CRm( 0), Op2( 1), access_vm_reg, NULL, c2_TTBR1 }, { Op1( 0), CRn( 2), CRm( 0), Op2( 2), access_vm_reg, NULL, c2_TTBCR }, |