diff options
Diffstat (limited to 'arch/arm64/kernel/entry.S')
| -rw-r--r-- | arch/arm64/kernel/entry.S | 114 |
1 files changed, 45 insertions, 69 deletions
diff --git a/arch/arm64/kernel/entry.S b/arch/arm64/kernel/entry.S index 863d44f73028..bc6d5a970a13 100644 --- a/arch/arm64/kernel/entry.S +++ b/arch/arm64/kernel/entry.S @@ -29,16 +29,6 @@ #include <asm/asm-uaccess.h> #include <asm/unistd.h> -/* - * Context tracking and irqflag tracing need to instrument transitions between - * user and kernel mode. - */ - .macro user_enter_irqoff -#if defined(CONFIG_CONTEXT_TRACKING) || defined(CONFIG_TRACE_IRQFLAGS) - bl exit_to_user_mode -#endif - .endm - .macro clear_gp_regs .irp n,0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29 mov x\n, xzr @@ -133,42 +123,46 @@ alternative_cb_end .endm /* Check for MTE asynchronous tag check faults */ - .macro check_mte_async_tcf, tmp, ti_flags + .macro check_mte_async_tcf, tmp, ti_flags, thread_sctlr #ifdef CONFIG_ARM64_MTE .arch_extension lse alternative_if_not ARM64_MTE b 1f alternative_else_nop_endif + /* + * Asynchronous tag check faults are only possible in ASYNC (2) or + * ASYM (3) modes. In each of these modes bit 1 of SCTLR_EL1.TCF0 is + * set, so skip the check if it is unset. + */ + tbz \thread_sctlr, #(SCTLR_EL1_TCF0_SHIFT + 1), 1f mrs_s \tmp, SYS_TFSRE0_EL1 tbz \tmp, #SYS_TFSR_EL1_TF0_SHIFT, 1f /* Asynchronous TCF occurred for TTBR0 access, set the TI flag */ mov \tmp, #_TIF_MTE_ASYNC_FAULT add \ti_flags, tsk, #TSK_TI_FLAGS stset \tmp, [\ti_flags] - msr_s SYS_TFSRE0_EL1, xzr 1: #endif .endm /* Clear the MTE asynchronous tag check faults */ - .macro clear_mte_async_tcf + .macro clear_mte_async_tcf thread_sctlr #ifdef CONFIG_ARM64_MTE alternative_if ARM64_MTE + /* See comment in check_mte_async_tcf above. */ + tbz \thread_sctlr, #(SCTLR_EL1_TCF0_SHIFT + 1), 1f dsb ish msr_s SYS_TFSRE0_EL1, xzr +1: alternative_else_nop_endif #endif .endm - .macro mte_set_gcr, tmp, tmp2 + .macro mte_set_gcr, mte_ctrl, tmp #ifdef CONFIG_ARM64_MTE - /* - * Calculate and set the exclude mask preserving - * the RRND (bit[16]) setting. - */ - mrs_s \tmp2, SYS_GCR_EL1 - bfi \tmp2, \tmp, #0, #16 - msr_s SYS_GCR_EL1, \tmp2 + ubfx \tmp, \mte_ctrl, #MTE_CTRL_GCR_USER_EXCL_SHIFT, #16 + orr \tmp, \tmp, #SYS_GCR_EL1_RRND + msr_s SYS_GCR_EL1, \tmp #endif .endm @@ -177,10 +171,8 @@ alternative_else_nop_endif alternative_if_not ARM64_MTE b 1f alternative_else_nop_endif - ldr_l \tmp, gcr_kernel_excl - - mte_set_gcr \tmp, \tmp2 - isb + mov \tmp, KERNEL_GCR_EL1 + msr_s SYS_GCR_EL1, \tmp 1: #endif .endm @@ -190,7 +182,7 @@ alternative_else_nop_endif alternative_if_not ARM64_MTE b 1f alternative_else_nop_endif - ldr \tmp, [\tsk, #THREAD_GCR_EL1_USER] + ldr \tmp, [\tsk, #THREAD_MTE_CTRL] mte_set_gcr \tmp, \tmp2 1: @@ -231,8 +223,8 @@ alternative_else_nop_endif disable_step_tsk x19, x20 /* Check for asynchronous tag check faults in user space */ - check_mte_async_tcf x22, x23 - apply_ssbd 1, x22, x23 + ldr x0, [tsk, THREAD_SCTLR_USER] + check_mte_async_tcf x22, x23, x0 #ifdef CONFIG_ARM64_PTR_AUTH alternative_if ARM64_HAS_ADDRESS_AUTH @@ -245,7 +237,6 @@ alternative_if ARM64_HAS_ADDRESS_AUTH * was disabled on kernel exit then we would have left the kernel IA * installed so there is no need to install it again. */ - ldr x0, [tsk, THREAD_SCTLR_USER] tbz x0, SCTLR_ELx_ENIA_SHIFT, 1f __ptrauth_keys_install_kernel_nosync tsk, x20, x22, x23 b 2f @@ -254,12 +245,26 @@ alternative_if ARM64_HAS_ADDRESS_AUTH orr x0, x0, SCTLR_ELx_ENIA msr sctlr_el1, x0 2: - isb alternative_else_nop_endif #endif + apply_ssbd 1, x22, x23 + mte_set_kernel_gcr x22, x23 + /* + * Any non-self-synchronizing system register updates required for + * kernel entry should be placed before this point. + */ +alternative_if ARM64_MTE + isb + b 1f +alternative_else_nop_endif +alternative_if ARM64_HAS_ADDRESS_AUTH + isb +alternative_else_nop_endif +1: + scs_load tsk .else add x21, sp, #PT_REGS_SIZE @@ -362,6 +367,10 @@ alternative_else_nop_endif 3: scs_save tsk + /* Ignore asynchronous tag check faults in the uaccess routines */ + ldr x0, [tsk, THREAD_SCTLR_USER] + clear_mte_async_tcf x0 + #ifdef CONFIG_ARM64_PTR_AUTH alternative_if ARM64_HAS_ADDRESS_AUTH /* @@ -371,7 +380,6 @@ alternative_if ARM64_HAS_ADDRESS_AUTH * * No kernel C function calls after this. */ - ldr x0, [tsk, THREAD_SCTLR_USER] tbz x0, SCTLR_ELx_ENIA_SHIFT, 1f __ptrauth_keys_install_user tsk, x0, x1, x2 b 2f @@ -474,18 +482,6 @@ SYM_CODE_END(__swpan_exit_el0) /* GPRs used by entry code */ tsk .req x28 // current thread_info -/* - * Interrupt handling. - */ - .macro gic_prio_kentry_setup, tmp:req -#ifdef CONFIG_ARM64_PSEUDO_NMI - alternative_if ARM64_HAS_IRQ_PRIO_MASKING - mov \tmp, #(GIC_PRIO_PSR_I_SET | GIC_PRIO_IRQON) - msr_s SYS_ICC_PMR_EL1, \tmp - alternative_else_nop_endif -#endif - .endm - .text /* @@ -517,12 +513,13 @@ SYM_CODE_START(vectors) SYM_CODE_END(vectors) #ifdef CONFIG_VMAP_STACK +SYM_CODE_START_LOCAL(__bad_stack) /* * We detected an overflow in kernel_ventry, which switched to the * overflow stack. Stash the exception regs, and head to our overflow * handler. */ -__bad_stack: + /* Restore the original x0 value */ mrs x0, tpidrro_el0 @@ -542,6 +539,7 @@ __bad_stack: /* Time to die */ bl handle_bad_stack ASM_BUG() +SYM_CODE_END(__bad_stack) #endif /* CONFIG_VMAP_STACK */ @@ -585,37 +583,13 @@ SYM_CODE_START_LOCAL(ret_to_kernel) kernel_exit 1 SYM_CODE_END(ret_to_kernel) -/* - * "slow" syscall return path. - */ SYM_CODE_START_LOCAL(ret_to_user) - disable_daif - gic_prio_kentry_setup tmp=x3 -#ifdef CONFIG_TRACE_IRQFLAGS - bl trace_hardirqs_off -#endif - ldr x19, [tsk, #TSK_TI_FLAGS] - and x2, x19, #_TIF_WORK_MASK - cbnz x2, work_pending -finish_ret_to_user: - user_enter_irqoff - /* Ignore asynchronous tag check faults in the uaccess routines */ - clear_mte_async_tcf + ldr x19, [tsk, #TSK_TI_FLAGS] // re-check for single-step enable_step_tsk x19, x2 #ifdef CONFIG_GCC_PLUGIN_STACKLEAK bl stackleak_erase #endif kernel_exit 0 - -/* - * Ok, we need to do extra processing, enter the slow path. - */ -work_pending: - mov x0, sp // 'regs' - mov x1, x19 - bl do_notify_resume - ldr x19, [tsk, #TSK_TI_FLAGS] // re-check for single-step - b finish_ret_to_user SYM_CODE_END(ret_to_user) .popsection // .entry.text @@ -781,6 +755,8 @@ SYM_CODE_START(ret_from_fork) mov x0, x20 blr x19 1: get_current_task tsk + mov x0, sp + bl asm_exit_to_user_mode b ret_to_user SYM_CODE_END(ret_from_fork) NOKPROBE(ret_from_fork) |