diff options
Diffstat (limited to 'arch/powerpc/kernel/entry_32.S')
| -rw-r--r-- | arch/powerpc/kernel/entry_32.S | 193 |
1 files changed, 101 insertions, 92 deletions
diff --git a/arch/powerpc/kernel/entry_32.S b/arch/powerpc/kernel/entry_32.S index b61cfd29c76f..85fdb6d879f1 100644 --- a/arch/powerpc/kernel/entry_32.S +++ b/arch/powerpc/kernel/entry_32.S @@ -1,3 +1,4 @@ +/* SPDX-License-Identifier: GPL-2.0-or-later */ /* * PowerPC version * Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org) @@ -11,12 +12,6 @@ * * This file contains the system call entry code, context switch * code, and exception/interrupt return code for PowerPC. - * - * This program is free software; you can redistribute it and/or - * modify it under the terms of the GNU General Public License - * as published by the Free Software Foundation; either version - * 2 of the License, or (at your option) any later version. - * */ #include <linux/errno.h> @@ -36,15 +31,10 @@ #include <asm/asm-405.h> #include <asm/feature-fixups.h> #include <asm/barrier.h> +#include <asm/kup.h> +#include <asm/bug.h> -/* - * MSR_KERNEL is > 0x10000 on 4xx/Book-E since it include MSR_CE. - */ -#if MSR_KERNEL >= 0x10000 -#define LOAD_MSR_KERNEL(r, x) lis r,(x)@h; ori r,r,(x)@l -#else -#define LOAD_MSR_KERNEL(r, x) li r,(x) -#endif +#include "head_32.h" /* * Align to 4k in order to ensure that all functions modyfing srr0/srr1 @@ -150,8 +140,8 @@ transfer_to_handler: stw r12,_CTR(r11) stw r2,_XER(r11) mfspr r12,SPRN_SPRG_THREAD - addi r2,r12,-THREAD beq 2f /* if from user, fix up THREAD.regs */ + addi r2, r12, -THREAD addi r11,r1,STACK_FRAME_OVERHEAD stw r11,PT_REGS(r12) #if defined(CONFIG_40x) || defined(CONFIG_BOOKE) @@ -161,6 +151,9 @@ transfer_to_handler: andis. r12,r12,DBCR0_IDM@h #endif ACCOUNT_CPU_USER_ENTRY(r2, r11, r12) +#ifdef CONFIG_PPC_BOOK3S_32 + kuep_lock r11, r12 +#endif #if defined(CONFIG_40x) || defined(CONFIG_BOOKE) beq+ 3f /* From user and task is ptraced - load up global dbcr0 */ @@ -186,6 +179,8 @@ transfer_to_handler: 2: /* if from kernel, check interrupted DOZE/NAP mode and * check for stack overflow */ + kuap_save_and_lock r11, r12, r9, r2, r0 + addi r2, r12, -THREAD lwz r9,KSP_LIMIT(r12) cmplw r1,r9 /* if r1 <= ksp_limit */ ble- stack_ovf /* then the kernel stack overflowed */ @@ -207,26 +202,43 @@ transfer_to_handler_cont: mtspr SPRN_NRI, r0 #endif #ifdef CONFIG_TRACE_IRQFLAGS + /* + * When tracing IRQ state (lockdep) we enable the MMU before we call + * the IRQ tracing functions as they might access vmalloc space or + * perform IOs for console output. + * + * To speed up the syscall path where interrupts stay on, let's check + * first if we are changing the MSR value at all. + */ + tophys(r12, r1) + lwz r12,_MSR(r12) + andi. r12,r12,MSR_EE + bne 1f + + /* MSR isn't changing, just transition directly */ +#endif + mtspr SPRN_SRR0,r11 + mtspr SPRN_SRR1,r10 + mtlr r9 + SYNC + RFI /* jump to handler, enable MMU */ + +#ifdef CONFIG_TRACE_IRQFLAGS +1: /* MSR is changing, re-enable MMU so we can notify lockdep. We need to + * keep interrupts disabled at this point otherwise we might risk + * taking an interrupt before we tell lockdep they are enabled. + */ lis r12,reenable_mmu@h ori r12,r12,reenable_mmu@l + LOAD_MSR_KERNEL(r0, MSR_KERNEL) mtspr SPRN_SRR0,r12 - mtspr SPRN_SRR1,r10 + mtspr SPRN_SRR1,r0 SYNC RFI -reenable_mmu: /* re-enable mmu so we can */ - mfmsr r10 - lwz r12,_MSR(r1) - xor r10,r10,r12 - andi. r10,r10,MSR_EE /* Did EE change? */ - beq 1f +reenable_mmu: /* - * The trace_hardirqs_off will use CALLER_ADDR0 and CALLER_ADDR1. - * If from user mode there is only one stack frame on the stack, and - * accessing CALLER_ADDR1 will cause oops. So we need create a dummy - * stack frame to make trace_hardirqs_off happy. - * - * This is handy because we also need to save a bunch of GPRs, + * We save a bunch of GPRs, * r3 can be different from GPR3(r1) at this point, r9 and r11 * contains the old MSR and handler address respectively, * r4 & r5 can contain page fault arguments that need to be passed @@ -234,14 +246,19 @@ reenable_mmu: /* re-enable mmu so we can */ * they aren't useful past this point (aren't syscall arguments), * the rest is restored from the exception frame. */ + stwu r1,-32(r1) stw r9,8(r1) stw r11,12(r1) stw r3,16(r1) stw r4,20(r1) stw r5,24(r1) - bl trace_hardirqs_off - lwz r5,24(r1) + + /* If we are disabling interrupts (normal case), simply log it with + * lockdep + */ +1: bl trace_hardirqs_off +2: lwz r5,24(r1) lwz r4,20(r1) lwz r3,16(r1) lwz r11,12(r1) @@ -251,15 +268,9 @@ reenable_mmu: /* re-enable mmu so we can */ lwz r6,GPR6(r1) lwz r7,GPR7(r1) lwz r8,GPR8(r1) -1: mtctr r11 + mtctr r11 mtlr r9 bctr /* jump to handler */ -#else /* CONFIG_TRACE_IRQFLAGS */ - mtspr SPRN_SRR0,r11 - mtspr SPRN_SRR1,r10 - mtlr r9 - SYNC - RFI /* jump to handler, enable MMU */ #endif /* CONFIG_TRACE_IRQFLAGS */ #if defined (CONFIG_PPC_BOOK3S_32) || defined(CONFIG_E500) @@ -272,6 +283,7 @@ reenable_mmu: /* re-enable mmu so we can */ lwz r9,_MSR(r11) /* if sleeping, clear MSR.EE */ rlwinm r9,r9,0,~MSR_EE lwz r12,_LINK(r11) /* and return to address in LR */ + kuap_restore r11, r2, r3, r4, r5 b fast_exception_return #endif @@ -301,6 +313,33 @@ stack_ovf: SYNC RFI +#ifdef CONFIG_TRACE_IRQFLAGS +trace_syscall_entry_irq_off: + /* + * Syscall shouldn't happen while interrupts are disabled, + * so let's do a warning here. + */ +0: trap + EMIT_BUG_ENTRY 0b,__FILE__,__LINE__, BUGFLAG_WARNING + bl trace_hardirqs_on + + /* Now enable for real */ + LOAD_MSR_KERNEL(r10, MSR_KERNEL | MSR_EE) + mtmsr r10 + + REST_GPR(0, r1) + REST_4GPRS(3, r1) + REST_2GPRS(7, r1) + b DoSyscall +#endif /* CONFIG_TRACE_IRQFLAGS */ + + .globl transfer_to_syscall +transfer_to_syscall: +#ifdef CONFIG_TRACE_IRQFLAGS + andi. r12,r9,MSR_EE + beq- trace_syscall_entry_irq_off +#endif /* CONFIG_TRACE_IRQFLAGS */ + /* * Handle a system call. */ @@ -312,33 +351,14 @@ _GLOBAL(DoSyscall) stw r3,ORIG_GPR3(r1) li r12,0 stw r12,RESULT(r1) - lwz r11,_CCR(r1) /* Clear SO bit in CR */ - rlwinm r11,r11,0,4,2 - stw r11,_CCR(r1) #ifdef CONFIG_TRACE_IRQFLAGS - /* Return from syscalls can (and generally will) hard enable - * interrupts. You aren't supposed to call a syscall with - * interrupts disabled in the first place. However, to ensure - * that we get it right vs. lockdep if it happens, we force - * that hard enable here with appropriate tracing if we see - * that we have been called with interrupts off - */ + /* Make sure interrupts are enabled */ mfmsr r11 andi. r12,r11,MSR_EE - bne+ 1f - /* We came in with interrupts disabled, we enable them now */ - bl trace_hardirqs_on - mfmsr r11 - lwz r0,GPR0(r1) - lwz r3,GPR3(r1) - lwz r4,GPR4(r1) - ori r11,r11,MSR_EE - lwz r5,GPR5(r1) - lwz r6,GPR6(r1) - lwz r7,GPR7(r1) - lwz r8,GPR8(r1) - mtmsr r11 -1: + /* We came in with interrupts disabled, we WARN and mark them enabled + * for lockdep now */ +0: tweqi r12, 0 + EMIT_BUG_ENTRY 0b,__FILE__,__LINE__, BUGFLAG_WARNING #endif /* CONFIG_TRACE_IRQFLAGS */ lwz r11,TI_FLAGS(r2) andi. r11,r11,_TIF_SYSCALL_DOTRACE @@ -392,8 +412,7 @@ syscall_exit_cont: lwz r8,_MSR(r1) #ifdef CONFIG_TRACE_IRQFLAGS /* If we are going to return from the syscall with interrupts - * off, we trace that here. It shouldn't happen though but we - * want to catch the bugger if it does right ? + * off, we trace that here. It shouldn't normally happen. */ andi. r10,r8,MSR_EE bne+ 1f @@ -422,12 +441,11 @@ BEGIN_FTR_SECTION lwarx r7,0,r1 END_FTR_SECTION_IFSET(CPU_FTR_NEED_PAIRED_STWCX) stwcx. r0,0,r1 /* to clear the reservation */ -#ifdef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE - andi. r4,r8,MSR_PR - beq 3f ACCOUNT_CPU_USER_EXIT(r2, r5, r7) -3: +#ifdef CONFIG_PPC_BOOK3S_32 + kuep_unlock r5, r7 #endif + kuap_check r2, r4 lwz r4,_LINK(r1) lwz r5,_CCR(r1) mtlr r4 @@ -678,6 +696,7 @@ END_FTR_SECTION_IFSET(CPU_FTR_SPE) stw r10,_CCR(r1) stw r1,KSP(r3) /* Set old stack pointer */ + kuap_check r2, r4 #ifdef CONFIG_SMP /* We need a sync somewhere here to make sure that if the * previous task gets rescheduled on another CPU, it sees all @@ -820,6 +839,9 @@ restore_user: bnel- load_dbcr0 #endif ACCOUNT_CPU_USER_EXIT(r2, r10, r11) +#ifdef CONFIG_PPC_BOOK3S_32 + kuep_unlock r10, r11 +#endif b restore @@ -866,12 +888,12 @@ resume_kernel: /* check current_thread_info->preempt_count */ lwz r0,TI_PREEMPT(r2) cmpwi 0,r0,0 /* if non-zero, just restore regs and return */ - bne restore + bne restore_kuap andi. r8,r8,_TIF_NEED_RESCHED - beq+ restore + beq+ restore_kuap lwz r3,_MSR(r1) andi. r0,r3,MSR_EE /* interrupts off? */ - beq restore /* don't schedule if so */ + beq restore_kuap /* don't schedule if so */ #ifdef CONFIG_TRACE_IRQFLAGS /* Lockdep thinks irqs are enabled, we need to call * preempt_schedule_irq with IRQs off, so we inform lockdep @@ -879,10 +901,7 @@ resume_kernel: */ bl trace_hardirqs_off #endif -1: bl preempt_schedule_irq - lwz r3,TI_FLAGS(r2) - andi. r0,r3,_TIF_NEED_RESCHED - bne- 1b + bl preempt_schedule_irq #ifdef CONFIG_TRACE_IRQFLAGS /* And now, to properly rebalance the above, we tell lockdep they * are being turned back on, which will happen when we return @@ -890,6 +909,8 @@ resume_kernel: bl trace_hardirqs_on #endif #endif /* CONFIG_PREEMPT */ +restore_kuap: + kuap_restore r1, r2, r9, r10, r0 /* interrupts are hard-disabled at this point */ restore: @@ -913,28 +934,14 @@ END_MMU_FTR_SECTION_IFSET(MMU_FTR_TYPE_47x) * off in this assembly code while peeking at TI_FLAGS() and such. However * we need to inform it if the exception turned interrupts off, and we * are about to trun them back on. - * - * The problem here sadly is that we don't know whether the exceptions was - * one that turned interrupts off or not. So we always tell lockdep about - * turning them on here when we go back to wherever we came from with EE - * on, even if that may meen some redudant calls being tracked. Maybe later - * we could encode what the exception did somewhere or test the exception - * type in the pt_regs but that sounds overkill */ andi. r10,r9,MSR_EE beq 1f - /* - * Since the ftrace irqsoff latency trace checks CALLER_ADDR1, - * which is the stack frame here, we need to force a stack frame - * in case we came from user space. - */ stwu r1,-32(r1) mflr r0 stw r0,4(r1) - stwu r1,-32(r1) bl trace_hardirqs_on - lwz r1,0(r1) - lwz r1,0(r1) + addi r1, r1, 32 lwz r9,_MSR(r1) 1: #endif /* CONFIG_TRACE_IRQFLAGS */ @@ -1197,6 +1204,7 @@ load_dbcr0: .section .bss .align 4 + .global global_dbcr0 global_dbcr0: .space 8*NR_CPUS .previous @@ -1207,9 +1215,10 @@ do_work: /* r10 contains MSR_KERNEL here */ beq do_user_signal do_resched: /* r10 contains MSR_KERNEL here */ - /* Note: We don't need to inform lockdep that we are enabling - * interrupts here. As far as it knows, they are already enabled - */ +#ifdef CONFIG_TRACE_IRQFLAGS + bl trace_hardirqs_on + mfmsr r10 +#endif ori r10,r10,MSR_EE SYNC MTMSRD(r10) /* hard-enable interrupts */ |