diff options
Diffstat (limited to 'arch/arm/kernel/entry-common.S')
| -rw-r--r-- | arch/arm/kernel/entry-common.S | 188 |
1 files changed, 110 insertions, 78 deletions
diff --git a/arch/arm/kernel/entry-common.S b/arch/arm/kernel/entry-common.S index eb5cd77bf1d8..88336a1292bb 100644 --- a/arch/arm/kernel/entry-common.S +++ b/arch/arm/kernel/entry-common.S @@ -1,52 +1,51 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ /* * linux/arch/arm/kernel/entry-common.S * * Copyright (C) 2000 Russell King - * - * This program is free software; you can redistribute it and/or modify - * it under the terms of the GNU General Public License version 2 as - * published by the Free Software Foundation. */ #include <asm/assembler.h> #include <asm/unistd.h> #include <asm/ftrace.h> #include <asm/unwind.h> +#include <asm/page.h> #ifdef CONFIG_AEABI #include <asm/unistd-oabi.h> #endif .equ NR_syscalls, __NR_syscalls -#ifdef CONFIG_NEED_RET_TO_USER -#include <mach/entry-macro.S> -#else - .macro arch_ret_to_user, tmp1, tmp2 - .endm -#endif - #include "entry-header.S" +saved_psr .req r8 +#if defined(CONFIG_TRACE_IRQFLAGS) || defined(CONFIG_CONTEXT_TRACKING_USER) +saved_pc .req r9 +#define TRACE(x...) x +#else +saved_pc .req lr +#define TRACE(x...) +#endif + .section .entry.text,"ax",%progbits .align 5 -#if !(IS_ENABLED(CONFIG_TRACE_IRQFLAGS) || IS_ENABLED(CONFIG_CONTEXT_TRACKING)) +#if !(IS_ENABLED(CONFIG_TRACE_IRQFLAGS) || IS_ENABLED(CONFIG_CONTEXT_TRACKING_USER) || \ + IS_ENABLED(CONFIG_DEBUG_RSEQ)) /* * This is the fast syscall return path. We do as little as possible here, * such as avoiding writing r0 to the stack. We only use this path if we - * have tracing and context tracking disabled - the overheads from those - * features make this path too inefficient. + * have tracing, context tracking and rseq debug disabled - the overheads + * from those features make this path too inefficient. */ ret_fast_syscall: +__ret_fast_syscall: UNWIND(.fnstart ) UNWIND(.cantunwind ) disable_irq_notrace @ disable interrupts ldr r1, [tsk, #TI_FLAGS] @ re-check for syscall tracing - tst r1, #_TIF_SYSCALL_WORK | _TIF_WORK_MASK + movs r1, r1, lsl #16 bne fast_work_pending - /* perform architecture specific actions before user return */ - arch_ret_to_user r1, lr - restore_user_regs fast = 1, offset = S_OFF UNWIND(.fnend ) ENDPROC(ret_fast_syscall) @@ -57,17 +56,24 @@ fast_work_pending: /* fall through to work_pending */ #else /* - * The "replacement" ret_fast_syscall for when tracing or context tracking - * is enabled. As we will need to call out to some C functions, we save - * r0 first to avoid needing to save registers around each C function call. + * The "replacement" ret_fast_syscall for when tracing, context tracking, + * or rseq debug is enabled. As we will need to call out to some C functions, + * we save r0 first to avoid needing to save registers around each C function + * call. */ ret_fast_syscall: +__ret_fast_syscall: UNWIND(.fnstart ) UNWIND(.cantunwind ) str r0, [sp, #S_R0 + S_OFF]! @ save returned r0 +#if IS_ENABLED(CONFIG_DEBUG_RSEQ) + /* do_rseq_syscall needs interrupts enabled. */ + mov r0, sp @ 'regs' + bl do_rseq_syscall +#endif disable_irq_notrace @ disable interrupts ldr r1, [tsk, #TI_FLAGS] @ re-check for syscall tracing - tst r1, #_TIF_SYSCALL_WORK | _TIF_WORK_MASK + movs r1, r1, lsl #16 beq no_work_pending UNWIND(.fnend ) ENDPROC(ret_fast_syscall) @@ -84,6 +90,7 @@ slow_work_pending: cmp r0, #0 beq no_work_pending movlt scno, #(__NR_restart_syscall - __NR_SYSCALL_BASE) + str scno, [tsk, #TI_ABI_SYSCALL] @ make sure tracers see update ldmia sp, {r0 - r6} @ have to reload r0 - r6 b local_restart @ ... and off we go ENDPROC(ret_fast_syscall) @@ -96,18 +103,25 @@ ENDPROC(ret_fast_syscall) */ ENTRY(ret_to_user) ret_slow_syscall: +#if IS_ENABLED(CONFIG_DEBUG_RSEQ) + /* do_rseq_syscall needs interrupts enabled. */ + enable_irq_notrace @ enable interrupts + mov r0, sp @ 'regs' + bl do_rseq_syscall +#endif disable_irq_notrace @ disable interrupts ENTRY(ret_to_user_from_irq) ldr r1, [tsk, #TI_FLAGS] - tst r1, #_TIF_WORK_MASK + movs r1, r1, lsl #16 bne slow_work_pending no_work_pending: asm_trace_hardirqs_on save = 0 - /* perform architecture specific actions before user return */ - arch_ret_to_user r1, lr ct_user_enter save = 0 +#ifdef CONFIG_KSTACK_ERASE + bl stackleak_erase_on_task_stack +#endif restore_user_regs fast = 0, offset = 0 ENDPROC(ret_to_user_from_irq) ENDPROC(ret_to_user) @@ -131,26 +145,52 @@ ENDPROC(ret_from_fork) */ .align 5 +#ifdef CONFIG_HARDEN_BRANCH_HISTORY +ENTRY(vector_bhb_loop8_swi) + sub sp, sp, #PT_REGS_SIZE + stmia sp, {r0 - r12} + mov r8, #8 +1: b 2f +2: subs r8, r8, #1 + bne 1b + dsb nsh + isb + b 3f +ENDPROC(vector_bhb_loop8_swi) + + .align 5 +ENTRY(vector_bhb_bpiall_swi) + sub sp, sp, #PT_REGS_SIZE + stmia sp, {r0 - r12} + mcr p15, 0, r8, c7, c5, 6 @ BPIALL + isb + b 3f +ENDPROC(vector_bhb_bpiall_swi) +#endif + .align 5 ENTRY(vector_swi) #ifdef CONFIG_CPU_V7M v7m_exception_entry #else sub sp, sp, #PT_REGS_SIZE stmia sp, {r0 - r12} @ Calling r0 - r12 +3: ARM( add r8, sp, #S_PC ) ARM( stmdb r8, {sp, lr}^ ) @ Calling sp, lr THUMB( mov r8, sp ) THUMB( store_user_sp_lr r8, r10, S_SP ) @ calling sp, lr - mrs r8, spsr @ called from non-FIQ mode, so ok. - str lr, [sp, #S_PC] @ Save calling PC - str r8, [sp, #S_PSR] @ Save CPSR + mrs saved_psr, spsr @ called from non-FIQ mode, so ok. + TRACE( mov saved_pc, lr ) + str saved_pc, [sp, #S_PC] @ Save calling PC + str saved_psr, [sp, #S_PSR] @ Save CPSR str r0, [sp, #S_OLD_R0] @ Save OLD_R0 #endif + reload_current r10, ip zero_fp - alignment_trap r10, ip, __cr_alignment - enable_irq - ct_user_exit - get_thread_info tsk + alignment_trap r10, ip, cr_alignment + asm_trace_hardirqs_on save=0 + enable_irq_notrace + ct_user_exit save=0 /* * Get the system call number. @@ -163,11 +203,11 @@ ENTRY(vector_swi) * value to determine if it is an EABI or an old ABI call. */ #ifdef CONFIG_ARM_THUMB - tst r8, #PSR_T_BIT + tst saved_psr, #PSR_T_BIT movne r10, #0 @ no thumb OABI emulation - USER( ldreq r10, [lr, #-4] ) @ get SWI instruction + USER( ldreq r10, [saved_pc, #-4] ) @ get SWI instruction #else - USER( ldr r10, [lr, #-4] ) @ get SWI instruction + USER( ldr r10, [saved_pc, #-4] ) @ get SWI instruction #endif ARM_BE8(rev r10, r10) @ little endian instruction @@ -178,16 +218,19 @@ ENTRY(vector_swi) */ #elif defined(CONFIG_ARM_THUMB) /* Legacy ABI only, possibly thumb mode. */ - tst r8, #PSR_T_BIT @ this is SPSR from save_user_regs + tst saved_psr, #PSR_T_BIT @ this is SPSR from save_user_regs addne scno, r7, #__NR_SYSCALL_BASE @ put OS number in - USER( ldreq scno, [lr, #-4] ) + USER( ldreq scno, [saved_pc, #-4] ) #else /* Legacy ABI only. */ - USER( ldr scno, [lr, #-4] ) @ get SWI instruction + USER( ldr scno, [saved_pc, #-4] ) @ get SWI instruction #endif + /* saved_psr and saved_pc are now dead */ + uaccess_disable tbl + get_thread_info tsk adr tbl, sys_call_table @ load syscall table pointer @@ -199,12 +242,22 @@ ENTRY(vector_swi) * get the old ABI syscall table address. */ bics r10, r10, #0xff000000 + strne r10, [tsk, #TI_ABI_SYSCALL] + streq scno, [tsk, #TI_ABI_SYSCALL] eorne scno, r10, #__NR_OABI_SYSCALL_BASE ldrne tbl, =sys_oabi_call_table #elif !defined(CONFIG_AEABI) bic scno, scno, #0xff000000 @ mask off SWI op-code + str scno, [tsk, #TI_ABI_SYSCALL] eor scno, scno, #__NR_SYSCALL_BASE @ check OS number +#else + str scno, [tsk, #TI_ABI_SYSCALL] #endif + /* + * Reload the registers that may have been corrupted on entry to + * the syscall assembly (by tracing or context tracking.) + */ + TRACE( ldmia sp, {r0 - r3} ) local_restart: ldr r10, [tsk, #TI_FLAGS] @ check for syscall tracing @@ -213,9 +266,7 @@ local_restart: tst r10, #_TIF_SYSCALL_WORK @ are we tracing syscalls? bne __sys_trace - cmp scno, #NR_syscalls @ check upper syscall limit - badr lr, ret_fast_syscall @ return address - ldrcc pc, [tbl, scno, lsl #2] @ call sys_* routine + invoke_syscall tbl, scno, r10, __ret_fast_syscall add r1, sp, #S_OFF 2: cmp scno, #(__ARM_NR_BASE - __NR_SYSCALL_BASE) @@ -234,53 +285,39 @@ local_restart: * current task. */ 9001: - sub lr, lr, #4 + sub lr, saved_pc, #4 str lr, [sp, #S_PC] + get_thread_info tsk b ret_fast_syscall #endif ENDPROC(vector_swi) + .ltorg /* * This is the really slow path. We're going to be doing * context switches, and waiting for our parent to respond. */ __sys_trace: - mov r1, scno add r0, sp, #S_OFF bl syscall_trace_enter - - badr lr, __sys_trace_return @ return address - mov scno, r0 @ syscall number (possibly new) - add r1, sp, #S_R0 + S_OFF @ pointer to regs - cmp scno, #NR_syscalls @ check upper syscall limit - ldmccia r1, {r0 - r6} @ have to reload r0 - r6 - stmccia sp, {r4, r5} @ and update the stack args - ldrcc pc, [tbl, scno, lsl #2] @ call sys_* routine + mov scno, r0 + invoke_syscall tbl, scno, r10, __sys_trace_return, reload=1 cmp scno, #-1 @ skip the syscall? bne 2b add sp, sp, #S_OFF @ restore stack - b ret_slow_syscall -__sys_trace_return: - str r0, [sp, #S_R0 + S_OFF]! @ save returned r0 +__sys_trace_return_nosave: + enable_irq_notrace mov r0, sp bl syscall_trace_exit b ret_slow_syscall -__sys_trace_return_nosave: - enable_irq_notrace +__sys_trace_return: + str r0, [sp, #S_R0 + S_OFF]! @ save returned r0 mov r0, sp bl syscall_trace_exit b ret_slow_syscall - .align 5 -#ifdef CONFIG_ALIGNMENT_TRAP - .type __cr_alignment, #object -__cr_alignment: - .word cr_alignment -#endif - .ltorg - .macro syscall_table_start, sym .equ __sys_nr, 0 .type \sym, #object @@ -308,20 +345,19 @@ ENTRY(\sym) .size \sym, . - \sym .endm -#define NATIVE(nr, func) syscall nr, func +#define __SYSCALL_WITH_COMPAT(nr, native, compat) __SYSCALL(nr, native) +#define __SYSCALL(nr, func) syscall nr, func /* * This is the syscall table declaration for native ABI syscalls. * With EABI a couple syscalls are obsolete and defined as sys_ni_syscall. */ syscall_table_start sys_call_table -#define COMPAT(nr, native, compat) syscall nr, native #ifdef CONFIG_AEABI #include <calls-eabi.S> #else #include <calls-oabi.S> #endif -#undef COMPAT syscall_table_end sys_call_table /*============================================================================ @@ -333,7 +369,11 @@ sys_syscall: bic scno, r0, #__NR_OABI_SYSCALL_BASE cmp scno, #__NR_syscall - __NR_SYSCALL_BASE cmpne scno, #NR_syscalls @ check range - stmloia sp, {r5, r6} @ shuffle args +#ifdef CONFIG_CPU_SPECTRE + movhs scno, #0 + csdb +#endif + stmialo sp, {r5, r6} @ shuffle args movlo r0, r1 movlo r1, r2 movlo r2, r3 @@ -371,17 +411,8 @@ ENDPROC(sys_fstatfs64_wrapper) * offset, we return EINVAL. */ sys_mmap2: -#if PAGE_SHIFT > 12 - tst r5, #PGOFF_MASK - moveq r5, r5, lsr #PAGE_SHIFT - 12 - streq r5, [sp, #4] - beq sys_mmap_pgoff - mov r0, #-EINVAL - ret lr -#else str r5, [sp, #4] b sys_mmap_pgoff -#endif ENDPROC(sys_mmap2) #ifdef CONFIG_OABI_COMPAT @@ -424,7 +455,8 @@ ENDPROC(sys_oabi_readahead) * using the compatibility syscall entries. */ syscall_table_start sys_oabi_call_table -#define COMPAT(nr, native, compat) syscall nr, compat +#undef __SYSCALL_WITH_COMPAT +#define __SYSCALL_WITH_COMPAT(nr, native, compat) __SYSCALL(nr, compat) #include <calls-oabi.S> syscall_table_end sys_oabi_call_table |