diff options
Diffstat (limited to 'arch/arm/kernel/entry-common.S')
| -rw-r--r-- | arch/arm/kernel/entry-common.S | 43 |
1 files changed, 26 insertions, 17 deletions
diff --git a/arch/arm/kernel/entry-common.S b/arch/arm/kernel/entry-common.S index 3c4f88701f22..106a1466518d 100644 --- a/arch/arm/kernel/entry-common.S +++ b/arch/arm/kernel/entry-common.S @@ -39,12 +39,13 @@ saved_pc .req lr .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) || \ + 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: UNWIND(.fnstart ) @@ -71,14 +72,20 @@ 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: 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 r2, [tsk, #TI_ADDR_LIMIT] cmp r2, #TASK_SIZE @@ -113,6 +120,12 @@ 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 r2, [tsk, #TI_ADDR_LIMIT] @@ -242,9 +255,7 @@ 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) @@ -278,14 +289,8 @@ __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 @@ -363,6 +368,10 @@ sys_syscall: bic scno, r0, #__NR_OABI_SYSCALL_BASE cmp scno, #__NR_syscall - __NR_SYSCALL_BASE cmpne scno, #NR_syscalls @ check range +#ifdef CONFIG_CPU_SPECTRE + movhs scno, #0 + csdb +#endif stmloia sp, {r5, r6} @ shuffle args movlo r0, r1 movlo r1, r2 |