diff options
Diffstat (limited to 'arch/arm64/kernel/entry.S')
| -rw-r--r-- | arch/arm64/kernel/entry.S | 122 |
1 files changed, 66 insertions, 56 deletions
diff --git a/arch/arm64/kernel/entry.S b/arch/arm64/kernel/entry.S index cace76d17535..0b8461158c56 100644 --- a/arch/arm64/kernel/entry.S +++ b/arch/arm64/kernel/entry.S @@ -111,6 +111,18 @@ mrs x23, spsr_el1 stp lr, x21, [sp, #S_LR] + /* + * In order to be able to dump the contents of struct pt_regs at the + * time the exception was taken (in case we attempt to walk the call + * stack later), chain it together with the stack frames. + */ + .if \el == 0 + stp xzr, xzr, [sp, #S_STACKFRAME] + .else + stp x29, x22, [sp, #S_STACKFRAME] + .endif + add x29, sp, #S_STACKFRAME + #ifdef CONFIG_ARM64_SW_TTBR0_PAN /* * Set the TTBR0 PAN bit in SPSR. When the exception is taken from @@ -263,14 +275,6 @@ alternative_else_nop_endif /* switch to the irq stack */ mov sp, x26 - - /* - * Add a dummy stack frame, this non-standard format is fixed up - * by unwind_frame() - */ - stp x29, x19, [sp, #-16]! - mov x29, sp - 9998: .endm @@ -350,7 +354,8 @@ END(vectors) mov x0, sp mov x1, #\reason mrs x2, esr_el1 - b bad_mode + bl bad_mode + ASM_BUG() .endm el0_sync_invalid: @@ -447,14 +452,16 @@ el1_sp_pc: mrs x0, far_el1 enable_dbg mov x2, sp - b do_sp_pc_abort + bl do_sp_pc_abort + ASM_BUG() el1_undef: /* * Undefined instruction */ enable_dbg mov x0, sp - b do_undefinstr + bl do_undefinstr + ASM_BUG() el1_dbg: /* * Debug exception handling @@ -472,7 +479,8 @@ el1_inv: mov x0, sp mov x2, x1 mov x1, #BAD_SYNC - b bad_mode + bl bad_mode + ASM_BUG() ENDPROC(el1_sync) .align 6 @@ -706,38 +714,6 @@ el0_irq_naked: ENDPROC(el0_irq) /* - * Register switch for AArch64. The callee-saved registers need to be saved - * and restored. On entry: - * x0 = previous task_struct (must be preserved across the switch) - * x1 = next task_struct - * Previous and next are guaranteed not to be the same. - * - */ -ENTRY(cpu_switch_to) - mov x10, #THREAD_CPU_CONTEXT - add x8, x0, x10 - mov x9, sp - stp x19, x20, [x8], #16 // store callee-saved registers - stp x21, x22, [x8], #16 - stp x23, x24, [x8], #16 - stp x25, x26, [x8], #16 - stp x27, x28, [x8], #16 - stp x29, x9, [x8], #16 - str lr, [x8] - add x8, x1, x10 - ldp x19, x20, [x8], #16 // restore callee-saved registers - ldp x21, x22, [x8], #16 - ldp x23, x24, [x8], #16 - ldp x25, x26, [x8], #16 - ldp x27, x28, [x8], #16 - ldp x29, x9, [x8], #16 - ldr lr, [x8] - mov sp, x9 - msr sp_el0, x1 - ret -ENDPROC(cpu_switch_to) - -/* * This is the fast syscall return path. We do as little as possible here, * and this includes saving x0 back into the kernel stack. */ @@ -780,18 +756,6 @@ finish_ret_to_user: ENDPROC(ret_to_user) /* - * This is how we return from a fork. - */ -ENTRY(ret_from_fork) - bl schedule_tail - cbz x19, 1f // not a kernel thread - mov x0, x20 - blr x19 -1: get_thread_info tsk - b ret_to_user -ENDPROC(ret_from_fork) - -/* * SVC handler. */ .align 6 @@ -863,3 +827,49 @@ ENTRY(sys_rt_sigreturn_wrapper) mov x0, sp b sys_rt_sigreturn ENDPROC(sys_rt_sigreturn_wrapper) + +/* + * Register switch for AArch64. The callee-saved registers need to be saved + * and restored. On entry: + * x0 = previous task_struct (must be preserved across the switch) + * x1 = next task_struct + * Previous and next are guaranteed not to be the same. + * + */ +ENTRY(cpu_switch_to) + mov x10, #THREAD_CPU_CONTEXT + add x8, x0, x10 + mov x9, sp + stp x19, x20, [x8], #16 // store callee-saved registers + stp x21, x22, [x8], #16 + stp x23, x24, [x8], #16 + stp x25, x26, [x8], #16 + stp x27, x28, [x8], #16 + stp x29, x9, [x8], #16 + str lr, [x8] + add x8, x1, x10 + ldp x19, x20, [x8], #16 // restore callee-saved registers + ldp x21, x22, [x8], #16 + ldp x23, x24, [x8], #16 + ldp x25, x26, [x8], #16 + ldp x27, x28, [x8], #16 + ldp x29, x9, [x8], #16 + ldr lr, [x8] + mov sp, x9 + msr sp_el0, x1 + ret +ENDPROC(cpu_switch_to) +NOKPROBE(cpu_switch_to) + +/* + * This is how we return from a fork. + */ +ENTRY(ret_from_fork) + bl schedule_tail + cbz x19, 1f // not a kernel thread + mov x0, x20 + blr x19 +1: get_thread_info tsk + b ret_to_user +ENDPROC(ret_from_fork) +NOKPROBE(ret_from_fork) |