#include #include #ifdef CONFIG_PPC_BOOK3S #include #else #include #endif #include #include #include #include #include #include #include .align 7 .macro DEBUG_SRR_VALID srr #ifdef CONFIG_PPC_RFI_SRR_DEBUG .ifc \srr,srr mfspr r11,SPRN_SRR0 ld r12,_NIP(r1) clrrdi r11,r11,2 clrrdi r12,r12,2 100: tdne r11,r12 EMIT_WARN_ENTRY 100b,__FILE__,__LINE__,(BUGFLAG_WARNING | BUGFLAG_ONCE) mfspr r11,SPRN_SRR1 ld r12,_MSR(r1) 100: tdne r11,r12 EMIT_WARN_ENTRY 100b,__FILE__,__LINE__,(BUGFLAG_WARNING | BUGFLAG_ONCE) .else mfspr r11,SPRN_HSRR0 ld r12,_NIP(r1) clrrdi r11,r11,2 clrrdi r12,r12,2 100: tdne r11,r12 EMIT_WARN_ENTRY 100b,__FILE__,__LINE__,(BUGFLAG_WARNING | BUGFLAG_ONCE) mfspr r11,SPRN_HSRR1 ld r12,_MSR(r1) 100: tdne r11,r12 EMIT_WARN_ENTRY 100b,__FILE__,__LINE__,(BUGFLAG_WARNING | BUGFLAG_ONCE) .endif #endif .endm #ifdef CONFIG_PPC_BOOK3S .macro system_call_vectored name trapnr .globl system_call_vectored_\name system_call_vectored_\name: _ASM_NOKPROBE_SYMBOL(system_call_vectored_\name) SCV_INTERRUPT_TO_KERNEL mr r10,r1 ld r1,PACAKSAVE(r13) std r10,0(r1) std r11,_NIP(r1) std r12,_MSR(r1) std r0,GPR0(r1) std r10,GPR1(r1) std r2,GPR2(r1) LOAD_PACA_TOC() mfcr r12 li r11,0 /* Save syscall parameters in r3-r8 */ SAVE_GPRS(3, 8, r1) /* Zero r9-r12, this should only be required when restoring all GPRs */ std r11,GPR9(r1) std r11,GPR10(r1) std r11,GPR11(r1) std r11,GPR12(r1) std r9,GPR13(r1) SAVE_NVGPRS(r1) std r11,_XER(r1) std r11,_LINK(r1) std r11,_CTR(r1) li r11,\trapnr std r11,_TRAP(r1) std r12,_CCR(r1) std r3,ORIG_GPR3(r1) /* Calling convention has r3 = regs, r4 = orig r0 */ addi r3,r1,STACK_INT_FRAME_REGS mr r4,r0 LOAD_REG_IMMEDIATE(r11, STACK_FRAME_REGS_MARKER) std r11,-16(r3) /* "regshere" marker */ BEGIN_FTR_SECTION HMT_MEDIUM END_FTR_SECTION_IFSET(CPU_FTR_HAS_PPR) /* * scv enters with MSR[EE]=1 and is immediately considered soft-masked. * The entry vector already sets PACAIRQSOFTMASK to IRQS_ALL_DISABLED, * and interrupts may be masked and pending already. * system_call_exception() will call trace_hardirqs_off() which means * interrupts could already have been blocked before trace_hardirqs_off, * but this is the best we can do. */ bl system_call_exception .Lsyscall_vectored_\name\()_exit: addi r4,r1,STACK_INT_FRAME_REGS li r5,1 /* scv */ bl syscall_exit_prepare std r1,PACA_EXIT_SAVE_R1(r13) /* save r1 for restart */ .Lsyscall_vectored_\name\()_rst_start: lbz r11,PACAIRQHAPPENED(r13) andi. r11,r11,(~PACA_IRQ_HARD_DIS)@l bne- syscall_vectored_\name\()_restart li r11,IRQS_ENABLED stb r11,PACAIRQSOFTMASK(r13) li r11,0 stb r11,PACAIRQHAPPENED(r13) # clear out possible HARD_DIS ld r2,_CCR(r1) ld r4,_NIP(r1) ld r5,_MSR(r1) BEGIN_FTR_SECTION stdcx. r0,0,r1 /* to clear the reservation */ END_FTR_SECTION_IFCLR(CPU_FTR_STCX_CHECKS_ADDRESS) BEGIN_FTR_SECTION HMT_MEDIUM_LOW END_FTR_SECTION_IFSET(CPU_FTR_HAS_PPR) cmpdi r3,0 bne .Lsyscall_vectored_\name\()_restore_regs /* rfscv returns with LR->NIA and CTR->MSR */ mtlr r4 mtctr r5 /* Could zero these as per ABI, but we may consider a stricter ABI * which preserves these if libc implementations can benefit, so * restore them for now until further measurement is done. */ REST_GPR(0, r1) REST_GPRS(4, 8, r1) /* Zero volatile regs that may contain sensitive kernel data */ ZEROIZE_GPRS(9, 12) mtspr SPRN_XER,r0 /* * We don't need to restore AMR on the way back to userspace for KUAP. * The value of AMR only matters while we're in the kernel. */ mtcr r2 REST_GPRS(2, 3, r1) REST_GPR(13, r1) REST_GPR(1, r1) RFSCV_TO_USER b . /* prevent speculative execution */ .Lsyscall_vectored_\name\()_restore_regs: mtspr SPRN_SRR0,r4 mtspr SPRN_SRR1,r5 ld r3,_CTR(r1) ld r4,_LINK(r1) ld r5,_XER(r1) REST_NVGPRS(r1) REST_GPR(0, r1) mtcr r2 mtctr r3 mtlr r4 mtspr SPRN_XER,r5 REST_GPRS(2, 13, r1) REST_GPR(1, r1) RFI_TO_USER .Lsyscall_vectored_\name\()_rst_end: syscall_vectored_\name\()_restart: _ASM_NOKPROBE_SYMBOL(syscall_vectored_\name\()_restart) GET_PACA(r13) ld r1,PACA_EXIT_SAVE_R1(r13) LOAD_PACA_TOC() ld r3,RESULT(r1) addi r4,r1,STACK_INT_FRAME_REGS li r11,IRQS_ALL_DISABLED stb r11,PACAIRQSOFTMASK(r13) bl syscall_exit_restart std r1,PACA_EXIT_SAVE_R1(r13) /* save r1 for restart */ b .Lsyscall_vectored_\name\()_rst_start 1: SOFT_MASK_TABLE(.Lsyscall_vectored_\name\()_rst_start, 1b) RESTART_TABLE(.Lsyscall_vectored_\name\()_rst_start, .Lsyscall_vectored_\name\()_rst_end, syscall_vectored_\name\()_restart) .endm system_call_vectored common 0x3000 /* * We instantiate another entry copy for the SIGILL variant, with TRAP=0x7ff0 * which is tested by system_call_exception when r0 is -1 (as set by vector * entry code). */ system_call_vectored sigill 0x7ff0 #endif /* CONFIG_PPC_BOOK3S */ .balign IFETCH_ALIGN_BYTES .globl system_call_common_real system_call_common_real: _ASM_NOKPROBE_SYMBOL(system_call_common_real) ld r10,PACAKMSR(r13) /* get MSR value for kernel */ mtmsrd r10 .balign IFETCH_ALIGN_BYTES .globl system_call_common system_call_common: _ASM_NOKPROBE_SYMBOL(system_call_common) mr r10,r1 ld r1,PACAKSAVE(r13) std r10,0(r1) std r11,_NIP(r1) std r12,_MSR(r1) std r0,GPR0(r1) std r10,GPR1(r1) std r2,GPR2(r1) #ifdef CONFIG_PPC_E500 START_BTB_FLUSH_SECTION BTB_FLUSH(r10) END_BTB_FLUSH_SECTION #endif LOAD_PACA_TOC() mfcr r12 li r11,0 /* Save syscall parameters in r3-r8 */ SAVE_GPRS(3, 8, r1) /* Zero r9-r12, this should only be required when restoring all GPRs */ std r11,GPR9(r1) std r11,GPR10(r1) std r11,GPR11(r1) std r11,GPR12(r1) std r9,GPR13(r1) SAVE_NVGPRS(r1) std r11,_XER(r1) std r11,_CTR(r1) mflr r10 /* * This clears CR0.SO (bit 28), which is the error indication on * return from this system call. */ rldimi r12,r11,28,(63-28) li r11,0xc00 std r10,_LINK(r1) std r11,_TRAP(r1) std r12,_CCR(r1) std r3,ORIG_GPR3(r1) /* Calling convention has r3 = regs, r4 = orig r0 */ addi r3,r1,STACK_INT_FRAME_REGS mr r4,r0 LOAD_REG_IMMEDIATE(r11, STACK_FRAME_REGS_MARKER) std r11,-16(r3) /* "regshere" marker */ #ifdef CONFIG_PPC_BOOK3S li r11,1 stb r11,PACASRR_VALID(r13) #endif /* * We always enter kernel from userspace with irq soft-mask enabled and * nothing pending. system_call_exception() will call * trace_hardirqs_off(). */ li r11,IRQS_ALL_DISABLED stb r11,PACAIRQSOFTMASK(r13) #ifdef CONFIG_PPC_BOOK3S li r12,-1 /* Set MSR_EE and MSR_RI */ mtmsrd r12,1 #else wrteei 1 #endif bl system_call_exception .Lsyscall_exit: addi r4,r1,STACK_INT_FRAME_REGS li r5,0 /* !scv */ bl syscall_exit_prepare std r1,PACA_EXIT_SAVE_R1(r13) /* save r1 for restart */ #ifdef CONFIG_PPC_BOOK3S .Lsyscall_rst_start: lbz r11,PACAIRQHAPPENED(r13) andi. r11,r11,(~PACA_IRQ_HARD_DIS)@l bne- syscall_restart #endif li r11,IRQS_ENABLED stb r11,PACAIRQSOFTMASK(r13) li r11,0 stb r11,PACAIRQHAPPENED(r13) # clear out possible HARD_DIS ld r2,_CCR(r1) ld r6,_LINK(r1) mtlr r6 #ifdef CONFIG_PPC_BOOK3S lbz r4,PACASRR_VALID(r13) cmpdi r4,0 bne 1f li r4,0 stb r4,PACASRR_VALID(r13) #endif ld r4,_NIP(r1) ld r5,_MSR(r1) mtspr SPRN_SRR0,r4 mtspr SPRN_SRR1,r5 1: DEBUG_SRR_VALID srr BEGIN_FTR_SECTION stdcx. r0,0,r1 /* to clear the reservation */ END_FTR_SECTION_IFCLR(CPU_FTR_STCX_CHECKS_ADDRESS) cmpdi r3,0 bne .Lsyscall_restore_regs /* Zero volatile regs that may contain sensitive kernel data */ ZEROIZE_GPR(0) ZEROIZE_GPRS(4, 12) mtctr r0 mtspr SPRN_XER,r0 .Lsyscall_restore_regs_cont: BEGIN_FTR_SECTION HMT_MEDIUM_LOW END_FTR_SECTION_IFSET(CPU_FTR_HAS_PPR) /* * We don't need to restore AMR on the way back to userspace for KUAP. * The value of AMR only matters while we're in the kernel. */ mtcr r2 REST_GPRS(2, 3, r1) REST_GPR(13, r1) REST_GPR(1, r1) RFI_TO_USER b . /* prevent speculative execution */ .Lsyscall_restore_regs: ld r3,_CTR(r1) ld r4,_XER(r1) REST_NVGPRS(r1) mtctr r3 mtspr SPRN_XER,r4 REST_GPR(0, r1) REST_GPRS(4, 12, r1) b .Lsyscall_restore_regs_cont .Lsyscall_rst_end: #ifdef CONFIG_PPC_BOOK3S syscall_restart: _ASM_NOKPROBE_SYMBOL(syscall_restart) GET_PACA(r13) ld r1,PACA_EXIT_SAVE_R1(r13) LOAD_PACA_TOC() ld r3,RESULT(r1) addi r4,r1,STACK_INT_FRAME_REGS li r11,IRQS_ALL_DISABLED stb r11,PACAIRQSOFTMASK(r13) bl syscall_exit_restart std r1,PACA_EXIT_SAVE_R1(r13) /* save r1 for restart */ b .Lsyscall_rst_start 1: SOFT_MASK_TABLE(.Lsyscall_rst_start, 1b) RESTART_TABLE(.Lsyscall_rst_start, .Lsyscall_rst_end, syscall_restart) #endif /* * If MSR EE/RI was never enabled, IRQs not reconciled, NVGPRs not * touched, no exit work created, then this can be used. */ .balign IFETCH_ALIGN_BYTES .globl fast_interrupt_return_srr fast_interrupt_return_srr: _ASM_NOKPROBE_SYMBOL(fast_interrupt_return_srr) kuap_check_amr r3, r4 ld r5,_MSR(r1) andi. r0,r5,MSR_PR #ifdef CONFIG_PPC_BOOK3S beq 1f kuap_user_restore r3, r4 b .Lfast_user_interrupt_return_srr 1: kuap_kernel_restore r3, r4 andi. r0,r5,MSR_RI li r3,0 /* 0 return value, no EMULATE_STACK_STORE */ bne+ .Lfast_kernel_interrupt_return_srr addi r3,r1,STACK_INT_FRAME_REGS bl unrecoverable_exception b . /* should not get here */ #else bne .Lfast_user_interrupt_return_srr b .Lfast_kernel_interrupt_return_srr #endif .macro interrupt_return_macro srr .balign IFETCH_ALIGN_BYTES .globl interrupt_return_\srr interrupt_return_\srr\(): _ASM_NOKPROBE_SYMBOL(interrupt_return_\srr\()) ld r4,_MSR(r1) andi. r0,r4,MSR_PR beq interrupt_return_\srr\()_kernel interrupt_return_\srr\()_user: /* make backtraces match the _kernel variant */ _ASM_NOKPROBE_SYMBOL(interrupt_return_\srr\()_user) addi r3,r1,STACK_INT_FRAME_REGS bl interrupt_exit_user_prepare cmpdi r3,0 bne- .Lrestore_nvgprs_\srr .Lrestore_nvgprs_\srr\()_cont: std r1,PACA_EXIT_SAVE_R1(r13) /* save r1 for restart */ #ifdef CONFIG_PPC_BOOK3S .Linterrupt_return_\srr\()_user_rst_start: lbz r11,PACAIRQHAPPENED(r13) andi. r11,r11,(~PACA_IRQ_HARD_DIS)@l bne- interrupt_return_\srr\()_user_restart #endif li r11,IRQS_ENABLED stb r11,PACAIRQSOFTMASK(r13) li r11,0 stb r11,PACAIRQHAPPENED(r13) # clear out possible HARD_DIS .Lfast_user_interrupt_return_\srr\(): #ifdef CONFIG_PPC_BOOK3S .ifc \srr,srr lbz r4,PACASRR_VALID(r13) .else lbz r4,PACAHSRR_VALID(r13) .endif cmpdi r4,0 li r4,0 bne 1f #endif ld r11,_NIP(r1) ld r12,_MSR(r1) .ifc \srr,srr mtspr SPRN_SRR0,r11 mtspr SPRN_SRR1,r12 1: #ifdef CONFIG_PPC_BOOK3S stb r4,PACASRR_VALID(r13) #endif .else mtspr SPRN_HSRR0,r11 mtspr SPRN_HSRR1,r12 1: #ifdef CONFIG_PPC_BOOK3S stb r4,PACAHSRR_VALID(r13) #endif .endif DEBUG_SRR_VALID \srr #ifdef CONFIG_PPC_IRQ_SOFT_MASK_DEBUG lbz r4,PACAIRQSOFTMASK(r13) tdnei r4,IRQS_ENABLED #endif BEGIN_FTR_SECTION ld r10,_PPR(r1) mtspr SPRN_PPR,r10 END_FTR_SECTION_IFSET(CPU_FTR_HAS_PPR) BEGIN_FTR_SECTION stdcx. r0,0,r1 /* to clear the reservation */ FTR_SECTION_ELSE ldarx r0,0,r1 ALT_FTR_SECTION_END_IFCLR(CPU_FTR_STCX_CHECKS_ADDRESS) ld r3,_CCR(r1) ld r4,_LINK(r1) ld r5,_CTR(r1) ld r6,_XER(r1) li r0,0 REST_GPRS(7, 13, r1) mtcr r3 mtlr r4 mtctr r5 mtspr SPRN_XER,r6 REST_GPRS(2, 6, r1) REST_GPR(0, r1) REST_GPR(1, r1) .ifc \srr,srr RFI_TO_USER .else HRFI_TO_USER .endif b . /* prevent speculative execution */ .Linterrupt_return_\srr\()_user_rst_end: .Lrestore_nvgprs_\srr\(): REST_NVGPRS(r1) b .Lrestore_nvgprs_\srr\()_cont #ifdef CONFIG_PPC_BOOK3S interrupt_return_\srr\()_user_restart: _ASM_NOKPROBE_SYMBOL(interrupt_return_\srr\()_user_restart) GET_PACA(r13) ld r1,PACA_EXIT_SAVE_R1(r13) LOAD_PACA_TOC() addi r3,r1,STACK_INT_FRAME_REGS li r11,IRQS_ALL_DISABLED stb r11,PACAIRQSOFTMASK(r13) bl interrupt_exit_user_restart std r1,PACA_EXIT_SAVE_R1(r13) /* save r1 for restart */ b .Linterrupt_return_\srr\()_user_rst_start 1: SOFT_MASK_TABLE(.Linterrupt_return_\srr\()_user_rst_start, 1b) RESTART_TABLE(.Linterrupt_return_\srr\()_user_rst_start, .Linterrupt_return_\srr\()_user_rst_end, interrupt_return_\srr\()_user_restart) #endif .balign IFETCH_ALIGN_BYTES interrupt_return_\srr\()_kernel: _ASM_NOKPROBE_SYMBOL(interrupt_return_\srr\()_kernel) addi r3,r1,STACK_INT_FRAME_REGS bl interrupt_exit_kernel_prepare std r1,PACA_EXIT_SAVE_R1(r13) /* save r1 for restart */ .Linterrupt_return_\srr\()_kernel_rst_start: ld r11,SOFTE(r1) cmpwi r11,IRQS_ENABLED stb r11,PACAIRQSOFTMASK(r13) beq .Linterrupt_return_\srr\()_soft_enabled /* * Returning to soft-disabled context. * Check if a MUST_HARD_MASK interrupt has become pending, in which * case we need to disable MSR[EE] in the return context. * * The MSR[EE] check catches among other things the short incoherency * in hard_irq_disable() between clearing MSR[EE] and setting * PACA_IRQ_HARD_DIS. */ ld r12,_MSR(r1) andi. r10,r12,MSR_EE beq .Lfast_kernel_interrupt_return_\srr\() // EE already disabled lbz r11,PACAIRQHAPPENED(r13) andi. r10,r11,PACA_IRQ_MUST_HARD_MASK bne 1f // HARD_MASK is pending // No HARD_MASK pending, clear possible HARD_DIS set by interrupt andi. r11,r11,(~PACA_IRQ_HARD_DIS)@l stb r11,PACAIRQHAPPENED(r13) b .Lfast_kernel_interrupt_return_\srr\() 1: /* Must clear MSR_EE from _MSR */ #ifdef CONFIG_PPC_BOOK3S li r10,0 /* Clear valid before changing _MSR */ .ifc \srr,srr stb r10,PACASRR_VALID(r13) .else stb r10,PACAHSRR_VALID(r13) .endif #endif xori r12,r12,MSR_EE std r12,_MSR(r1) b .Lfast_kernel_interrupt_return_\srr\() .Linterrupt_return_\srr\()_soft_enabled: /* * In the soft-enabled case, need to double-check that we have no * pending interrupts that might have come in before we reached the * restart section of code, and restart the exit so those can be * handled. * * If there are none, it is be possible that the interrupt still * has PACA_IRQ_HARD_DIS set, which needs to be cleared for the * interrupted context. This clear will not clobber a new pending * interrupt coming in, because we're in the restart section, so * such would return to the restart location. */ #ifdef CONFIG_PPC_BOOK3S lbz r11,PACAIRQHAPPENED(r13) andi. r11,r11,(~PACA_IRQ_HARD_DIS)@l bne- interrupt_return_\srr\()_kernel_restart #endif li r11,0 stb r11,PACAIRQHAPPENED(r13) // clear the possible HARD_DIS .Lfast_kernel_interrupt_return_\srr\(): cmpdi cr1,r3,0 #ifdef CONFIG_PPC_BOOK3S .ifc \srr,srr lbz r4,PACASRR_VALID(r13) .else lbz r4,PACAHSRR_VALID(r13) .endif cmpdi r4,0 li r4,0 bne 1f #endif ld r11,_NIP(r1) ld r12,_MSR(r1) .ifc \srr,srr mtspr SPRN_SRR0,r11 mtspr SPRN_SRR1,r12 1: #ifdef CONFIG_PPC_BOOK3S stb r4,PACASRR_VALID(r13) #endif .else mtspr SPRN_HSRR0,r11 mtspr SPRN_HSRR1,r12 1: #ifdef CONFIG_PPC_BOOK3S stb r4,PACAHSRR_VALID(r13) #endif .endif DEBUG_SRR_VALID \srr BEGIN_FTR_SECTION stdcx. r0,0,r1 /* to clear the reservation */ FTR_SECTION_ELSE ldarx r0,0,r1 ALT_FTR_SECTION_END_IFCLR(CPU_FTR_STCX_CHECKS_ADDRESS) ld r3,_LINK(r1) ld r4,_CTR(r1) ld r5,_XER(r1) ld r6,_CCR(r1) li r0,0 REST_GPRS(7, 12, r1) mtlr r3 mtctr r4 mtspr SPRN_XER,r5 /* * Leaving a stale STACK_FRAME_REGS_MARKER on the stack can confuse * the reliable stack unwinder later on. Clear it. */ std r0,STACK_FRAME_OVERHEAD-16(r1) REST_GPRS(2, 5, r1) bne- cr1,1f /* emulate stack store */ mtcr r6 REST_GPR(6, r1) REST_GPR(0, r1) REST_GPR(1, r1) .ifc \srr,srr RFI_TO_KERNEL .else HRFI_TO_KERNEL .endif b . /* prevent speculative execution */ 1: /* * Emulate stack store with update. New r1 value was already calculated * and updated in our interrupt regs by emulate_loadstore, but we can't * store the previous value of r1 to the stack before re-loading our * registers from it, otherwise they could be clobbered. Use * PACA_EXGEN as temporary storage to hold the store data, as * interrupts are disabled here so it won't be clobbered. */ mtcr r6 std r9,PACA_EXGEN+0(r13) addi r9,r1,INT_FRAME_SIZE /* get original r1 */ REST_GPR(6, r1) REST_GPR(0, r1) REST_GPR(1, r1) std r9,0(r1) /* perform store component of stdu */ ld r9,PACA_EXGEN+0(r13) .ifc \srr,srr RFI_TO_KERNEL .else HRFI_TO_KERNEL .endif b . /* prevent speculative execution */ .Linterrupt_return_\srr\()_kernel_rst_end: #ifdef CONFIG_PPC_BOOK3S interrupt_return_\srr\()_kernel_restart: _ASM_NOKPROBE_SYMBOL(interrupt_return_\srr\()_kernel_restart) GET_PACA(r13) ld r1,PACA_EXIT_SAVE_R1(r13) LOAD_PACA_TOC() addi r3,r1,STACK_INT_FRAME_REGS li r11,IRQS_ALL_DISABLED stb r11,PACAIRQSOFTMASK(r13) bl interrupt_exit_kernel_restart std r1,PACA_EXIT_SAVE_R1(r13) /* save r1 for restart */ b .Linterrupt_return_\srr\()_kernel_rst_start 1: SOFT_MASK_TABLE(.Linterrupt_return_\srr\()_kernel_rst_start, 1b) RESTART_TABLE(.Linterrupt_return_\srr\()_kernel_rst_start, .Linterrupt_return_\srr\()_kernel_rst_end, interrupt_return_\srr\()_kernel_restart) #endif .endm interrupt_return_macro srr #ifdef CONFIG_PPC_BOOK3S interrupt_return_macro hsrr .globl __end_soft_masked __end_soft_masked: DEFINE_FIXED_SYMBOL(__end_soft_masked, text) #endif /* CONFIG_PPC_BOOK3S */ #ifdef CONFIG_PPC_BOOK3S _GLOBAL(ret_from_fork_scv) bl schedule_tail REST_NVGPRS(r1) li r3,0 /* fork() return value */ b .Lsyscall_vectored_common_exit #endif _GLOBAL(ret_from_fork) bl schedule_tail REST_NVGPRS(r1) li r3,0 /* fork() return value */ b .Lsyscall_exit _GLOBAL(ret_from_kernel_thread) bl schedule_tail REST_NVGPRS(r1) mtctr r14 mr r3,r15 #ifdef CONFIG_PPC64_ELF_ABI_V2 mr r12,r14 #endif bctrl li r3,0 b .Lsyscall_exit