| /* SPDX-License-Identifier: GPL-2.0-or-later */ |
| /* |
| * Signal trampoline for 64 bits processes in a ppc64 kernel for |
| * use in the vDSO |
| * |
| * Copyright (C) 2004 Benjamin Herrenschmuidt (benh@kernel.crashing.org), IBM Corp. |
| * Copyright (C) 2004 Alan Modra (amodra@au.ibm.com)), IBM Corp. |
| */ |
| #include <asm/cache.h> /* IFETCH_ALIGN_BYTES */ |
| #include <asm/processor.h> |
| #include <asm/ppc_asm.h> |
| #include <asm/unistd.h> |
| #include <asm/vdso.h> |
| #include <asm/ptrace.h> /* XXX for __SIGNAL_FRAMESIZE */ |
| |
| .text |
| |
| /* |
| * __kernel_start_sigtramp_rt64 and __kernel_sigtramp_rt64 together |
| * are one function split in two parts. The kernel jumps to the former |
| * and the signal handler indirectly (by blr) returns to the latter. |
| * __kernel_sigtramp_rt64 needs to point to the return address so |
| * glibc can correctly identify the trampoline stack frame. |
| */ |
| .balign 8 |
| .balign IFETCH_ALIGN_BYTES |
| V_FUNCTION_BEGIN(__kernel_start_sigtramp_rt64) |
| .Lsigrt_start: |
| bctrl /* call the handler */ |
| V_FUNCTION_END(__kernel_start_sigtramp_rt64) |
| V_FUNCTION_BEGIN(__kernel_sigtramp_rt64) |
| addi r1, r1, __SIGNAL_FRAMESIZE |
| li r0,__NR_rt_sigreturn |
| sc |
| .Lsigrt_end: |
| V_FUNCTION_END(__kernel_sigtramp_rt64) |
| /* The .balign 8 above and the following zeros mimic the old stack |
| trampoline layout. The last magic value is the ucontext pointer, |
| chosen in such a way that older libgcc unwind code returns a zero |
| for a sigcontext pointer. */ |
| .long 0,0,0 |
| .quad 0,-21*8 |
| |
| /* Register r1 can be found at offset 8 of a pt_regs structure. |
| A pointer to the pt_regs is stored in memory at the old sp plus PTREGS. */ |
| #define cfa_save \ |
| .byte 0x0f; /* DW_CFA_def_cfa_expression */ \ |
| .uleb128 9f - 1f; /* length */ \ |
| 1: \ |
| .byte 0x71; .sleb128 PTREGS; /* DW_OP_breg1 */ \ |
| .byte 0x06; /* DW_OP_deref */ \ |
| .byte 0x23; .uleb128 RSIZE; /* DW_OP_plus_uconst */ \ |
| .byte 0x06; /* DW_OP_deref */ \ |
| 9: |
| |
| /* Register REGNO can be found at offset OFS of a pt_regs structure. |
| A pointer to the pt_regs is stored in memory at the old sp plus PTREGS. */ |
| #define rsave(regno, ofs) \ |
| .byte 0x10; /* DW_CFA_expression */ \ |
| .uleb128 regno; /* regno */ \ |
| .uleb128 9f - 1f; /* length */ \ |
| 1: \ |
| .byte 0x71; .sleb128 PTREGS; /* DW_OP_breg1 */ \ |
| .byte 0x06; /* DW_OP_deref */ \ |
| .ifne ofs; \ |
| .byte 0x23; .uleb128 ofs; /* DW_OP_plus_uconst */ \ |
| .endif; \ |
| 9: |
| |
| /* If msr bit 1<<25 is set, then VMX register REGNO is at offset REGNO*16 |
| of the VMX reg struct. A pointer to the VMX reg struct is at VREGS in |
| the pt_regs struct. This macro is for REGNO == 0, and contains |
| 'subroutines' that the other macros jump to. */ |
| #define vsave_msr0(regno) \ |
| .byte 0x10; /* DW_CFA_expression */ \ |
| .uleb128 regno + 77; /* regno */ \ |
| .uleb128 9f - 1f; /* length */ \ |
| 1: \ |
| .byte 0x30 + regno; /* DW_OP_lit0 */ \ |
| 2: \ |
| .byte 0x40; /* DW_OP_lit16 */ \ |
| .byte 0x1e; /* DW_OP_mul */ \ |
| 3: \ |
| .byte 0x71; .sleb128 PTREGS; /* DW_OP_breg1 */ \ |
| .byte 0x06; /* DW_OP_deref */ \ |
| .byte 0x12; /* DW_OP_dup */ \ |
| .byte 0x23; /* DW_OP_plus_uconst */ \ |
| .uleb128 33*RSIZE; /* msr offset */ \ |
| .byte 0x06; /* DW_OP_deref */ \ |
| .byte 0x0c; .long 1 << 25; /* DW_OP_const4u */ \ |
| .byte 0x1a; /* DW_OP_and */ \ |
| .byte 0x12; /* DW_OP_dup, ret 0 if bra taken */ \ |
| .byte 0x30; /* DW_OP_lit0 */ \ |
| .byte 0x29; /* DW_OP_eq */ \ |
| .byte 0x28; .short 0x7fff; /* DW_OP_bra to end */ \ |
| .byte 0x13; /* DW_OP_drop, pop the 0 */ \ |
| .byte 0x23; .uleb128 VREGS; /* DW_OP_plus_uconst */ \ |
| .byte 0x06; /* DW_OP_deref */ \ |
| .byte 0x22; /* DW_OP_plus */ \ |
| .byte 0x2f; .short 0x7fff; /* DW_OP_skip to end */ \ |
| 9: |
| |
| /* If msr bit 1<<25 is set, then VMX register REGNO is at offset REGNO*16 |
| of the VMX reg struct. REGNO is 1 thru 31. */ |
| #define vsave_msr1(regno) \ |
| .byte 0x10; /* DW_CFA_expression */ \ |
| .uleb128 regno + 77; /* regno */ \ |
| .uleb128 9f - 1f; /* length */ \ |
| 1: \ |
| .byte 0x30 + regno; /* DW_OP_lit n */ \ |
| .byte 0x2f; .short 2b - 9f; /* DW_OP_skip */ \ |
| 9: |
| |
| /* If msr bit 1<<25 is set, then VMX register REGNO is at offset OFS of |
| the VMX save block. */ |
| #define vsave_msr2(regno, ofs) \ |
| .byte 0x10; /* DW_CFA_expression */ \ |
| .uleb128 regno + 77; /* regno */ \ |
| .uleb128 9f - 1f; /* length */ \ |
| 1: \ |
| .byte 0x0a; .short ofs; /* DW_OP_const2u */ \ |
| .byte 0x2f; .short 3b - 9f; /* DW_OP_skip */ \ |
| 9: |
| |
| /* VMX register REGNO is at offset OFS of the VMX save area. */ |
| #define vsave(regno, ofs) \ |
| .byte 0x10; /* DW_CFA_expression */ \ |
| .uleb128 regno + 77; /* regno */ \ |
| .uleb128 9f - 1f; /* length */ \ |
| 1: \ |
| .byte 0x71; .sleb128 PTREGS; /* DW_OP_breg1 */ \ |
| .byte 0x06; /* DW_OP_deref */ \ |
| .byte 0x23; .uleb128 VREGS; /* DW_OP_plus_uconst */ \ |
| .byte 0x06; /* DW_OP_deref */ \ |
| .byte 0x23; .uleb128 ofs; /* DW_OP_plus_uconst */ \ |
| 9: |
| |
| /* This is where the pt_regs pointer can be found on the stack. */ |
| #define PTREGS 128+168+56 |
| |
| /* Size of regs. */ |
| #define RSIZE 8 |
| |
| /* Size of CR reg in DWARF unwind info. */ |
| #define CRSIZE 4 |
| |
| /* Offset of CR reg within a full word. */ |
| #ifdef __LITTLE_ENDIAN__ |
| #define CROFF 0 |
| #else |
| #define CROFF (RSIZE - CRSIZE) |
| #endif |
| |
| /* This is the offset of the VMX reg pointer. */ |
| #define VREGS 48*RSIZE+33*8 |
| |
| /* Describe where general purpose regs are saved. */ |
| #define EH_FRAME_GEN \ |
| cfa_save; \ |
| rsave ( 0, 0*RSIZE); \ |
| rsave ( 2, 2*RSIZE); \ |
| rsave ( 3, 3*RSIZE); \ |
| rsave ( 4, 4*RSIZE); \ |
| rsave ( 5, 5*RSIZE); \ |
| rsave ( 6, 6*RSIZE); \ |
| rsave ( 7, 7*RSIZE); \ |
| rsave ( 8, 8*RSIZE); \ |
| rsave ( 9, 9*RSIZE); \ |
| rsave (10, 10*RSIZE); \ |
| rsave (11, 11*RSIZE); \ |
| rsave (12, 12*RSIZE); \ |
| rsave (13, 13*RSIZE); \ |
| rsave (14, 14*RSIZE); \ |
| rsave (15, 15*RSIZE); \ |
| rsave (16, 16*RSIZE); \ |
| rsave (17, 17*RSIZE); \ |
| rsave (18, 18*RSIZE); \ |
| rsave (19, 19*RSIZE); \ |
| rsave (20, 20*RSIZE); \ |
| rsave (21, 21*RSIZE); \ |
| rsave (22, 22*RSIZE); \ |
| rsave (23, 23*RSIZE); \ |
| rsave (24, 24*RSIZE); \ |
| rsave (25, 25*RSIZE); \ |
| rsave (26, 26*RSIZE); \ |
| rsave (27, 27*RSIZE); \ |
| rsave (28, 28*RSIZE); \ |
| rsave (29, 29*RSIZE); \ |
| rsave (30, 30*RSIZE); \ |
| rsave (31, 31*RSIZE); \ |
| rsave (67, 32*RSIZE); /* ap, used as temp for nip */ \ |
| rsave (65, 36*RSIZE); /* lr */ \ |
| rsave (68, 38*RSIZE + CROFF); /* cr fields */ \ |
| rsave (69, 38*RSIZE + CROFF); \ |
| rsave (70, 38*RSIZE + CROFF); \ |
| rsave (71, 38*RSIZE + CROFF); \ |
| rsave (72, 38*RSIZE + CROFF); \ |
| rsave (73, 38*RSIZE + CROFF); \ |
| rsave (74, 38*RSIZE + CROFF); \ |
| rsave (75, 38*RSIZE + CROFF) |
| |
| /* Describe where the FP regs are saved. */ |
| #define EH_FRAME_FP \ |
| rsave (32, 48*RSIZE + 0*8); \ |
| rsave (33, 48*RSIZE + 1*8); \ |
| rsave (34, 48*RSIZE + 2*8); \ |
| rsave (35, 48*RSIZE + 3*8); \ |
| rsave (36, 48*RSIZE + 4*8); \ |
| rsave (37, 48*RSIZE + 5*8); \ |
| rsave (38, 48*RSIZE + 6*8); \ |
| rsave (39, 48*RSIZE + 7*8); \ |
| rsave (40, 48*RSIZE + 8*8); \ |
| rsave (41, 48*RSIZE + 9*8); \ |
| rsave (42, 48*RSIZE + 10*8); \ |
| rsave (43, 48*RSIZE + 11*8); \ |
| rsave (44, 48*RSIZE + 12*8); \ |
| rsave (45, 48*RSIZE + 13*8); \ |
| rsave (46, 48*RSIZE + 14*8); \ |
| rsave (47, 48*RSIZE + 15*8); \ |
| rsave (48, 48*RSIZE + 16*8); \ |
| rsave (49, 48*RSIZE + 17*8); \ |
| rsave (50, 48*RSIZE + 18*8); \ |
| rsave (51, 48*RSIZE + 19*8); \ |
| rsave (52, 48*RSIZE + 20*8); \ |
| rsave (53, 48*RSIZE + 21*8); \ |
| rsave (54, 48*RSIZE + 22*8); \ |
| rsave (55, 48*RSIZE + 23*8); \ |
| rsave (56, 48*RSIZE + 24*8); \ |
| rsave (57, 48*RSIZE + 25*8); \ |
| rsave (58, 48*RSIZE + 26*8); \ |
| rsave (59, 48*RSIZE + 27*8); \ |
| rsave (60, 48*RSIZE + 28*8); \ |
| rsave (61, 48*RSIZE + 29*8); \ |
| rsave (62, 48*RSIZE + 30*8); \ |
| rsave (63, 48*RSIZE + 31*8) |
| |
| /* Describe where the VMX regs are saved. */ |
| #ifdef CONFIG_ALTIVEC |
| #define EH_FRAME_VMX \ |
| vsave_msr0 ( 0); \ |
| vsave_msr1 ( 1); \ |
| vsave_msr1 ( 2); \ |
| vsave_msr1 ( 3); \ |
| vsave_msr1 ( 4); \ |
| vsave_msr1 ( 5); \ |
| vsave_msr1 ( 6); \ |
| vsave_msr1 ( 7); \ |
| vsave_msr1 ( 8); \ |
| vsave_msr1 ( 9); \ |
| vsave_msr1 (10); \ |
| vsave_msr1 (11); \ |
| vsave_msr1 (12); \ |
| vsave_msr1 (13); \ |
| vsave_msr1 (14); \ |
| vsave_msr1 (15); \ |
| vsave_msr1 (16); \ |
| vsave_msr1 (17); \ |
| vsave_msr1 (18); \ |
| vsave_msr1 (19); \ |
| vsave_msr1 (20); \ |
| vsave_msr1 (21); \ |
| vsave_msr1 (22); \ |
| vsave_msr1 (23); \ |
| vsave_msr1 (24); \ |
| vsave_msr1 (25); \ |
| vsave_msr1 (26); \ |
| vsave_msr1 (27); \ |
| vsave_msr1 (28); \ |
| vsave_msr1 (29); \ |
| vsave_msr1 (30); \ |
| vsave_msr1 (31); \ |
| vsave_msr2 (33, 32*16+12); \ |
| vsave (32, 33*16) |
| #else |
| #define EH_FRAME_VMX |
| #endif |
| |
| .section .eh_frame,"a",@progbits |
| .Lcie: |
| .long .Lcie_end - .Lcie_start |
| .Lcie_start: |
| .long 0 /* CIE ID */ |
| .byte 1 /* Version number */ |
| .string "zRS" /* NUL-terminated augmentation string */ |
| .uleb128 4 /* Code alignment factor */ |
| .sleb128 -8 /* Data alignment factor */ |
| .byte 67 /* Return address register column, ap */ |
| .uleb128 1 /* Augmentation value length */ |
| .byte 0x14 /* DW_EH_PE_pcrel | DW_EH_PE_udata8. */ |
| .byte 0x0c,1,0 /* DW_CFA_def_cfa: r1 ofs 0 */ |
| .balign 8 |
| .Lcie_end: |
| |
| .long .Lfde0_end - .Lfde0_start |
| .Lfde0_start: |
| .long .Lfde0_start - .Lcie /* CIE pointer. */ |
| .quad .Lsigrt_start - . /* PC start, length */ |
| .quad .Lsigrt_end - .Lsigrt_start |
| .uleb128 0 /* Augmentation */ |
| EH_FRAME_GEN |
| EH_FRAME_FP |
| EH_FRAME_VMX |
| # Do we really need to describe the frame at this point? ie. will |
| # we ever have some call chain that returns somewhere past the addi? |
| # I don't think so, since gcc doesn't support async signals. |
| # .byte 0x41 /* DW_CFA_advance_loc 1*4 */ |
| #undef PTREGS |
| #define PTREGS 168+56 |
| # EH_FRAME_GEN |
| # EH_FRAME_FP |
| # EH_FRAME_VMX |
| .balign 8 |
| .Lfde0_end: |
