diff options
Diffstat (limited to 'arch/powerpc/kernel/vdso/sigtramp64.S')
| -rw-r--r-- | arch/powerpc/kernel/vdso/sigtramp64.S | 313 |
1 files changed, 313 insertions, 0 deletions
diff --git a/arch/powerpc/kernel/vdso/sigtramp64.S b/arch/powerpc/kernel/vdso/sigtramp64.S new file mode 100644 index 000000000000..2d4067561293 --- /dev/null +++ b/arch/powerpc/kernel/vdso/sigtramp64.S @@ -0,0 +1,313 @@ +/* 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: |