diff options
Diffstat (limited to 'arch/parisc/kernel/vdso64/sigtramp.S')
| -rw-r--r-- | arch/parisc/kernel/vdso64/sigtramp.S | 166 |
1 files changed, 166 insertions, 0 deletions
diff --git a/arch/parisc/kernel/vdso64/sigtramp.S b/arch/parisc/kernel/vdso64/sigtramp.S new file mode 100644 index 0000000000..66a6d2b241 --- /dev/null +++ b/arch/parisc/kernel/vdso64/sigtramp.S @@ -0,0 +1,166 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * Signal trampolines for 64 bit processes. + * + * Copyright (C) 2006 Randolph Chung <tausq@debian.org> + * Copyright (C) 2018-2022 Helge Deller <deller@gmx.de> + * Copyright (C) 2022 John David Anglin <dave.anglin@bell.net> + */ +#include <asm/unistd.h> +#include <linux/linkage.h> +#include <generated/asm-offsets.h> + + .text + +/* Gdb expects the trampoline is on the stack and the pc is offset from + a 64-byte boundary by 0, 4 or 5 instructions. Since the vdso trampoline + is not on the stack, we need a new variant with different offsets and + data to tell gdb where to find the signal context on the stack. + + Here we put the offset to the context data at the start of the trampoline + region and offset the first trampoline by 2 instructions. Please do + not change the trampoline as the code in gdb depends on the following + instruction sequence exactly. + */ + .align 64 + .word SIGFRAME_CONTEXT_REGS + +/* The nop here is a hack. The dwarf2 unwind routines subtract 1 from + the return address to get an address in the middle of the presumed + call instruction. Since we don't have a call here, we artifically + extend the range covered by the unwind info by adding a nop before + the real start. + */ + nop + + .globl __kernel_sigtramp_rt + .type __kernel_sigtramp_rt, @function +__kernel_sigtramp_rt: + .proc + .callinfo FRAME=ASM_SIGFRAME_SIZE,CALLS,SAVE_RP + .entry + +.Lsigrt_start = . - 4 +0: ldi 0, %r25 /* (in_syscall=0) */ + ldi __NR_rt_sigreturn, %r20 + ble 0x100(%sr2, %r0) + nop + +1: ldi 1, %r25 /* (in_syscall=1) */ + ldi __NR_rt_sigreturn, %r20 + ble 0x100(%sr2, %r0) + nop +.Lsigrt_end: + .exit + .procend + .size __kernel_sigtramp_rt,.-__kernel_sigtramp_rt + + .section .eh_frame,"a",@progbits + +/* This is where the mcontext_t struct can be found on the stack. */ +#define PTREGS SIGFRAME_CONTEXT_REGS /* 64-bit process offset is -720 */ + +/* Register REGNO can be found at offset OFS of the mcontext_t structure. */ + .macro rsave regno,ofs + .byte 0x05 /* DW_CFA_offset_extended */ + .uleb128 \regno; /* regno */ + .uleb128 \ofs /* factored offset */ + .endm + +.Lcie: + .long .Lcie_end - .Lcie_start +.Lcie_start: + .long 0 /* CIE ID */ + .byte 1 /* Version number */ + .stringz "zRS" /* NUL-terminated augmentation string */ + .uleb128 4 /* Code alignment factor */ + .sleb128 8 /* Data alignment factor */ + .byte 61 /* Return address register column, iaoq[0] */ + .uleb128 1 /* Augmentation value length */ + .byte 0x1b /* DW_EH_PE_pcrel | DW_EH_PE_sdata4. */ + .byte 0x0f /* DW_CFA_def_cfa_expresion */ + .uleb128 9f - 1f /* length */ +1: + .byte 0x8e /* DW_OP_breg30 */ + .sleb128 PTREGS +9: + .balign 8 +.Lcie_end: + + .long .Lfde0_end - .Lfde0_start +.Lfde0_start: + .long .Lfde0_start - .Lcie /* CIE pointer. */ + .long .Lsigrt_start - . /* PC start, length */ + .long .Lsigrt_end - .Lsigrt_start + .uleb128 0 /* Augmentation */ + + /* General registers */ + rsave 1, 2 + rsave 2, 3 + rsave 3, 4 + rsave 4, 5 + rsave 5, 6 + rsave 6, 7 + rsave 7, 8 + rsave 8, 9 + rsave 9, 10 + rsave 10, 11 + rsave 11, 12 + rsave 12, 13 + rsave 13, 14 + rsave 14, 15 + rsave 15, 16 + rsave 16, 17 + rsave 17, 18 + rsave 18, 19 + rsave 19, 20 + rsave 20, 21 + rsave 21, 22 + rsave 22, 23 + rsave 23, 24 + rsave 24, 25 + rsave 25, 26 + rsave 26, 27 + rsave 27, 28 + rsave 28, 29 + rsave 29, 30 + rsave 30, 31 + rsave 31, 32 + + /* Floating-point registers */ + rsave 32, 36 + rsave 33, 37 + rsave 34, 38 + rsave 35, 39 + rsave 36, 40 + rsave 37, 41 + rsave 38, 42 + rsave 39, 43 + rsave 40, 44 + rsave 41, 45 + rsave 42, 46 + rsave 43, 47 + rsave 44, 48 + rsave 45, 49 + rsave 46, 50 + rsave 47, 51 + rsave 48, 52 + rsave 49, 53 + rsave 50, 54 + rsave 51, 55 + rsave 52, 56 + rsave 53, 57 + rsave 54, 58 + rsave 55, 59 + rsave 56, 60 + rsave 57, 61 + rsave 58, 62 + rsave 59, 63 + + /* SAR register */ + rsave 60, 67 + + /* iaoq[0] return address register */ + rsave 61, 65 + .balign 8 +.Lfde0_end: |