mirror of
https://github.com/edk2-porting/linux-next.git
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206b1c6012
It used to clear a3, so that signal handling on return to userland would've passed zero r0 to do_work_pending(), preventing the syscall restart logics from triggering. It had been pointless all along, since we only go there after successful do_execve(). Which does clear regs->r0 on alpha, preventing the syscall restart logics just fine, no extra help needed. Good thing, that, since back in 2012 do_work_pending() has lost the second argument, shifting the registers used to pass that thing from a3 to a2. Commit that had done that adjusted the entry.S code accordingly, but missed that one. As the result, we were left with useless insn in ret_from_kernel_thread and confusing comment to go with it. Get rid of both... Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
858 lines
18 KiB
ArmAsm
858 lines
18 KiB
ArmAsm
/* SPDX-License-Identifier: GPL-2.0 */
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/*
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* arch/alpha/kernel/entry.S
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*
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* Kernel entry-points.
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*/
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#include <asm/asm-offsets.h>
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#include <asm/thread_info.h>
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#include <asm/pal.h>
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#include <asm/errno.h>
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#include <asm/unistd.h>
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.text
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.set noat
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.cfi_sections .debug_frame
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/* Stack offsets. */
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#define SP_OFF 184
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#define SWITCH_STACK_SIZE 320
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.macro CFI_START_OSF_FRAME func
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.align 4
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.globl \func
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.type \func,@function
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\func:
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.cfi_startproc simple
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.cfi_return_column 64
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.cfi_def_cfa $sp, 48
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.cfi_rel_offset 64, 8
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.cfi_rel_offset $gp, 16
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.cfi_rel_offset $16, 24
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.cfi_rel_offset $17, 32
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.cfi_rel_offset $18, 40
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.endm
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.macro CFI_END_OSF_FRAME func
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.cfi_endproc
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.size \func, . - \func
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.endm
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/*
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* This defines the normal kernel pt-regs layout.
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*
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* regs 9-15 preserved by C code
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* regs 16-18 saved by PAL-code
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* regs 29-30 saved and set up by PAL-code
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* JRP - Save regs 16-18 in a special area of the stack, so that
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* the palcode-provided values are available to the signal handler.
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*/
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.macro SAVE_ALL
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subq $sp, SP_OFF, $sp
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.cfi_adjust_cfa_offset SP_OFF
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stq $0, 0($sp)
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stq $1, 8($sp)
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stq $2, 16($sp)
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stq $3, 24($sp)
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stq $4, 32($sp)
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stq $28, 144($sp)
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.cfi_rel_offset $0, 0
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.cfi_rel_offset $1, 8
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.cfi_rel_offset $2, 16
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.cfi_rel_offset $3, 24
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.cfi_rel_offset $4, 32
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.cfi_rel_offset $28, 144
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lda $2, alpha_mv
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stq $5, 40($sp)
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stq $6, 48($sp)
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stq $7, 56($sp)
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stq $8, 64($sp)
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stq $19, 72($sp)
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stq $20, 80($sp)
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stq $21, 88($sp)
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ldq $2, HAE_CACHE($2)
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stq $22, 96($sp)
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stq $23, 104($sp)
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stq $24, 112($sp)
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stq $25, 120($sp)
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stq $26, 128($sp)
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stq $27, 136($sp)
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stq $2, 152($sp)
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stq $16, 160($sp)
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stq $17, 168($sp)
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stq $18, 176($sp)
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.cfi_rel_offset $5, 40
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.cfi_rel_offset $6, 48
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.cfi_rel_offset $7, 56
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.cfi_rel_offset $8, 64
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.cfi_rel_offset $19, 72
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.cfi_rel_offset $20, 80
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.cfi_rel_offset $21, 88
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.cfi_rel_offset $22, 96
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.cfi_rel_offset $23, 104
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.cfi_rel_offset $24, 112
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.cfi_rel_offset $25, 120
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.cfi_rel_offset $26, 128
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.cfi_rel_offset $27, 136
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.endm
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.macro RESTORE_ALL
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lda $19, alpha_mv
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ldq $0, 0($sp)
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ldq $1, 8($sp)
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ldq $2, 16($sp)
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ldq $3, 24($sp)
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ldq $21, 152($sp)
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ldq $20, HAE_CACHE($19)
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ldq $4, 32($sp)
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ldq $5, 40($sp)
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ldq $6, 48($sp)
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ldq $7, 56($sp)
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subq $20, $21, $20
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ldq $8, 64($sp)
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beq $20, 99f
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ldq $20, HAE_REG($19)
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stq $21, HAE_CACHE($19)
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stq $21, 0($20)
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99: ldq $19, 72($sp)
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ldq $20, 80($sp)
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ldq $21, 88($sp)
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ldq $22, 96($sp)
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ldq $23, 104($sp)
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ldq $24, 112($sp)
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ldq $25, 120($sp)
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ldq $26, 128($sp)
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ldq $27, 136($sp)
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ldq $28, 144($sp)
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addq $sp, SP_OFF, $sp
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.cfi_restore $0
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.cfi_restore $1
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.cfi_restore $2
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.cfi_restore $3
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.cfi_restore $4
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.cfi_restore $5
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.cfi_restore $6
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.cfi_restore $7
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.cfi_restore $8
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.cfi_restore $19
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.cfi_restore $20
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.cfi_restore $21
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.cfi_restore $22
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.cfi_restore $23
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.cfi_restore $24
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.cfi_restore $25
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.cfi_restore $26
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.cfi_restore $27
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.cfi_restore $28
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.cfi_adjust_cfa_offset -SP_OFF
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.endm
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.macro DO_SWITCH_STACK
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bsr $1, do_switch_stack
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.cfi_adjust_cfa_offset SWITCH_STACK_SIZE
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.cfi_rel_offset $9, 0
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.cfi_rel_offset $10, 8
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.cfi_rel_offset $11, 16
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.cfi_rel_offset $12, 24
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.cfi_rel_offset $13, 32
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.cfi_rel_offset $14, 40
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.cfi_rel_offset $15, 48
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/* We don't really care about the FP registers for debugging. */
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.endm
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.macro UNDO_SWITCH_STACK
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bsr $1, undo_switch_stack
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.cfi_restore $9
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.cfi_restore $10
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.cfi_restore $11
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.cfi_restore $12
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.cfi_restore $13
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.cfi_restore $14
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.cfi_restore $15
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.cfi_adjust_cfa_offset -SWITCH_STACK_SIZE
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.endm
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/*
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* Non-syscall kernel entry points.
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*/
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CFI_START_OSF_FRAME entInt
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SAVE_ALL
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lda $8, 0x3fff
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lda $26, ret_from_sys_call
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bic $sp, $8, $8
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mov $sp, $19
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jsr $31, do_entInt
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CFI_END_OSF_FRAME entInt
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CFI_START_OSF_FRAME entArith
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SAVE_ALL
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lda $8, 0x3fff
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lda $26, ret_from_sys_call
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bic $sp, $8, $8
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mov $sp, $18
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jsr $31, do_entArith
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CFI_END_OSF_FRAME entArith
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CFI_START_OSF_FRAME entMM
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SAVE_ALL
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/* save $9 - $15 so the inline exception code can manipulate them. */
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subq $sp, 56, $sp
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.cfi_adjust_cfa_offset 56
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stq $9, 0($sp)
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stq $10, 8($sp)
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stq $11, 16($sp)
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stq $12, 24($sp)
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stq $13, 32($sp)
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stq $14, 40($sp)
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stq $15, 48($sp)
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.cfi_rel_offset $9, 0
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.cfi_rel_offset $10, 8
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.cfi_rel_offset $11, 16
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.cfi_rel_offset $12, 24
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.cfi_rel_offset $13, 32
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.cfi_rel_offset $14, 40
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.cfi_rel_offset $15, 48
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addq $sp, 56, $19
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/* handle the fault */
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lda $8, 0x3fff
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bic $sp, $8, $8
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jsr $26, do_page_fault
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/* reload the registers after the exception code played. */
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ldq $9, 0($sp)
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ldq $10, 8($sp)
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ldq $11, 16($sp)
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ldq $12, 24($sp)
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ldq $13, 32($sp)
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ldq $14, 40($sp)
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ldq $15, 48($sp)
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addq $sp, 56, $sp
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.cfi_restore $9
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.cfi_restore $10
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.cfi_restore $11
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.cfi_restore $12
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.cfi_restore $13
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.cfi_restore $14
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.cfi_restore $15
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.cfi_adjust_cfa_offset -56
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/* finish up the syscall as normal. */
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br ret_from_sys_call
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CFI_END_OSF_FRAME entMM
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CFI_START_OSF_FRAME entIF
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SAVE_ALL
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lda $8, 0x3fff
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lda $26, ret_from_sys_call
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bic $sp, $8, $8
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mov $sp, $17
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jsr $31, do_entIF
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CFI_END_OSF_FRAME entIF
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CFI_START_OSF_FRAME entUna
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lda $sp, -256($sp)
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.cfi_adjust_cfa_offset 256
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stq $0, 0($sp)
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.cfi_rel_offset $0, 0
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.cfi_remember_state
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ldq $0, 256($sp) /* get PS */
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stq $1, 8($sp)
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stq $2, 16($sp)
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stq $3, 24($sp)
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and $0, 8, $0 /* user mode? */
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stq $4, 32($sp)
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bne $0, entUnaUser /* yup -> do user-level unaligned fault */
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stq $5, 40($sp)
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stq $6, 48($sp)
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stq $7, 56($sp)
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stq $8, 64($sp)
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stq $9, 72($sp)
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stq $10, 80($sp)
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stq $11, 88($sp)
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stq $12, 96($sp)
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stq $13, 104($sp)
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stq $14, 112($sp)
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stq $15, 120($sp)
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/* 16-18 PAL-saved */
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stq $19, 152($sp)
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stq $20, 160($sp)
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stq $21, 168($sp)
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stq $22, 176($sp)
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stq $23, 184($sp)
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stq $24, 192($sp)
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stq $25, 200($sp)
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stq $26, 208($sp)
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stq $27, 216($sp)
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stq $28, 224($sp)
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mov $sp, $19
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stq $gp, 232($sp)
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.cfi_rel_offset $1, 1*8
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.cfi_rel_offset $2, 2*8
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.cfi_rel_offset $3, 3*8
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.cfi_rel_offset $4, 4*8
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.cfi_rel_offset $5, 5*8
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.cfi_rel_offset $6, 6*8
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.cfi_rel_offset $7, 7*8
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.cfi_rel_offset $8, 8*8
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.cfi_rel_offset $9, 9*8
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.cfi_rel_offset $10, 10*8
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.cfi_rel_offset $11, 11*8
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.cfi_rel_offset $12, 12*8
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.cfi_rel_offset $13, 13*8
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.cfi_rel_offset $14, 14*8
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.cfi_rel_offset $15, 15*8
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.cfi_rel_offset $19, 19*8
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.cfi_rel_offset $20, 20*8
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.cfi_rel_offset $21, 21*8
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.cfi_rel_offset $22, 22*8
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.cfi_rel_offset $23, 23*8
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.cfi_rel_offset $24, 24*8
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.cfi_rel_offset $25, 25*8
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.cfi_rel_offset $26, 26*8
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.cfi_rel_offset $27, 27*8
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.cfi_rel_offset $28, 28*8
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.cfi_rel_offset $29, 29*8
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lda $8, 0x3fff
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stq $31, 248($sp)
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bic $sp, $8, $8
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jsr $26, do_entUna
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ldq $0, 0($sp)
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ldq $1, 8($sp)
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ldq $2, 16($sp)
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ldq $3, 24($sp)
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ldq $4, 32($sp)
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ldq $5, 40($sp)
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ldq $6, 48($sp)
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ldq $7, 56($sp)
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ldq $8, 64($sp)
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ldq $9, 72($sp)
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ldq $10, 80($sp)
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ldq $11, 88($sp)
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ldq $12, 96($sp)
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ldq $13, 104($sp)
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ldq $14, 112($sp)
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ldq $15, 120($sp)
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/* 16-18 PAL-saved */
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ldq $19, 152($sp)
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ldq $20, 160($sp)
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ldq $21, 168($sp)
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ldq $22, 176($sp)
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ldq $23, 184($sp)
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ldq $24, 192($sp)
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ldq $25, 200($sp)
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ldq $26, 208($sp)
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ldq $27, 216($sp)
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ldq $28, 224($sp)
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ldq $gp, 232($sp)
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lda $sp, 256($sp)
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.cfi_restore $1
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.cfi_restore $2
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.cfi_restore $3
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.cfi_restore $4
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.cfi_restore $5
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.cfi_restore $6
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.cfi_restore $7
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.cfi_restore $8
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.cfi_restore $9
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.cfi_restore $10
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.cfi_restore $11
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.cfi_restore $12
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.cfi_restore $13
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.cfi_restore $14
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.cfi_restore $15
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.cfi_restore $19
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.cfi_restore $20
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.cfi_restore $21
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.cfi_restore $22
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.cfi_restore $23
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.cfi_restore $24
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.cfi_restore $25
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.cfi_restore $26
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.cfi_restore $27
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.cfi_restore $28
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.cfi_restore $29
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.cfi_adjust_cfa_offset -256
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call_pal PAL_rti
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.align 4
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entUnaUser:
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.cfi_restore_state
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ldq $0, 0($sp) /* restore original $0 */
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lda $sp, 256($sp) /* pop entUna's stack frame */
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.cfi_restore $0
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.cfi_adjust_cfa_offset -256
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SAVE_ALL /* setup normal kernel stack */
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lda $sp, -56($sp)
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.cfi_adjust_cfa_offset 56
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stq $9, 0($sp)
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stq $10, 8($sp)
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stq $11, 16($sp)
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stq $12, 24($sp)
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stq $13, 32($sp)
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stq $14, 40($sp)
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stq $15, 48($sp)
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.cfi_rel_offset $9, 0
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.cfi_rel_offset $10, 8
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.cfi_rel_offset $11, 16
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.cfi_rel_offset $12, 24
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.cfi_rel_offset $13, 32
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.cfi_rel_offset $14, 40
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.cfi_rel_offset $15, 48
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lda $8, 0x3fff
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addq $sp, 56, $19
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bic $sp, $8, $8
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jsr $26, do_entUnaUser
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ldq $9, 0($sp)
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ldq $10, 8($sp)
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ldq $11, 16($sp)
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ldq $12, 24($sp)
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ldq $13, 32($sp)
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ldq $14, 40($sp)
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ldq $15, 48($sp)
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lda $sp, 56($sp)
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.cfi_restore $9
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.cfi_restore $10
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.cfi_restore $11
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.cfi_restore $12
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.cfi_restore $13
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.cfi_restore $14
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.cfi_restore $15
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.cfi_adjust_cfa_offset -56
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br ret_from_sys_call
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CFI_END_OSF_FRAME entUna
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CFI_START_OSF_FRAME entDbg
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SAVE_ALL
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lda $8, 0x3fff
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lda $26, ret_from_sys_call
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bic $sp, $8, $8
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mov $sp, $16
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jsr $31, do_entDbg
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CFI_END_OSF_FRAME entDbg
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/*
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* The system call entry point is special. Most importantly, it looks
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* like a function call to userspace as far as clobbered registers. We
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* do preserve the argument registers (for syscall restarts) and $26
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* (for leaf syscall functions).
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*
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* So much for theory. We don't take advantage of this yet.
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*
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* Note that a0-a2 are not saved by PALcode as with the other entry points.
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*/
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.align 4
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.globl entSys
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.type entSys, @function
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.cfi_startproc simple
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.cfi_return_column 64
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.cfi_def_cfa $sp, 48
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.cfi_rel_offset 64, 8
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.cfi_rel_offset $gp, 16
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entSys:
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SAVE_ALL
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lda $8, 0x3fff
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bic $sp, $8, $8
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lda $4, NR_SYSCALLS($31)
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stq $16, SP_OFF+24($sp)
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lda $5, sys_call_table
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lda $27, sys_ni_syscall
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cmpult $0, $4, $4
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ldl $3, TI_FLAGS($8)
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stq $17, SP_OFF+32($sp)
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s8addq $0, $5, $5
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stq $18, SP_OFF+40($sp)
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.cfi_rel_offset $16, SP_OFF+24
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.cfi_rel_offset $17, SP_OFF+32
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.cfi_rel_offset $18, SP_OFF+40
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#ifdef CONFIG_AUDITSYSCALL
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lda $6, _TIF_SYSCALL_TRACE | _TIF_SYSCALL_AUDIT
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and $3, $6, $3
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#endif
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bne $3, strace
|
||
beq $4, 1f
|
||
ldq $27, 0($5)
|
||
1: jsr $26, ($27), alpha_ni_syscall
|
||
ldgp $gp, 0($26)
|
||
blt $0, $syscall_error /* the call failed */
|
||
stq $0, 0($sp)
|
||
stq $31, 72($sp) /* a3=0 => no error */
|
||
|
||
.align 4
|
||
.globl ret_from_sys_call
|
||
ret_from_sys_call:
|
||
cmovne $26, 0, $18 /* $18 = 0 => non-restartable */
|
||
ldq $0, SP_OFF($sp)
|
||
and $0, 8, $0
|
||
beq $0, ret_to_kernel
|
||
ret_to_user:
|
||
/* Make sure need_resched and sigpending don't change between
|
||
sampling and the rti. */
|
||
lda $16, 7
|
||
call_pal PAL_swpipl
|
||
ldl $17, TI_FLAGS($8)
|
||
and $17, _TIF_WORK_MASK, $2
|
||
bne $2, work_pending
|
||
restore_all:
|
||
.cfi_remember_state
|
||
RESTORE_ALL
|
||
call_pal PAL_rti
|
||
|
||
ret_to_kernel:
|
||
.cfi_restore_state
|
||
lda $16, 7
|
||
call_pal PAL_swpipl
|
||
br restore_all
|
||
|
||
.align 3
|
||
$syscall_error:
|
||
/*
|
||
* Some system calls (e.g., ptrace) can return arbitrary
|
||
* values which might normally be mistaken as error numbers.
|
||
* Those functions must zero $0 (v0) directly in the stack
|
||
* frame to indicate that a negative return value wasn't an
|
||
* error number..
|
||
*/
|
||
ldq $18, 0($sp) /* old syscall nr (zero if success) */
|
||
beq $18, $ret_success
|
||
|
||
ldq $19, 72($sp) /* .. and this a3 */
|
||
subq $31, $0, $0 /* with error in v0 */
|
||
addq $31, 1, $1 /* set a3 for errno return */
|
||
stq $0, 0($sp)
|
||
mov $31, $26 /* tell "ret_from_sys_call" we can restart */
|
||
stq $1, 72($sp) /* a3 for return */
|
||
br ret_from_sys_call
|
||
|
||
$ret_success:
|
||
stq $0, 0($sp)
|
||
stq $31, 72($sp) /* a3=0 => no error */
|
||
br ret_from_sys_call
|
||
|
||
/*
|
||
* Do all cleanup when returning from all interrupts and system calls.
|
||
*
|
||
* Arguments:
|
||
* $8: current.
|
||
* $17: TI_FLAGS.
|
||
* $18: The old syscall number, or zero if this is not a return
|
||
* from a syscall that errored and is possibly restartable.
|
||
* $19: The old a3 value
|
||
*/
|
||
|
||
.align 4
|
||
.type work_pending, @function
|
||
work_pending:
|
||
and $17, _TIF_NOTIFY_RESUME | _TIF_SIGPENDING, $2
|
||
bne $2, $work_notifysig
|
||
|
||
$work_resched:
|
||
/*
|
||
* We can get here only if we returned from syscall without SIGPENDING
|
||
* or got through work_notifysig already. Either case means no syscall
|
||
* restarts for us, so let $18 and $19 burn.
|
||
*/
|
||
jsr $26, schedule
|
||
mov 0, $18
|
||
br ret_to_user
|
||
|
||
$work_notifysig:
|
||
mov $sp, $16
|
||
DO_SWITCH_STACK
|
||
jsr $26, do_work_pending
|
||
UNDO_SWITCH_STACK
|
||
br restore_all
|
||
|
||
/*
|
||
* PTRACE syscall handler
|
||
*/
|
||
|
||
.align 4
|
||
.type strace, @function
|
||
strace:
|
||
/* set up signal stack, call syscall_trace */
|
||
DO_SWITCH_STACK
|
||
jsr $26, syscall_trace_enter /* returns the syscall number */
|
||
UNDO_SWITCH_STACK
|
||
|
||
/* get the arguments back.. */
|
||
ldq $16, SP_OFF+24($sp)
|
||
ldq $17, SP_OFF+32($sp)
|
||
ldq $18, SP_OFF+40($sp)
|
||
ldq $19, 72($sp)
|
||
ldq $20, 80($sp)
|
||
ldq $21, 88($sp)
|
||
|
||
/* get the system call pointer.. */
|
||
lda $1, NR_SYSCALLS($31)
|
||
lda $2, sys_call_table
|
||
lda $27, alpha_ni_syscall
|
||
cmpult $0, $1, $1
|
||
s8addq $0, $2, $2
|
||
beq $1, 1f
|
||
ldq $27, 0($2)
|
||
1: jsr $26, ($27), sys_gettimeofday
|
||
ret_from_straced:
|
||
ldgp $gp, 0($26)
|
||
|
||
/* check return.. */
|
||
blt $0, $strace_error /* the call failed */
|
||
stq $31, 72($sp) /* a3=0 => no error */
|
||
$strace_success:
|
||
stq $0, 0($sp) /* save return value */
|
||
|
||
DO_SWITCH_STACK
|
||
jsr $26, syscall_trace_leave
|
||
UNDO_SWITCH_STACK
|
||
br $31, ret_from_sys_call
|
||
|
||
.align 3
|
||
$strace_error:
|
||
ldq $18, 0($sp) /* old syscall nr (zero if success) */
|
||
beq $18, $strace_success
|
||
ldq $19, 72($sp) /* .. and this a3 */
|
||
|
||
subq $31, $0, $0 /* with error in v0 */
|
||
addq $31, 1, $1 /* set a3 for errno return */
|
||
stq $0, 0($sp)
|
||
stq $1, 72($sp) /* a3 for return */
|
||
|
||
DO_SWITCH_STACK
|
||
mov $18, $9 /* save old syscall number */
|
||
mov $19, $10 /* save old a3 */
|
||
jsr $26, syscall_trace_leave
|
||
mov $9, $18
|
||
mov $10, $19
|
||
UNDO_SWITCH_STACK
|
||
|
||
mov $31, $26 /* tell "ret_from_sys_call" we can restart */
|
||
br ret_from_sys_call
|
||
CFI_END_OSF_FRAME entSys
|
||
|
||
/*
|
||
* Save and restore the switch stack -- aka the balance of the user context.
|
||
*/
|
||
|
||
.align 4
|
||
.type do_switch_stack, @function
|
||
.cfi_startproc simple
|
||
.cfi_return_column 64
|
||
.cfi_def_cfa $sp, 0
|
||
.cfi_register 64, $1
|
||
do_switch_stack:
|
||
lda $sp, -SWITCH_STACK_SIZE($sp)
|
||
.cfi_adjust_cfa_offset SWITCH_STACK_SIZE
|
||
stq $9, 0($sp)
|
||
stq $10, 8($sp)
|
||
stq $11, 16($sp)
|
||
stq $12, 24($sp)
|
||
stq $13, 32($sp)
|
||
stq $14, 40($sp)
|
||
stq $15, 48($sp)
|
||
stq $26, 56($sp)
|
||
stt $f0, 64($sp)
|
||
stt $f1, 72($sp)
|
||
stt $f2, 80($sp)
|
||
stt $f3, 88($sp)
|
||
stt $f4, 96($sp)
|
||
stt $f5, 104($sp)
|
||
stt $f6, 112($sp)
|
||
stt $f7, 120($sp)
|
||
stt $f8, 128($sp)
|
||
stt $f9, 136($sp)
|
||
stt $f10, 144($sp)
|
||
stt $f11, 152($sp)
|
||
stt $f12, 160($sp)
|
||
stt $f13, 168($sp)
|
||
stt $f14, 176($sp)
|
||
stt $f15, 184($sp)
|
||
stt $f16, 192($sp)
|
||
stt $f17, 200($sp)
|
||
stt $f18, 208($sp)
|
||
stt $f19, 216($sp)
|
||
stt $f20, 224($sp)
|
||
stt $f21, 232($sp)
|
||
stt $f22, 240($sp)
|
||
stt $f23, 248($sp)
|
||
stt $f24, 256($sp)
|
||
stt $f25, 264($sp)
|
||
stt $f26, 272($sp)
|
||
stt $f27, 280($sp)
|
||
mf_fpcr $f0 # get fpcr
|
||
stt $f28, 288($sp)
|
||
stt $f29, 296($sp)
|
||
stt $f30, 304($sp)
|
||
stt $f0, 312($sp) # save fpcr in slot of $f31
|
||
ldt $f0, 64($sp) # dont let "do_switch_stack" change fp state.
|
||
ret $31, ($1), 1
|
||
.cfi_endproc
|
||
.size do_switch_stack, .-do_switch_stack
|
||
|
||
.align 4
|
||
.type undo_switch_stack, @function
|
||
.cfi_startproc simple
|
||
.cfi_def_cfa $sp, 0
|
||
.cfi_register 64, $1
|
||
undo_switch_stack:
|
||
ldq $9, 0($sp)
|
||
ldq $10, 8($sp)
|
||
ldq $11, 16($sp)
|
||
ldq $12, 24($sp)
|
||
ldq $13, 32($sp)
|
||
ldq $14, 40($sp)
|
||
ldq $15, 48($sp)
|
||
ldq $26, 56($sp)
|
||
ldt $f30, 312($sp) # get saved fpcr
|
||
ldt $f0, 64($sp)
|
||
ldt $f1, 72($sp)
|
||
ldt $f2, 80($sp)
|
||
ldt $f3, 88($sp)
|
||
mt_fpcr $f30 # install saved fpcr
|
||
ldt $f4, 96($sp)
|
||
ldt $f5, 104($sp)
|
||
ldt $f6, 112($sp)
|
||
ldt $f7, 120($sp)
|
||
ldt $f8, 128($sp)
|
||
ldt $f9, 136($sp)
|
||
ldt $f10, 144($sp)
|
||
ldt $f11, 152($sp)
|
||
ldt $f12, 160($sp)
|
||
ldt $f13, 168($sp)
|
||
ldt $f14, 176($sp)
|
||
ldt $f15, 184($sp)
|
||
ldt $f16, 192($sp)
|
||
ldt $f17, 200($sp)
|
||
ldt $f18, 208($sp)
|
||
ldt $f19, 216($sp)
|
||
ldt $f20, 224($sp)
|
||
ldt $f21, 232($sp)
|
||
ldt $f22, 240($sp)
|
||
ldt $f23, 248($sp)
|
||
ldt $f24, 256($sp)
|
||
ldt $f25, 264($sp)
|
||
ldt $f26, 272($sp)
|
||
ldt $f27, 280($sp)
|
||
ldt $f28, 288($sp)
|
||
ldt $f29, 296($sp)
|
||
ldt $f30, 304($sp)
|
||
lda $sp, SWITCH_STACK_SIZE($sp)
|
||
ret $31, ($1), 1
|
||
.cfi_endproc
|
||
.size undo_switch_stack, .-undo_switch_stack
|
||
|
||
/*
|
||
* The meat of the context switch code.
|
||
*/
|
||
|
||
.align 4
|
||
.globl alpha_switch_to
|
||
.type alpha_switch_to, @function
|
||
.cfi_startproc
|
||
alpha_switch_to:
|
||
DO_SWITCH_STACK
|
||
call_pal PAL_swpctx
|
||
lda $8, 0x3fff
|
||
UNDO_SWITCH_STACK
|
||
bic $sp, $8, $8
|
||
mov $17, $0
|
||
ret
|
||
.cfi_endproc
|
||
.size alpha_switch_to, .-alpha_switch_to
|
||
|
||
/*
|
||
* New processes begin life here.
|
||
*/
|
||
|
||
.globl ret_from_fork
|
||
.align 4
|
||
.ent ret_from_fork
|
||
ret_from_fork:
|
||
lda $26, ret_from_sys_call
|
||
mov $17, $16
|
||
jmp $31, schedule_tail
|
||
.end ret_from_fork
|
||
|
||
/*
|
||
* ... and new kernel threads - here
|
||
*/
|
||
.align 4
|
||
.globl ret_from_kernel_thread
|
||
.ent ret_from_kernel_thread
|
||
ret_from_kernel_thread:
|
||
mov $17, $16
|
||
jsr $26, schedule_tail
|
||
mov $9, $27
|
||
mov $10, $16
|
||
jsr $26, ($9)
|
||
br $31, ret_to_user
|
||
.end ret_from_kernel_thread
|
||
|
||
|
||
/*
|
||
* Special system calls. Most of these are special in that they either
|
||
* have to play switch_stack games or in some way use the pt_regs struct.
|
||
*/
|
||
|
||
.macro fork_like name
|
||
.align 4
|
||
.globl alpha_\name
|
||
.ent alpha_\name
|
||
alpha_\name:
|
||
.prologue 0
|
||
bsr $1, do_switch_stack
|
||
jsr $26, sys_\name
|
||
ldq $26, 56($sp)
|
||
lda $sp, SWITCH_STACK_SIZE($sp)
|
||
ret
|
||
.end alpha_\name
|
||
.endm
|
||
|
||
fork_like fork
|
||
fork_like vfork
|
||
fork_like clone
|
||
|
||
.align 4
|
||
.globl sys_sigreturn
|
||
.ent sys_sigreturn
|
||
sys_sigreturn:
|
||
.prologue 0
|
||
lda $9, ret_from_straced
|
||
cmpult $26, $9, $9
|
||
lda $sp, -SWITCH_STACK_SIZE($sp)
|
||
jsr $26, do_sigreturn
|
||
bne $9, 1f
|
||
jsr $26, syscall_trace_leave
|
||
1: br $1, undo_switch_stack
|
||
br ret_from_sys_call
|
||
.end sys_sigreturn
|
||
|
||
.align 4
|
||
.globl sys_rt_sigreturn
|
||
.ent sys_rt_sigreturn
|
||
sys_rt_sigreturn:
|
||
.prologue 0
|
||
lda $9, ret_from_straced
|
||
cmpult $26, $9, $9
|
||
lda $sp, -SWITCH_STACK_SIZE($sp)
|
||
jsr $26, do_rt_sigreturn
|
||
bne $9, 1f
|
||
jsr $26, syscall_trace_leave
|
||
1: br $1, undo_switch_stack
|
||
br ret_from_sys_call
|
||
.end sys_rt_sigreturn
|
||
|
||
.align 4
|
||
.globl alpha_ni_syscall
|
||
.ent alpha_ni_syscall
|
||
alpha_ni_syscall:
|
||
.prologue 0
|
||
/* Special because it also implements overflow handling via
|
||
syscall number 0. And if you recall, zero is a special
|
||
trigger for "not an error". Store large non-zero there. */
|
||
lda $0, -ENOSYS
|
||
unop
|
||
stq $0, 0($sp)
|
||
ret
|
||
.end alpha_ni_syscall
|