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linux_dsm_epyc7002/arch/alpha/kernel/entry.S
Al Viro 206b1c6012 alpha: get rid of pointless insn in ret_from_kernel_thread 
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>
2018-03-28 08:58:27 -04:00

858 lines
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/* SPDX-License-Identifier: GPL-2.0 */
/*
* arch/alpha/kernel/entry.S
*
* Kernel entry-points.
*/
#include <asm/asm-offsets.h>
#include <asm/thread_info.h>
#include <asm/pal.h>
#include <asm/errno.h>
#include <asm/unistd.h>
.text
.set noat
.cfi_sections .debug_frame
/* Stack offsets. */
#define SP_OFF 184
#define SWITCH_STACK_SIZE 320
.macro CFI_START_OSF_FRAME func
.align 4
.globl \func
.type \func,@function
\func:
.cfi_startproc simple
.cfi_return_column 64
.cfi_def_cfa $sp, 48
.cfi_rel_offset 64, 8
.cfi_rel_offset $gp, 16
.cfi_rel_offset $16, 24
.cfi_rel_offset $17, 32
.cfi_rel_offset $18, 40
.endm
.macro CFI_END_OSF_FRAME func
.cfi_endproc
.size \func, . - \func
.endm
/*
* This defines the normal kernel pt-regs layout.
*
* regs 9-15 preserved by C code
* regs 16-18 saved by PAL-code
* regs 29-30 saved and set up by PAL-code
* JRP - Save regs 16-18 in a special area of the stack, so that
* the palcode-provided values are available to the signal handler.
*/
.macro SAVE_ALL
subq $sp, SP_OFF, $sp
.cfi_adjust_cfa_offset SP_OFF
stq $0, 0($sp)
stq $1, 8($sp)
stq $2, 16($sp)
stq $3, 24($sp)
stq $4, 32($sp)
stq $28, 144($sp)
.cfi_rel_offset $0, 0
.cfi_rel_offset $1, 8
.cfi_rel_offset $2, 16
.cfi_rel_offset $3, 24
.cfi_rel_offset $4, 32
.cfi_rel_offset $28, 144
lda $2, alpha_mv
stq $5, 40($sp)
stq $6, 48($sp)
stq $7, 56($sp)
stq $8, 64($sp)
stq $19, 72($sp)
stq $20, 80($sp)
stq $21, 88($sp)
ldq $2, HAE_CACHE($2)
stq $22, 96($sp)
stq $23, 104($sp)
stq $24, 112($sp)
stq $25, 120($sp)
stq $26, 128($sp)
stq $27, 136($sp)
stq $2, 152($sp)
stq $16, 160($sp)
stq $17, 168($sp)
stq $18, 176($sp)
.cfi_rel_offset $5, 40
.cfi_rel_offset $6, 48
.cfi_rel_offset $7, 56
.cfi_rel_offset $8, 64
.cfi_rel_offset $19, 72
.cfi_rel_offset $20, 80
.cfi_rel_offset $21, 88
.cfi_rel_offset $22, 96
.cfi_rel_offset $23, 104
.cfi_rel_offset $24, 112
.cfi_rel_offset $25, 120
.cfi_rel_offset $26, 128
.cfi_rel_offset $27, 136
.endm
.macro RESTORE_ALL
lda $19, alpha_mv
ldq $0, 0($sp)
ldq $1, 8($sp)
ldq $2, 16($sp)
ldq $3, 24($sp)
ldq $21, 152($sp)
ldq $20, HAE_CACHE($19)
ldq $4, 32($sp)
ldq $5, 40($sp)
ldq $6, 48($sp)
ldq $7, 56($sp)
subq $20, $21, $20
ldq $8, 64($sp)
beq $20, 99f
ldq $20, HAE_REG($19)
stq $21, HAE_CACHE($19)
stq $21, 0($20)
99: ldq $19, 72($sp)
ldq $20, 80($sp)
ldq $21, 88($sp)
ldq $22, 96($sp)
ldq $23, 104($sp)
ldq $24, 112($sp)
ldq $25, 120($sp)
ldq $26, 128($sp)
ldq $27, 136($sp)
ldq $28, 144($sp)
addq $sp, SP_OFF, $sp
.cfi_restore $0
.cfi_restore $1
.cfi_restore $2
.cfi_restore $3
.cfi_restore $4
.cfi_restore $5
.cfi_restore $6
.cfi_restore $7
.cfi_restore $8
.cfi_restore $19
.cfi_restore $20
.cfi_restore $21
.cfi_restore $22
.cfi_restore $23
.cfi_restore $24
.cfi_restore $25
.cfi_restore $26
.cfi_restore $27
.cfi_restore $28
.cfi_adjust_cfa_offset -SP_OFF
.endm
.macro DO_SWITCH_STACK
bsr $1, do_switch_stack
.cfi_adjust_cfa_offset SWITCH_STACK_SIZE
.cfi_rel_offset $9, 0
.cfi_rel_offset $10, 8
.cfi_rel_offset $11, 16
.cfi_rel_offset $12, 24
.cfi_rel_offset $13, 32
.cfi_rel_offset $14, 40
.cfi_rel_offset $15, 48
/* We don't really care about the FP registers for debugging. */
.endm
.macro UNDO_SWITCH_STACK
bsr $1, undo_switch_stack
.cfi_restore $9
.cfi_restore $10
.cfi_restore $11
.cfi_restore $12
.cfi_restore $13
.cfi_restore $14
.cfi_restore $15
.cfi_adjust_cfa_offset -SWITCH_STACK_SIZE
.endm
/*
* Non-syscall kernel entry points.
*/
CFI_START_OSF_FRAME entInt
SAVE_ALL
lda $8, 0x3fff
lda $26, ret_from_sys_call
bic $sp, $8, $8
mov $sp, $19
jsr $31, do_entInt
CFI_END_OSF_FRAME entInt
CFI_START_OSF_FRAME entArith
SAVE_ALL
lda $8, 0x3fff
lda $26, ret_from_sys_call
bic $sp, $8, $8
mov $sp, $18
jsr $31, do_entArith
CFI_END_OSF_FRAME entArith
CFI_START_OSF_FRAME entMM
SAVE_ALL
/* save $9 - $15 so the inline exception code can manipulate them. */
subq $sp, 56, $sp
.cfi_adjust_cfa_offset 56
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)
.cfi_rel_offset $9, 0
.cfi_rel_offset $10, 8
.cfi_rel_offset $11, 16
.cfi_rel_offset $12, 24
.cfi_rel_offset $13, 32
.cfi_rel_offset $14, 40
.cfi_rel_offset $15, 48
addq $sp, 56, $19
/* handle the fault */
lda $8, 0x3fff
bic $sp, $8, $8
jsr $26, do_page_fault
/* reload the registers after the exception code played. */
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)
addq $sp, 56, $sp
.cfi_restore $9
.cfi_restore $10
.cfi_restore $11
.cfi_restore $12
.cfi_restore $13
.cfi_restore $14
.cfi_restore $15
.cfi_adjust_cfa_offset -56
/* finish up the syscall as normal. */
br ret_from_sys_call
CFI_END_OSF_FRAME entMM
CFI_START_OSF_FRAME entIF
SAVE_ALL
lda $8, 0x3fff
lda $26, ret_from_sys_call
bic $sp, $8, $8
mov $sp, $17
jsr $31, do_entIF
CFI_END_OSF_FRAME entIF
CFI_START_OSF_FRAME entUna
lda $sp, -256($sp)
.cfi_adjust_cfa_offset 256
stq $0, 0($sp)
.cfi_rel_offset $0, 0
.cfi_remember_state
ldq $0, 256($sp) /* get PS */
stq $1, 8($sp)
stq $2, 16($sp)
stq $3, 24($sp)
and $0, 8, $0 /* user mode? */
stq $4, 32($sp)
bne $0, entUnaUser /* yup -> do user-level unaligned fault */
stq $5, 40($sp)
stq $6, 48($sp)
stq $7, 56($sp)
stq $8, 64($sp)
stq $9, 72($sp)
stq $10, 80($sp)
stq $11, 88($sp)
stq $12, 96($sp)
stq $13, 104($sp)
stq $14, 112($sp)
stq $15, 120($sp)
/* 16-18 PAL-saved */
stq $19, 152($sp)
stq $20, 160($sp)
stq $21, 168($sp)
stq $22, 176($sp)
stq $23, 184($sp)
stq $24, 192($sp)
stq $25, 200($sp)
stq $26, 208($sp)
stq $27, 216($sp)
stq $28, 224($sp)
mov $sp, $19
stq $gp, 232($sp)
.cfi_rel_offset $1, 1*8
.cfi_rel_offset $2, 2*8
.cfi_rel_offset $3, 3*8
.cfi_rel_offset $4, 4*8
.cfi_rel_offset $5, 5*8
.cfi_rel_offset $6, 6*8
.cfi_rel_offset $7, 7*8
.cfi_rel_offset $8, 8*8
.cfi_rel_offset $9, 9*8
.cfi_rel_offset $10, 10*8
.cfi_rel_offset $11, 11*8
.cfi_rel_offset $12, 12*8
.cfi_rel_offset $13, 13*8
.cfi_rel_offset $14, 14*8
.cfi_rel_offset $15, 15*8
.cfi_rel_offset $19, 19*8
.cfi_rel_offset $20, 20*8
.cfi_rel_offset $21, 21*8
.cfi_rel_offset $22, 22*8
.cfi_rel_offset $23, 23*8
.cfi_rel_offset $24, 24*8
.cfi_rel_offset $25, 25*8
.cfi_rel_offset $26, 26*8
.cfi_rel_offset $27, 27*8
.cfi_rel_offset $28, 28*8
.cfi_rel_offset $29, 29*8
lda $8, 0x3fff
stq $31, 248($sp)
bic $sp, $8, $8
jsr $26, do_entUna
ldq $0, 0($sp)
ldq $1, 8($sp)
ldq $2, 16($sp)
ldq $3, 24($sp)
ldq $4, 32($sp)
ldq $5, 40($sp)
ldq $6, 48($sp)
ldq $7, 56($sp)
ldq $8, 64($sp)
ldq $9, 72($sp)
ldq $10, 80($sp)
ldq $11, 88($sp)
ldq $12, 96($sp)
ldq $13, 104($sp)
ldq $14, 112($sp)
ldq $15, 120($sp)
/* 16-18 PAL-saved */
ldq $19, 152($sp)
ldq $20, 160($sp)
ldq $21, 168($sp)
ldq $22, 176($sp)
ldq $23, 184($sp)
ldq $24, 192($sp)
ldq $25, 200($sp)
ldq $26, 208($sp)
ldq $27, 216($sp)
ldq $28, 224($sp)
ldq $gp, 232($sp)
lda $sp, 256($sp)
.cfi_restore $1
.cfi_restore $2
.cfi_restore $3
.cfi_restore $4
.cfi_restore $5
.cfi_restore $6
.cfi_restore $7
.cfi_restore $8
.cfi_restore $9
.cfi_restore $10
.cfi_restore $11
.cfi_restore $12
.cfi_restore $13
.cfi_restore $14
.cfi_restore $15
.cfi_restore $19
.cfi_restore $20
.cfi_restore $21
.cfi_restore $22
.cfi_restore $23
.cfi_restore $24
.cfi_restore $25
.cfi_restore $26
.cfi_restore $27
.cfi_restore $28
.cfi_restore $29
.cfi_adjust_cfa_offset -256
call_pal PAL_rti
.align 4
entUnaUser:
.cfi_restore_state
ldq $0, 0($sp) /* restore original $0 */
lda $sp, 256($sp) /* pop entUna's stack frame */
.cfi_restore $0
.cfi_adjust_cfa_offset -256
SAVE_ALL /* setup normal kernel stack */
lda $sp, -56($sp)
.cfi_adjust_cfa_offset 56
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)
.cfi_rel_offset $9, 0
.cfi_rel_offset $10, 8
.cfi_rel_offset $11, 16
.cfi_rel_offset $12, 24
.cfi_rel_offset $13, 32
.cfi_rel_offset $14, 40
.cfi_rel_offset $15, 48
lda $8, 0x3fff
addq $sp, 56, $19
bic $sp, $8, $8
jsr $26, do_entUnaUser
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)
lda $sp, 56($sp)
.cfi_restore $9
.cfi_restore $10
.cfi_restore $11
.cfi_restore $12
.cfi_restore $13
.cfi_restore $14
.cfi_restore $15
.cfi_adjust_cfa_offset -56
br ret_from_sys_call
CFI_END_OSF_FRAME entUna
CFI_START_OSF_FRAME entDbg
SAVE_ALL
lda $8, 0x3fff
lda $26, ret_from_sys_call
bic $sp, $8, $8
mov $sp, $16
jsr $31, do_entDbg
CFI_END_OSF_FRAME entDbg
/*
* The system call entry point is special. Most importantly, it looks
* like a function call to userspace as far as clobbered registers. We
* do preserve the argument registers (for syscall restarts) and $26
* (for leaf syscall functions).
*
* So much for theory. We don't take advantage of this yet.
*
* Note that a0-a2 are not saved by PALcode as with the other entry points.
*/
.align 4
.globl entSys
.type entSys, @function
.cfi_startproc simple
.cfi_return_column 64
.cfi_def_cfa $sp, 48
.cfi_rel_offset 64, 8
.cfi_rel_offset $gp, 16
entSys:
SAVE_ALL
lda $8, 0x3fff
bic $sp, $8, $8
lda $4, NR_SYSCALLS($31)
stq $16, SP_OFF+24($sp)
lda $5, sys_call_table
lda $27, sys_ni_syscall
cmpult $0, $4, $4
ldl $3, TI_FLAGS($8)
stq $17, SP_OFF+32($sp)
s8addq $0, $5, $5
stq $18, SP_OFF+40($sp)
.cfi_rel_offset $16, SP_OFF+24
.cfi_rel_offset $17, SP_OFF+32
.cfi_rel_offset $18, SP_OFF+40
#ifdef CONFIG_AUDITSYSCALL
lda $6, _TIF_SYSCALL_TRACE | _TIF_SYSCALL_AUDIT
and $3, $6, $3
#endif
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
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