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Auto merge with /home/aegl/GIT/ia64-test

This commit is contained in:
Tony Luck 2005-06-28 08:24:49 -07:00
parent 99f95e5286 f2cbb4f019
commit 54522b6613
6 changed files with 308 additions and 233 deletions
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120
arch/ia64/kernel/entry.S
View File

@ -470,18 +470,6 @@ ENTRY(load_switch_stack)
br.cond.sptk.many b7
END(load_switch_stack)
GLOBAL_ENTRY(__ia64_syscall)
.regstk 6,0,0,0
mov r15=in5 // put syscall number in place
break __BREAK_SYSCALL
movl r2=errno
cmp.eq p6,p7=-1,r10
;;
(p6) st4 [r2]=r8
(p6) mov r8=-1
br.ret.sptk.many rp
END(__ia64_syscall)
GLOBAL_ENTRY(execve)
mov r15=__NR_execve // put syscall number in place
break __BREAK_SYSCALL
@ -637,7 +625,7 @@ END(ia64_ret_from_syscall)
* r8-r11: restored (syscall return value(s))
* r12: restored (user-level stack pointer)
* r13: restored (user-level thread pointer)
* r14: cleared
* r14: set to __kernel_syscall_via_epc
* r15: restored (syscall #)
* r16-r17: cleared
* r18: user-level b6
@ -658,7 +646,7 @@ END(ia64_ret_from_syscall)
* pr: restored (user-level pr)
* b0: restored (user-level rp)
* b6: restored
* b7: cleared
* b7: set to __kernel_syscall_via_epc
* ar.unat: restored (user-level ar.unat)
* ar.pfs: restored (user-level ar.pfs)
* ar.rsc: restored (user-level ar.rsc)
@ -704,72 +692,79 @@ ENTRY(ia64_leave_syscall)
;;
(p6) ld4 r31=[r18] // load current_thread_info()->flags
ld8 r19=[r2],PT(B6)-PT(LOADRS) // load ar.rsc value for "loadrs"
mov b7=r0 // clear b7
nop.i 0
;;
ld8 r23=[r3],PT(R11)-PT(AR_BSPSTORE) // load ar.bspstore (may be garbage)
mov r16=ar.bsp // M2 get existing backing store pointer
ld8 r18=[r2],PT(R9)-PT(B6) // load b6
(p6) and r15=TIF_WORK_MASK,r31 // any work other than TIF_SYSCALL_TRACE?
;;
mov r16=ar.bsp // M2 get existing backing store pointer
ld8 r23=[r3],PT(R11)-PT(AR_BSPSTORE) // load ar.bspstore (may be garbage)
(p6) cmp4.ne.unc p6,p0=r15, r0 // any special work pending?
(p6) br.cond.spnt .work_pending_syscall
;;
// start restoring the state saved on the kernel stack (struct pt_regs):
ld8 r9=[r2],PT(CR_IPSR)-PT(R9)
ld8 r11=[r3],PT(CR_IIP)-PT(R11)
mov f6=f0 // clear f6
(pNonSys) break 0 // bug check: we shouldn't be here if pNonSys is TRUE!
;;
invala // M0|1 invalidate ALAT
rsm psr.i | psr.ic // M2 initiate turning off of interrupt and interruption collection
mov f9=f0 // clear f9
rsm psr.i | psr.ic // M2 turn off interrupts and interruption collection
cmp.eq p9,p0=r0,r0 // A set p9 to indicate that we should restore cr.ifs
ld8 r29=[r2],16 // load cr.ipsr
ld8 r28=[r3],16 // load cr.iip
mov f8=f0 // clear f8
ld8 r29=[r2],16 // M0|1 load cr.ipsr
ld8 r28=[r3],16 // M0|1 load cr.iip
mov r22=r0 // A clear r22
;;
ld8 r30=[r2],16 // M0|1 load cr.ifs
ld8 r25=[r3],16 // M0|1 load ar.unat
cmp.eq p9,p0=r0,r0 // set p9 to indicate that we should restore cr.ifs
;;
ld8 r26=[r2],PT(B0)-PT(AR_PFS) // M0|1 load ar.pfs
(pKStk) mov r22=psr // M2 read PSR now that interrupts are disabled
mov f10=f0 // clear f10
;;
ld8 r21=[r2],PT(AR_RNAT)-PT(B0) // load b0
ld8 r27=[r3],PT(PR)-PT(AR_RSC) // load ar.rsc
mov f11=f0 // clear f11
;;
ld8 r24=[r2],PT(AR_FPSR)-PT(AR_RNAT) // load ar.rnat (may be garbage)
ld8 r31=[r3],PT(R1)-PT(PR) // load predicates
(pUStk) add r14=IA64_TASK_THREAD_ON_USTACK_OFFSET,r13
;;
ld8 r20=[r2],PT(R12)-PT(AR_FPSR) // load ar.fpsr
ld8.fill r1=[r3],16 // load r1
(pUStk) mov r17=1
ld8 r26=[r2],PT(B0)-PT(AR_PFS) // M0|1 load ar.pfs
(pKStk) mov r22=psr // M2 read PSR now that interrupts are disabled
nop 0
;;
srlz.d // M0 ensure interruption collection is off
ld8.fill r13=[r3],16
mov f7=f0 // clear f7
ld8 r21=[r2],PT(AR_RNAT)-PT(B0) // M0|1 load b0
ld8 r27=[r3],PT(PR)-PT(AR_RSC) // M0|1 load ar.rsc
mov f6=f0 // F clear f6
;;
ld8.fill r12=[r2] // restore r12 (sp)
mov.m ar.ssd=r0 // M2 clear ar.ssd
mov r22=r0 // clear r22
ld8 r24=[r2],PT(AR_FPSR)-PT(AR_RNAT) // M0|1 load ar.rnat (may be garbage)
ld8 r31=[r3],PT(R1)-PT(PR) // M0|1 load predicates
mov f7=f0 // F clear f7
;;
ld8 r20=[r2],PT(R12)-PT(AR_FPSR) // M0|1 load ar.fpsr
ld8.fill r1=[r3],16 // M0|1 load r1
(pUStk) mov r17=1 // A
;;
(pUStk) st1 [r14]=r17 // M2|3
ld8.fill r13=[r3],16 // M0|1
mov f8=f0 // F clear f8
;;
ld8.fill r12=[r2] // M0|1 restore r12 (sp)
ld8.fill r15=[r3] // M0|1 restore r15
mov b6=r18 // I0 restore b6
ld8.fill r15=[r3] // restore r15
(pUStk) st1 [r14]=r17
addl r3=THIS_CPU(ia64_phys_stacked_size_p8),r0
;;
(pUStk) ld4 r17=[r3] // r17 = cpu_data->phys_stacked_size_p8
mov.m ar.csd=r0 // M2 clear ar.csd
mov b6=r18 // I0 restore b6
;;
mov r14=r0 // clear r14
shr.u r18=r19,16 // I0|1 get byte size of existing "dirty" partition
(pKStk) br.cond.dpnt.many skip_rbs_switch
addl r17=THIS_CPU(ia64_phys_stacked_size_p8),r0 // A
mov f9=f0 // F clear f9
(pKStk) br.cond.dpnt.many skip_rbs_switch // B
mov.m ar.ccv=r0 // clear ar.ccv
(pNonSys) br.cond.dpnt.many dont_preserve_current_frame
br.cond.sptk.many rbs_switch
srlz.d // M0 ensure interruption collection is off (for cover)
shr.u r18=r19,16 // I0|1 get byte size of existing "dirty" partition
cover // B add current frame into dirty partition & set cr.ifs
;;
(pUStk) ld4 r17=[r17] // M0|1 r17 = cpu_data->phys_stacked_size_p8
mov r19=ar.bsp // M2 get new backing store pointer
mov f10=f0 // F clear f10
nop.m 0
movl r14=__kernel_syscall_via_epc // X
;;
mov.m ar.csd=r0 // M2 clear ar.csd
mov.m ar.ccv=r0 // M2 clear ar.ccv
mov b7=r14 // I0 clear b7 (hint with __kernel_syscall_via_epc)
mov.m ar.ssd=r0 // M2 clear ar.ssd
mov f11=f0 // F clear f11
br.cond.sptk.many rbs_switch // B
END(ia64_leave_syscall)
#ifdef CONFIG_IA32_SUPPORT
@ -885,7 +880,7 @@ GLOBAL_ENTRY(ia64_leave_kernel)
ldf.fill f7=[r2],PT(F11)-PT(F7)
ldf.fill f8=[r3],32
;;
srlz.i // ensure interruption collection is off
srlz.d // ensure that inter. collection is off (VHPT is don't care, since text is pinned)
mov ar.ccv=r15
;;
ldf.fill f11=[r2]
@ -945,11 +940,10 @@ GLOBAL_ENTRY(ia64_leave_kernel)
* NOTE: alloc, loadrs, and cover can't be predicated.
*/
(pNonSys) br.cond.dpnt dont_preserve_current_frame
rbs_switch:
cover // add current frame into dirty partition and set cr.ifs
;;
mov r19=ar.bsp // get new backing store pointer
rbs_switch:
sub r16=r16,r18 // krbs = old bsp - size of dirty partition
cmp.ne p9,p0=r0,r0 // clear p9 to skip restore of cr.ifs
;;
@ -1024,14 +1018,14 @@ rse_clear_invalid:
mov loc5=0
mov loc6=0
mov loc7=0
(pRecurse) br.call.sptk.few b0=rse_clear_invalid
(pRecurse) br.call.dptk.few b0=rse_clear_invalid
;;
mov loc8=0
mov loc9=0
cmp.ne pReturn,p0=r0,in1 // if recursion count != 0, we need to do a br.ret
mov loc10=0
mov loc11=0
(pReturn) br.ret.sptk.many b0
(pReturn) br.ret.dptk.many b0
#endif /* !CONFIG_ITANIUM */
# undef pRecurse
# undef pReturn

151
arch/ia64/kernel/fsys.S
View File

@ -531,93 +531,114 @@ GLOBAL_ENTRY(fsys_bubble_down)
.altrp b6
.body
/*
* We get here for syscalls that don't have a lightweight handler. For those, we
* need to bubble down into the kernel and that requires setting up a minimal
* pt_regs structure, and initializing the CPU state more or less as if an
* interruption had occurred. To make syscall-restarts work, we setup pt_regs
* such that cr_iip points to the second instruction in syscall_via_break.
* Decrementing the IP hence will restart the syscall via break and not
* decrementing IP will return us to the caller, as usual. Note that we preserve
* the value of psr.pp rather than initializing it from dcr.pp. This makes it
* possible to distinguish fsyscall execution from other privileged execution.
* We get here for syscalls that don't have a lightweight
* handler. For those, we need to bubble down into the kernel
* and that requires setting up a minimal pt_regs structure,
* and initializing the CPU state more or less as if an
* interruption had occurred. To make syscall-restarts work,
* we setup pt_regs such that cr_iip points to the second
* instruction in syscall_via_break. Decrementing the IP
* hence will restart the syscall via break and not
* decrementing IP will return us to the caller, as usual.
* Note that we preserve the value of psr.pp rather than
* initializing it from dcr.pp. This makes it possible to
* distinguish fsyscall execution from other privileged
* execution.
*
* On entry:
* - normal fsyscall handler register usage, except that we also have:
* - normal fsyscall handler register usage, except
* that we also have:
* - r18: address of syscall entry point
* - r21: ar.fpsr
* - r26: ar.pfs
* - r27: ar.rsc
* - r29: psr
*
* We used to clear some PSR bits here but that requires slow
* serialization. Fortuntely, that isn't really necessary.
* The rationale is as follows: we used to clear bits
* ~PSR_PRESERVED_BITS in PSR.L. Since
* PSR_PRESERVED_BITS==PSR.{UP,MFL,MFH,PK,DT,PP,SP,RT,IC}, we
* ended up clearing PSR.{BE,AC,I,DFL,DFH,DI,DB,SI,TB}.
* However,
*
* PSR.BE : already is turned off in __kernel_syscall_via_epc()
* PSR.AC : don't care (kernel normally turns PSR.AC on)
* PSR.I : already turned off by the time fsys_bubble_down gets
* invoked
* PSR.DFL: always 0 (kernel never turns it on)
* PSR.DFH: don't care --- kernel never touches f32-f127 on its own
* initiative
* PSR.DI : always 0 (kernel never turns it on)
* PSR.SI : always 0 (kernel never turns it on)
* PSR.DB : don't care --- kernel never enables kernel-level
* breakpoints
* PSR.TB : must be 0 already; if it wasn't zero on entry to
* __kernel_syscall_via_epc, the branch to fsys_bubble_down
* will trigger a taken branch; the taken-trap-handler then
* converts the syscall into a break-based system-call.
*/
# define PSR_PRESERVED_BITS (IA64_PSR_UP | IA64_PSR_MFL | IA64_PSR_MFH | IA64_PSR_PK \
| IA64_PSR_DT | IA64_PSR_PP | IA64_PSR_SP | IA64_PSR_RT \
| IA64_PSR_IC)
/*
* Reading psr.l gives us only bits 0-31, psr.it, and psr.mc. The rest we have
* to synthesize.
* Reading psr.l gives us only bits 0-31, psr.it, and psr.mc.
* The rest we have to synthesize.
*/
# define PSR_ONE_BITS ((3 << IA64_PSR_CPL0_BIT) | (0x1 << IA64_PSR_RI_BIT) \
# define PSR_ONE_BITS ((3 << IA64_PSR_CPL0_BIT) \
| (0x1 << IA64_PSR_RI_BIT) \
| IA64_PSR_BN | IA64_PSR_I)
invala
movl r8=PSR_ONE_BITS
invala // M0|1
movl r14=ia64_ret_from_syscall // X
mov r25=ar.unat // save ar.unat (5 cyc)
movl r9=PSR_PRESERVED_BITS
nop.m 0
movl r28=__kernel_syscall_via_break // X create cr.iip
;;
mov ar.rsc=0 // set enforced lazy mode, pl 0, little-endian, loadrs=0
movl r28=__kernel_syscall_via_break
mov r2=r16 // A get task addr to addl-addressable register
adds r16=IA64_TASK_THREAD_ON_USTACK_OFFSET,r16 // A
mov r31=pr // I0 save pr (2 cyc)
;;
mov r23=ar.bspstore // save ar.bspstore (12 cyc)
mov r31=pr // save pr (2 cyc)
mov r20=r1 // save caller's gp in r20
st1 [r16]=r0 // M2|3 clear current->thread.on_ustack flag
addl r22=IA64_RBS_OFFSET,r2 // A compute base of RBS
add r3=TI_FLAGS+IA64_TASK_SIZE,r2 // A
;;
mov r2=r16 // copy current task addr to addl-addressable register
and r9=r9,r29
mov r19=b6 // save b6 (2 cyc)
ld4 r3=[r3] // M0|1 r3 = current_thread_info()->flags
lfetch.fault.excl.nt1 [r22] // M0|1 prefetch register backing-store
nop.i 0
;;
mov psr.l=r9 // slam the door (17 cyc to srlz.i)
or r29=r8,r29 // construct cr.ipsr value to save
addl r22=IA64_RBS_OFFSET,r2 // compute base of RBS
mov ar.rsc=0 // M2 set enforced lazy mode, pl 0, LE, loadrs=0
nop.m 0
nop.i 0
;;
// GAS reports a spurious RAW hazard on the read of ar.rnat because it thinks
// we may be reading ar.itc after writing to psr.l. Avoid that message with
// this directive:
dv_serialize_data
mov.m r24=ar.rnat // read ar.rnat (5 cyc lat)
lfetch.fault.excl.nt1 [r22]
adds r16=IA64_TASK_THREAD_ON_USTACK_OFFSET,r2
mov r23=ar.bspstore // M2 (12 cyc) save ar.bspstore
mov.m r24=ar.rnat // M2 (5 cyc) read ar.rnat (dual-issues!)
nop.i 0
;;
mov ar.bspstore=r22 // M2 (6 cyc) switch to kernel RBS
movl r8=PSR_ONE_BITS // X
;;
mov r25=ar.unat // M2 (5 cyc) save ar.unat
mov r19=b6 // I0 save b6 (2 cyc)
mov r20=r1 // A save caller's gp in r20
;;
or r29=r8,r29 // A construct cr.ipsr value to save
mov b6=r18 // I0 copy syscall entry-point to b6 (7 cyc)
addl r1=IA64_STK_OFFSET-IA64_PT_REGS_SIZE,r2 // A compute base of memory stack
// ensure previous insn group is issued before we stall for srlz.i:
mov r18=ar.bsp // M2 save (kernel) ar.bsp (12 cyc)
cmp.ne pKStk,pUStk=r0,r0 // A set pKStk <- 0, pUStk <- 1
br.call.sptk.many b7=ia64_syscall_setup // B
;;
srlz.i // ensure new psr.l has been established
/////////////////////////////////////////////////////////////////////////////
////////// from this point on, execution is not interruptible anymore
/////////////////////////////////////////////////////////////////////////////
addl r1=IA64_STK_OFFSET-IA64_PT_REGS_SIZE,r2 // compute base of memory stack
cmp.ne pKStk,pUStk=r0,r0 // set pKStk <- 0, pUStk <- 1
mov ar.rsc=0x3 // M2 set eager mode, pl 0, LE, loadrs=0
mov rp=r14 // I0 set the real return addr
and r3=_TIF_SYSCALL_TRACEAUDIT,r3 // A
;;
st1 [r16]=r0 // clear current->thread.on_ustack flag
mov ar.bspstore=r22 // switch to kernel RBS
mov b6=r18 // copy syscall entry-point to b6 (7 cyc)
add r3=TI_FLAGS+IA64_TASK_SIZE,r2
;;
ld4 r3=[r3] // r2 = current_thread_info()->flags
mov r18=ar.bsp // save (kernel) ar.bsp (12 cyc)
mov ar.rsc=0x3 // set eager mode, pl 0, little-endian, loadrs=0
br.call.sptk.many b7=ia64_syscall_setup
;;
ssm psr.i
movl r2=ia64_ret_from_syscall
;;
mov rp=r2 // set the real return addr
and r3=_TIF_SYSCALL_TRACEAUDIT,r3
;;
cmp.eq p8,p0=r3,r0
ssm psr.i // M2 we're on kernel stacks now, reenable irqs
cmp.eq p8,p0=r3,r0 // A
(p10) br.cond.spnt.many ia64_ret_from_syscall // B return if bad call-frame or r15 is a NaT
(p10) br.cond.spnt.many ia64_ret_from_syscall // p10==true means out registers are more than 8
(p8) br.call.sptk.many b6=b6 // ignore this return addr
br.cond.sptk ia64_trace_syscall
nop.m 0
(p8) br.call.sptk.many b6=b6 // B (ignore return address)
br.cond.spnt ia64_trace_syscall // B
END(fsys_bubble_down)
.rodata

64
arch/ia64/kernel/gate.S
View File

@ -72,38 +72,40 @@ GLOBAL_ENTRY(__kernel_syscall_via_epc)
* bundle get executed. The remaining code must be safe even if
* they do not get executed.
*/
adds r17=-1024,r15
mov r10=0 // default to successful syscall execution
epc
adds r17=-1024,r15 // A
mov r10=0 // A default to successful syscall execution
epc // B causes split-issue
}
;;
rsm psr.be // note: on McKinley "rsm psr.be/srlz.d" is slightly faster than "rum psr.be"
LOAD_FSYSCALL_TABLE(r14)
rsm psr.be | psr.i // M2 (5 cyc to srlz.d)
LOAD_FSYSCALL_TABLE(r14) // X
;;
mov r16=IA64_KR(CURRENT) // M2 (12 cyc)
shladd r18=r17,3,r14 // A
mov r19=NR_syscalls-1 // A
;;
lfetch [r18] // M0|1
mov r29=psr // M2 (12 cyc)
// If r17 is a NaT, p6 will be zero
cmp.geu p6,p7=r19,r17 // A (sysnr > 0 && sysnr < 1024+NR_syscalls)?
;;
mov r21=ar.fpsr // M2 (12 cyc)
tnat.nz p10,p9=r15 // I0
mov.i r26=ar.pfs // I0 (would stall anyhow due to srlz.d...)
;;
srlz.d // M0 (forces split-issue) ensure PSR.BE==0
(p6) ld8 r18=[r18] // M0|1
nop.i 0
;;
nop.m 0
(p6) tbit.z.unc p8,p0=r18,0 // I0 (dual-issues with "mov b7=r18"!)
nop.i 0
;;
(p8) ssm psr.i
(p6) mov b7=r18 // I0
(p8) br.dptk.many b7 // B
mov r16=IA64_KR(CURRENT) // 12 cycle read latency
tnat.nz p10,p9=r15
mov r19=NR_syscalls-1
;;
shladd r18=r17,3,r14
srlz.d
cmp.ne p8,p0=r0,r0 // p8 <- FALSE
/* Note: if r17 is a NaT, p6 will be set to zero. */
cmp.geu p6,p7=r19,r17 // (syscall > 0 && syscall < 1024+NR_syscalls)?
;;
(p6) ld8 r18=[r18]
mov r21=ar.fpsr
add r14=-8,r14 // r14 <- addr of fsys_bubble_down entry
;;
(p6) mov b7=r18
(p6) tbit.z p8,p0=r18,0
(p8) br.dptk.many b7
(p6) rsm psr.i
mov r27=ar.rsc
mov r26=ar.pfs
;;
mov r29=psr // read psr (12 cyc load latency)
mov r27=ar.rsc // M2 (12 cyc)
/*
* brl.cond doesn't work as intended because the linker would convert this branch
* into a branch to a PLT. Perhaps there will be a way to avoid this with some
@ -111,6 +113,8 @@ GLOBAL_ENTRY(__kernel_syscall_via_epc)
* instead.
*/
#ifdef CONFIG_ITANIUM
(p6) add r14=-8,r14 // r14 <- addr of fsys_bubble_down entry
;;
(p6) ld8 r14=[r14] // r14 <- fsys_bubble_down
;;
(p6) mov b7=r14
@ -118,7 +122,7 @@ GLOBAL_ENTRY(__kernel_syscall_via_epc)
#else
BRL_COND_FSYS_BUBBLE_DOWN(p6)
#endif
ssm psr.i
mov r10=-1
(p10) mov r8=EINVAL
(p9) mov r8=ENOSYS

3
arch/ia64/kernel/ia64_ksyms.c
View File

@ -58,9 +58,6 @@ EXPORT_SYMBOL(__strlen_user);
EXPORT_SYMBOL(__strncpy_from_user);
EXPORT_SYMBOL(__strnlen_user);
#include <asm/unistd.h>
EXPORT_SYMBOL(__ia64_syscall);
/* from arch/ia64/lib */
extern void __divsi3(void);
extern void __udivsi3(void);

181
arch/ia64/kernel/ivt.S
View File

@ -1,7 +1,7 @@
/*
* arch/ia64/kernel/ivt.S
*
* Copyright (C) 1998-2001, 2003 Hewlett-Packard Co
* Copyright (C) 1998-2001, 2003, 2005 Hewlett-Packard Co
* Stephane Eranian <eranian@hpl.hp.com>
* David Mosberger <davidm@hpl.hp.com>
* Copyright (C) 2000, 2002-2003 Intel Co
@ -692,82 +692,118 @@ ENTRY(break_fault)
* to prevent leaking bits from kernel to user level.
*/
DBG_FAULT(11)
mov r16=IA64_KR(CURRENT) // r16 = current task; 12 cycle read lat.
mov r17=cr.iim
mov r18=__IA64_BREAK_SYSCALL
mov r21=ar.fpsr
mov r29=cr.ipsr
mov r19=b6
mov r25=ar.unat
mov r27=ar.rsc
mov r26=ar.pfs
mov r28=cr.iip
mov r31=pr // prepare to save predicates
mov r20=r1
mov.m r16=IA64_KR(CURRENT) // M2 r16 <- current task (12 cyc)
mov r29=cr.ipsr // M2 (12 cyc)
mov r31=pr // I0 (2 cyc)
mov r17=cr.iim // M2 (2 cyc)
mov.m r27=ar.rsc // M2 (12 cyc)
mov r18=__IA64_BREAK_SYSCALL // A
mov.m ar.rsc=0 // M2
mov.m r21=ar.fpsr // M2 (12 cyc)
mov r19=b6 // I0 (2 cyc)
;;
mov.m r23=ar.bspstore // M2 (12 cyc)
mov.m r24=ar.rnat // M2 (5 cyc)
mov.i r26=ar.pfs // I0 (2 cyc)
invala // M0|1
nop.m 0 // M
mov r20=r1 // A save r1
nop.m 0
movl r30=sys_call_table // X
mov r28=cr.iip // M2 (2 cyc)
cmp.eq p0,p7=r18,r17 // I0 is this a system call?
(p7) br.cond.spnt non_syscall // B no ->
//
// From this point on, we are definitely on the syscall-path
// and we can use (non-banked) scratch registers.
//
///////////////////////////////////////////////////////////////////////
mov r1=r16 // A move task-pointer to "addl"-addressable reg
mov r2=r16 // A setup r2 for ia64_syscall_setup
add r9=TI_FLAGS+IA64_TASK_SIZE,r16 // A r9 = &current_thread_info()->flags
adds r16=IA64_TASK_THREAD_ON_USTACK_OFFSET,r16
cmp.eq p0,p7=r18,r17 // is this a system call? (p7 <- false, if so)
(p7) br.cond.spnt non_syscall
;;
ld1 r17=[r16] // load current->thread.on_ustack flag
st1 [r16]=r0 // clear current->thread.on_ustack flag
add r1=-IA64_TASK_THREAD_ON_USTACK_OFFSET,r16 // set r1 for MINSTATE_START_SAVE_MIN_VIRT
;;
invala
/* adjust return address so we skip over the break instruction: */
extr.u r8=r29,41,2 // extract ei field from cr.ipsr
;;
cmp.eq p6,p7=2,r8 // isr.ei==2?
mov r2=r1 // setup r2 for ia64_syscall_setup
;;
(p6) mov r8=0 // clear ei to 0
(p6) adds r28=16,r28 // switch cr.iip to next bundle cr.ipsr.ei wrapped
(p7) adds r8=1,r8 // increment ei to next slot
;;
cmp.eq pKStk,pUStk=r0,r17 // are we in kernel mode already?
dep r29=r8,r29,41,2 // insert new ei into cr.ipsr
;;
// switch from user to kernel RBS:
MINSTATE_START_SAVE_MIN_VIRT
br.call.sptk.many b7=ia64_syscall_setup
;;
MINSTATE_END_SAVE_MIN_VIRT // switch to bank 1
ssm psr.ic | PSR_DEFAULT_BITS
;;
srlz.i // guarantee that interruption collection is on
adds r15=-1024,r15 // A subtract 1024 from syscall number
mov r3=NR_syscalls - 1
;;
(p15) ssm psr.i // restore psr.i
// p10==true means out registers are more than 8 or r15's Nat is true
(p10) br.cond.spnt.many ia64_ret_from_syscall
;;
movl r16=sys_call_table
ld1.bias r17=[r16] // M0|1 r17 = current->thread.on_ustack flag
ld4 r9=[r9] // M0|1 r9 = current_thread_info()->flags
extr.u r8=r29,41,2 // I0 extract ei field from cr.ipsr
adds r15=-1024,r15 // r15 contains the syscall number---subtract 1024
movl r2=ia64_ret_from_syscall
shladd r30=r15,3,r30 // A r30 = sys_call_table + 8*(syscall-1024)
addl r22=IA64_RBS_OFFSET,r1 // A compute base of RBS
cmp.leu p6,p7=r15,r3 // A syscall number in range?
;;
shladd r20=r15,3,r16 // r20 = sys_call_table + 8*(syscall-1024)
cmp.leu p6,p7=r15,r3 // (syscall > 0 && syscall < 1024 + NR_syscalls) ?
mov rp=r2 // set the real return addr
;;
(p6) ld8 r20=[r20] // load address of syscall entry point
(p7) movl r20=sys_ni_syscall
add r2=TI_FLAGS+IA64_TASK_SIZE,r13
lfetch.fault.excl.nt1 [r22] // M0|1 prefetch RBS
(p6) ld8 r30=[r30] // M0|1 load address of syscall entry point
tnat.nz.or p7,p0=r15 // I0 is syscall nr a NaT?
mov.m ar.bspstore=r22 // M2 switch to kernel RBS
cmp.eq p8,p9=2,r8 // A isr.ei==2?
;;
ld4 r2=[r2] // r2 = current_thread_info()->flags
(p8) mov r8=0 // A clear ei to 0
(p7) movl r30=sys_ni_syscall // X
(p8) adds r28=16,r28 // A switch cr.iip to next bundle
(p9) adds r8=1,r8 // A increment ei to next slot
nop.i 0
;;
and r2=_TIF_SYSCALL_TRACEAUDIT,r2 // mask trace or audit
mov.m r25=ar.unat // M2 (5 cyc)
dep r29=r8,r29,41,2 // I0 insert new ei into cr.ipsr
adds r15=1024,r15 // A restore original syscall number
//
// If any of the above loads miss in L1D, we'll stall here until
// the data arrives.
//
///////////////////////////////////////////////////////////////////////
st1 [r16]=r0 // M2|3 clear current->thread.on_ustack flag
mov b6=r30 // I0 setup syscall handler branch reg early
cmp.eq pKStk,pUStk=r0,r17 // A were we on kernel stacks already?
and r9=_TIF_SYSCALL_TRACEAUDIT,r9 // A mask trace or audit
mov r18=ar.bsp // M2 (12 cyc)
(pKStk) br.cond.spnt .break_fixup // B we're already in kernel-mode -- fix up RBS
;;
cmp.eq p8,p0=r2,r0
mov b6=r20
.back_from_break_fixup:
(pUStk) addl r1=IA64_STK_OFFSET-IA64_PT_REGS_SIZE,r1 // A compute base of memory stack
cmp.eq p14,p0=r9,r0 // A are syscalls being traced/audited?
br.call.sptk.many b7=ia64_syscall_setup // B
1:
mov ar.rsc=0x3 // M2 set eager mode, pl 0, LE, loadrs=0
nop 0
bsw.1 // B (6 cyc) regs are saved, switch to bank 1
;;
(p8) br.call.sptk.many b6=b6 // ignore this return addr
br.cond.sptk ia64_trace_syscall
ssm psr.ic | PSR_DEFAULT_BITS // M2 now it's safe to re-enable intr.-collection
movl r3=ia64_ret_from_syscall // X
;;
srlz.i // M0 ensure interruption collection is on
mov rp=r3 // I0 set the real return addr
(p10) br.cond.spnt.many ia64_ret_from_syscall // B return if bad call-frame or r15 is a NaT
(p15) ssm psr.i // M2 restore psr.i
(p14) br.call.sptk.many b6=b6 // B invoke syscall-handker (ignore return addr)
br.cond.spnt.many ia64_trace_syscall // B do syscall-tracing thingamagic
// NOT REACHED
///////////////////////////////////////////////////////////////////////
// On entry, we optimistically assumed that we're coming from user-space.
// For the rare cases where a system-call is done from within the kernel,
// we fix things up at this point:
.break_fixup:
add r1=-IA64_PT_REGS_SIZE,sp // A allocate space for pt_regs structure
mov ar.rnat=r24 // M2 restore kernel's AR.RNAT
;;
mov ar.bspstore=r23 // M2 restore kernel's AR.BSPSTORE
br.cond.sptk .back_from_break_fixup
END(break_fault)
.org ia64_ivt+0x3000
@ -842,8 +878,6 @@ END(interrupt)
* - r31: saved pr
* - b0: original contents (to be saved)
* On exit:
* - executing on bank 1 registers
* - psr.ic enabled, interrupts restored
* - p10: TRUE if syscall is invoked with more than 8 out
* registers or r15's Nat is true
* - r1: kernel's gp
@ -851,8 +885,11 @@ END(interrupt)
* - r8: -EINVAL if p10 is true
* - r12: points to kernel stack
* - r13: points to current task
* - r14: preserved (same as on entry)
* - p13: preserved
* - p15: TRUE if interrupts need to be re-enabled
* - ar.fpsr: set to kernel settings
* - b6: preserved (same as on entry)
*/
GLOBAL_ENTRY(ia64_syscall_setup)
#if PT(B6) != 0
@ -920,10 +957,10 @@ GLOBAL_ENTRY(ia64_syscall_setup)
(p13) mov in5=-1
;;
st8 [r16]=r21,PT(R8)-PT(AR_FPSR) // save ar.fpsr
tnat.nz p14,p0=in6
tnat.nz p13,p0=in6
cmp.lt p10,p9=r11,r8 // frame size can't be more than local+8
;;
stf8 [r16]=f1 // ensure pt_regs.r8 != 0 (see handle_syscall_error)
mov r8=1
(p9) tnat.nz p10,p0=r15
adds r12=-16,r1 // switch to kernel memory stack (with 16 bytes of scratch)
@ -934,9 +971,9 @@ GLOBAL_ENTRY(ia64_syscall_setup)
mov r13=r2 // establish `current'
movl r1=__gp // establish kernel global pointer
;;
(p14) mov in6=-1
st8 [r16]=r8 // ensure pt_regs.r8 != 0 (see handle_syscall_error)
(p13) mov in6=-1
(p8) mov in7=-1
nop.i 0
cmp.eq pSys,pNonSys=r0,r0 // set pSys=1, pNonSys=0
movl r17=FPSR_DEFAULT
@ -1007,6 +1044,8 @@ END(dispatch_illegal_op_fault)
FAULT(17)
ENTRY(non_syscall)
mov ar.rsc=r27 // restore ar.rsc before SAVE_MIN_WITH_COVER
;;
SAVE_MIN_WITH_COVER
// There is no particular reason for this code to be here, other than that

22
arch/ia64/kernel/ptrace.c
View File

@ -725,12 +725,32 @@ convert_to_non_syscall (struct task_struct *child, struct pt_regs *pt,
break;
}
/*
* Note: at the time of this call, the target task is blocked
* in notify_resume_user() and by clearling PRED_LEAVE_SYSCALL
* (aka, "pLvSys") we redirect execution from
* .work_pending_syscall_end to .work_processed_kernel.
*/
unw_get_pr(&prev_info, &pr);
pr &= ~(1UL << PRED_SYSCALL);
pr &= ~((1UL << PRED_SYSCALL) | (1UL << PRED_LEAVE_SYSCALL));
pr |= (1UL << PRED_NON_SYSCALL);
unw_set_pr(&prev_info, pr);
pt->cr_ifs = (1UL << 63) | cfm;
/*
* Clear the memory that is NOT written on syscall-entry to
* ensure we do not leak kernel-state to user when execution
* resumes.
*/
pt->r2 = 0;
pt->r3 = 0;
pt->r14 = 0;
memset(&pt->r16, 0, 16*8); /* clear r16-r31 */
memset(&pt->f6, 0, 6*16); /* clear f6-f11 */
pt->b7 = 0;
pt->ar_ccv = 0;
pt->ar_csd = 0;
pt->ar_ssd = 0;
}
static int