ChangeSet 1.1463, 2005/03/12 15:38:36-07:00, [EMAIL PROTECTED]
[IA64] clean up ptrace corner cases
Patch from [EMAIL PROTECTED] to fix up some corner cases
in ptrace. Many thanks to davidm for reviewing and improving.
Backported to 2.4 by Bjorn Helgaas ([EMAIL PROTECTED]).
entry.S | 26 +++++++++++++++++++-------
ivt.S | 47 +++++++++++++++++++++++++----------------------
process.c | 2 +-
3 files changed, 45 insertions(+), 30 deletions(-)
diff -Nru a/arch/ia64/kernel/entry.S b/arch/ia64/kernel/entry.S
--- a/arch/ia64/kernel/entry.S 2005-03-24 09:05:06 -08:00
+++ b/arch/ia64/kernel/entry.S 2005-03-24 09:05:06 -08:00
@@ -49,8 +49,11 @@
* setup a null register window frame.
*/
ENTRY(ia64_execve)
- .prologue ASM_UNW_PRLG_RP|ASM_UNW_PRLG_PFS, ASM_UNW_PRLG_GRSAVE(3)
- alloc loc1=ar.pfs,3,2,4,0
+ /*
+ * Allocate 8 input registers since ptrace() may clobber them
+ */
+ .prologue ASM_UNW_PRLG_RP|ASM_UNW_PRLG_PFS, ASM_UNW_PRLG_GRSAVE(8)
+ alloc loc1=ar.pfs,8,2,4,0
/* Leave from kernel and restore all pt_regs to correspending
registers. This is special
* because ia32 application needs scratch registers after return from
execve.
*/
@@ -94,8 +97,11 @@
END(ia64_execve)
GLOBAL_ENTRY(sys_clone2)
- .prologue ASM_UNW_PRLG_RP|ASM_UNW_PRLG_PFS, ASM_UNW_PRLG_GRSAVE(2)
- alloc r16=ar.pfs,3,2,4,0
+ /*
+ * Allocate 8 input registers since ptrace() may clobber them
+ */
+ .prologue ASM_UNW_PRLG_RP|ASM_UNW_PRLG_PFS, ASM_UNW_PRLG_GRSAVE(8)
+ alloc r16=ar.pfs,8,2,4,0
DO_SAVE_SWITCH_STACK
mov loc0=rp
mov loc1=r16 // save ar.pfs across do_fork
@@ -113,8 +119,11 @@
END(sys_clone2)
GLOBAL_ENTRY(sys_clone)
- .prologue ASM_UNW_PRLG_RP|ASM_UNW_PRLG_PFS, ASM_UNW_PRLG_GRSAVE(2)
- alloc r16=ar.pfs,2,2,4,0
+ /*
+ * Allocate 8 input registers since ptrace() may clobber them
+ */
+ .prologue ASM_UNW_PRLG_RP|ASM_UNW_PRLG_PFS, ASM_UNW_PRLG_GRSAVE(8)
+ alloc r16=ar.pfs,8,2,4,0
DO_SAVE_SWITCH_STACK
mov loc0=rp
mov loc1=r16 // save ar.pfs across do_fork
@@ -1091,7 +1100,10 @@
ENTRY(sys_rt_sigreturn)
PT_REGS_UNWIND_INFO(0)
- alloc r2=ar.pfs,0,0,1,0
+ /*
+ * Allocate 8 input registers since ptrace() may clobber them
+ */
+ alloc r2=ar.pfs,8,0,1,0
.prologue
PT_REGS_SAVES(16)
adds sp=-16,sp
diff -Nru a/arch/ia64/kernel/ivt.S b/arch/ia64/kernel/ivt.S
--- a/arch/ia64/kernel/ivt.S 2005-03-24 09:05:06 -08:00
+++ b/arch/ia64/kernel/ivt.S 2005-03-24 09:05:06 -08:00
@@ -48,6 +48,7 @@
#include <asm/ptrace.h>
#include <asm/system.h>
#include <asm/unistd.h>
+#include <asm/errno.h>
#if 1
# define PSR_DEFAULT_BITS psr.ac
@@ -678,15 +679,29 @@
mov r1=IA64_KR(CURRENT); /* r1 = current (physical) */
;;
invala;
+
+ /* adjust return address so we skip over the break instruction: */
+
+ extr.u r8=r29,41,2 // extract ei field from cr.ipsr
extr.u r16=r29,32,2; /* extract psr.cpl */
;;
+ cmp.eq p6,p7=2,r8 // isr.ei==2?
cmp.eq pKern,pUser=r0,r16; /* are we in kernel mode
already? (psr.cpl==0) */
- /* switch from user to kernel RBS: */
;;
+(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
+ ;;
+ dep r29=r8,r29,41,2 // insert new ei into cr.ipsr
+ ;;
+
+ /* switch from user to kernel RBS: */
mov r30=r0
MINSTATE_START_SAVE_MIN_VIRT
br.call.sptk.many b7=ia64_syscall_setup
;;
+ // p10==true means out registers are more than 8 or r15's Nat is true
+(p10) br.cond.spnt.many ia64_ret_from_syscall
mov r3=255
adds r15=-1024,r15 // r15 contains the syscall
number---subtract 1024
adds r2=IA64_TASK_PTRACE_OFFSET,r13 // r2 = ¤t->ptrace
@@ -704,28 +719,9 @@
ld8 r2=[r2] // r2 = current->ptrace
mov b6=r16
- // arrange things so we skip over break instruction when returning:
-
- adds r16=PT(CR_IPSR)+16,sp // get pointer to
cr_ipsr
- adds r17=PT(CR_IIP)+16,sp // get pointer to cr_iip
;;
- ld8 r18=[r16] // fetch cr_ipsr
tbit.z p8,p0=r2,PT_TRACESYS_BIT // (current->ptrace &
PF_TRACESYS) == 0?
;;
- ld8 r19=[r17] // fetch cr_iip
- extr.u r20=r18,41,2 // extract ei field
- ;;
- cmp.eq p6,p7=2,r20 // isr.ei==2?
- adds r19=16,r19 // compute address of next
bundle
- ;;
-(p6) mov r20=0 // clear ei to 0
-(p7) adds r20=1,r20 // increment ei to next slot
- ;;
-(p6) st8 [r17]=r19 // store new cr.iip if
cr.isr.ei wrapped around
- dep r18=r20,r18,41,2 // insert new ei into cr.isr
- ;;
- st8 [r16]=r18 // store new value for cr.isr
-
(p8) br.call.sptk.many b6=b6 // ignore this return addr
br.cond.sptk ia64_trace_syscall
@@ -807,8 +803,11 @@
* - psr.ic enabled, interrupts restored
* - r1: kernel's gp
* - r3: preserved (same as on entry)
+ * - r8: -EINVAL if p10 is true
* - r12: points to kernel stack
* - r13: points to current task
+ * - p10: TRUE if syscall is invoked with more than 8 out
+ * registers or r15's Nat is true
* - p15: TRUE if interrupts need to be re-enabled
* - ar.fpsr: set to kernel settings
*/
@@ -825,12 +824,15 @@
st8 [r17]=r28,16; /* save cr.iip */
mov r28=b0;
(pKern) mov r18=r0; /* make sure r18 isn't NaT */
+ extr.u r11=r19,7,7 /* get sol of ar.pfs */
+ and r8=0x7f,r19 /* get sof of ar.pfs */
;;
(p9) mov in1=-1
tnat.nz p10,p0=in2
st8 [r16]=r30,16; /* save cr.ifs */
st8 [r17]=r25,16; /* save ar.unat */
(pUser) sub r18=r18,r22; /* r18=RSE.ndirty*8 */
+ add r11=8,r11
;;
st8 [r16]=r26,16; /* save ar.pfs */
st8 [r17]=r27,16; /* save ar.rsc */
@@ -870,12 +872,13 @@
.mem.offset 8,0; st8.spill [r17]=r15,16;
adds r12=-16,r1; /* switch to kernel memory stack (with 16 bytes
of scratch) */
;;
+ cmp.lt p10,p9=r11,r8 /* frame size can't be more than local+8 */
mov r13=IA64_KR(CURRENT); /* establish `current' */
movl r1=__gp; /* establish kernel global pointer */
;;
MINSTATE_END_SAVE_MIN_VIRT
- tnat.nz p9,p0=r15
+(p9) tnat.nz p10,p0=r15
(p8) mov in7=-1
ssm psr.ic | PSR_DEFAULT_BITS
movl r17=FPSR_DEFAULT
@@ -883,10 +886,10 @@
;;
srlz.i // guarantee that interruption
collection is on
cmp.eq pSys,pNonSys=r0,r0 // set pSys=1, pNonSys=0
-(p9) mov r15=-1
(p15) ssm psr.i // restore psr.i
mov.m ar.fpsr=r17
stf8 [r8]=f1 // ensure pt_regs.r8 != 0 (see
handle_syscall_error)
+(p10) mov r8=-EINVAL
br.ret.sptk.many b7
END(ia64_syscall_setup)
diff -Nru a/arch/ia64/kernel/process.c b/arch/ia64/kernel/process.c
--- a/arch/ia64/kernel/process.c 2005-03-24 09:05:06 -08:00
+++ b/arch/ia64/kernel/process.c 2005-03-24 09:05:06 -08:00
@@ -485,7 +485,7 @@
return 1; /* f0-f31 are always valid so we always return 1 */
}
-asmlinkage long
+long
sys_execve (char *filename, char **argv, char **envp, struct pt_regs *regs)
{
int error;
-
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