Samuel Thibault, le Mon 25 Jun 2007 01:24:41 +0200, a écrit :
> Samuel Thibault, le Sun 24 Jun 2007 21:29:50 +0200, a écrit :
> > Samuel Thibault, le Sun 24 Jun 2007 17:51:25 +0200, a écrit :
> > > I've uploaded some experimental TLS-enabled hurd and libc packages for
> > > testing to
> > >
> > > http://dept-info.labri.fr/~thibault/debian-hurd/tls/
> >
> > They need the gdt user_ldt.c update, so make sure to have gnumach >=
> > 20070405.
>
> Note: though it works nicely on my box (I'm compiling glibc HEAD with it
> right now), it looks like it fails completely on others (Thomas and
> Olaf's at least), so please be careful :)
The problem I was having with Xen was when switch_ktss changes() the
descriptors, because in an interrupt context, gs is still loaded with
the user-level value. In january 2006, Jeroen made trap handlers load
kernel data segments in fs and gs, here is a patch to do the same on
interrupts (with it, I don't have issues on Xen any more).
Could people try TLS with a patched gnumach?
Note: there is still an issue with mach-defpager.
Samuel
Index: i386/i386/db_interface.c
===================================================================
RCS file: /cvsroot/hurd/gnumach/i386/i386/Attic/db_interface.c,v
retrieving revision 1.2.2.3.2.1
diff -u -p -r1.2.2.3.2.1 db_interface.c
--- i386/i386/db_interface.c 7 Jul 2007 17:21:19 -0000 1.2.2.3.2.1
+++ i386/i386/db_interface.c 8 Jul 2007 21:30:21 -0000
@@ -187,8 +187,6 @@ kdb_trap(
* instead of those at its call to KDB.
*/
struct int_regs {
- int gs;
- int fs;
int edi;
int esi;
int ebp;
@@ -227,8 +225,8 @@ kdb_kentry(
ddb_regs.edi = int_regs->edi;
ddb_regs.ds = is->ds;
ddb_regs.es = is->es;
- ddb_regs.fs = int_regs->fs;
- ddb_regs.gs = int_regs->gs;
+ ddb_regs.fs = is->fs;
+ ddb_regs.gs = is->gs;
cnpollc(TRUE);
db_task_trap(-1, 0, (ddb_regs.cs & 0x3) != 0);
@@ -250,8 +248,8 @@ kdb_kentry(
int_regs->edi = ddb_regs.edi;
is->ds = ddb_regs.ds & 0xffff;
is->es = ddb_regs.es & 0xffff;
- int_regs->fs = ddb_regs.fs & 0xffff;
- int_regs->gs = ddb_regs.gs & 0xffff;
+ is->fs = ddb_regs.fs & 0xffff;
+ is->gs = ddb_regs.gs & 0xffff;
}
#if NCPUS > 1
db_leave();
Index: i386/i386/kttd_interface.c
===================================================================
RCS file: /cvsroot/hurd/gnumach/i386/i386/Attic/kttd_interface.c,v
retrieving revision 1.2.2.3.2.1
diff -u -p -r1.2.2.3.2.1 kttd_interface.c
--- i386/i386/kttd_interface.c 7 Jul 2007 17:21:19 -0000 1.2.2.3.2.1
+++ i386/i386/kttd_interface.c 8 Jul 2007 21:30:21 -0000
@@ -491,8 +491,6 @@ boolean_t kttd_trap(int type, int code,
* instead of those at its call to KDB.
*/
struct int_regs {
- int gs;
- int fs;
int edi;
int esi;
int ebp;
@@ -541,8 +539,8 @@ kttd_netentry(int_regs)
kttd_regs.edi = int_regs->edi;
kttd_regs.ds = is->ds;
kttd_regs.es = is->es;
- kttd_regs.fs = int_regs->fs;
- kttd_regs.gs = int_regs->gs;
+ kttd_regs.fs = is->fs;
+ kttd_regs.gs = is->gs;
kttd_active++;
kttd_task_trap(-1, 0, (kttd_regs.cs & 0x3) != 0);
@@ -564,8 +562,8 @@ kttd_netentry(int_regs)
int_regs->edi = kttd_regs.edi;
is->ds = kttd_regs.ds & 0xffff;
is->es = kttd_regs.es & 0xffff;
- int_regs->fs = kttd_regs.fs & 0xffff;
- int_regs->gs = kttd_regs.gs & 0xffff;
+ is->fs = kttd_regs.fs & 0xffff;
+ is->gs = kttd_regs.gs & 0xffff;
if (kttd_run_status == RUNNING)
printf("kttd_netentry: %%%%% run_status already RUNNING!
%%%%%\n");
Index: i386/i386/locore.S
===================================================================
RCS file: /cvsroot/hurd/gnumach/i386/i386/locore.S,v
retrieving revision 1.6.2.7.2.3
diff -u -p -r1.6.2.7.2.3 locore.S
--- i386/i386/locore.S 7 May 2007 22:54:50 -0000 1.6.2.7.2.3
+++ i386/i386/locore.S 8 Jul 2007 21:30:21 -0000
@@ -646,9 +646,13 @@ ENTRY(all_intrs)
pushl %ds /* save segment registers */
pushl %es
+ pushl %fs
+ pushl %gs
mov %ss,%dx /* switch to kernel segments */
mov %dx,%ds
mov %dx,%es
+ mov %dx,%fs
+ mov %dx,%gs
CPU_NUMBER(%edx)
@@ -686,7 +690,9 @@ LEXT(return_to_iret) /* ( label for
kd
cmpl $0,CX(EXT(need_ast),%edx)
jnz ast_from_interrupt /* take it if so */
1:
- pop %es /* restore segment regs */
+ pop %gs /* restore segment regs */
+ pop %fs
+ pop %es
pop %ds
pop %edx
pop %ecx
@@ -704,11 +710,13 @@ _return_to_iret_i: /* ( label for
kdb_
/*
* Take an AST from an interrupt.
* On PCB stack.
- * sp-> es -> edx
- * ds -> ecx
- * edx -> eax
- * ecx -> trapno
- * eax -> code
+ * sp-> gs -> edx
+ * fs -> ecx
+ * es -> eax
+ * ds -> trapno
+ * edx -> code
+ * ecx
+ * eax
* eip
* cs
* efl
@@ -716,7 +724,9 @@ _return_to_iret_i: /* ( label for kdb_
* ss
*/
ast_from_interrupt:
- pop %es /* restore all registers ... */
+ pop %gs /* restore all registers ... */
+ pop %fs
+ pop %es
pop %ds
popl %edx
popl %ecx
@@ -731,6 +741,8 @@ ast_from_interrupt:
mov %ss,%dx /* switch to kernel segments */
mov %dx,%ds
mov %dx,%es
+ mov %dx,%fs
+ mov %dx,%gs
CPU_NUMBER(%edx)
TIME_TRAP_UENTRY
@@ -768,7 +780,9 @@ ast_from_interrupt:
* pointer to save area on old stack
* [ saved %ebx, if accurate timing ]
*
- * old stack: saved %es
+ * old stack: saved %gs
+ * saved %fs
+ * saved %es
* saved %ds
* saved %edx
* saved %ecx
@@ -820,14 +834,10 @@ kdb_from_iret:
pushl %ebp
pushl %esi
pushl %edi
- push %fs
- push %gs
pushl %esp /* pass regs */
call EXT(kdb_kentry) /* to kdb */
addl $4,%esp /* pop parameters */
- pop %gs /* restore registers */
- pop %fs
- popl %edi
+ popl %edi /* restore registers */
popl %esi
popl %ebp
#if STAT_TIME
@@ -906,14 +916,10 @@ ttd_from_iret:
pushl %ebp
pushl %esi
pushl %edi
- push %fs
- push %gs
pushl %esp /* pass regs */
call _kttd_netentry /* to kdb */
addl $4,%esp /* pop parameters */
- pop %gs /* restore registers */
- pop %fs
- popl %edi
+ popl %edi /* restore registers */
popl %esi
popl %ebp
#if STAT_TIME
Index: i386/i386/thread.h
===================================================================
RCS file: /cvsroot/hurd/gnumach/i386/i386/thread.h,v
retrieving revision 1.3.2.1.2.1
diff -u -p -r1.3.2.1.2.1 thread.h
--- i386/i386/thread.h 7 May 2007 22:54:50 -0000 1.3.2.1.2.1
+++ i386/i386/thread.h 8 Jul 2007 21:30:21 -0000
@@ -139,6 +139,8 @@ struct v86_assist_state {
*/
struct i386_interrupt_state {
+ int gs;
+ int fs;
int es;
int ds;
int edx;
Index: linux/src/include/asm-i386/irq.h
===================================================================
RCS file: /cvsroot/hurd/gnumach/linux/src/include/asm-i386/Attic/irq.h,v
retrieving revision 1.1
diff -u -p -r1.1 irq.h
--- linux/src/include/asm-i386/irq.h 26 Apr 1999 05:55:48 -0000 1.1
+++ linux/src/include/asm-i386/irq.h 8 Jul 2007 21:30:21 -0000
@@ -38,6 +38,7 @@ extern void enable_irq(unsigned int);
"movl $" STR(KERNEL_DS) ",%edx\n\t" \
"mov %dx,%ds\n\t" \
"mov %dx,%es\n\t" \
+ "mov %dx,%gs\n\t" \
"movl $" STR(USER_DS) ",%edx\n\t" \
"mov %dx,%fs\n\t" \
"movl $0,%edx\n\t" \
