From: Richard Henderson <rth@twiddle.net>
To: Matt Reppert <arashi@arashi.yi.org>
Cc: linux-kernel@vger.kernel.org
Subject: Re: 2.5.51 on Alpha oopses on mount
Date: Sun, 15 Dec 2002 10:57:22 -0800 [thread overview]
Message-ID: <20021215105722.A3831@twiddle.net> (raw)
In-Reply-To: <20021214123155.7383524c.arashi@arashi.yi.org>; from arashi@arashi.yi.org on Sat, Dec 14, 2002 at 12:31:55PM -0600
On Sat, Dec 14, 2002 at 12:31:55PM -0600, Matt Reppert wrote:
> >>PC; fffffc00004a5240 <__copy_user+100/1d4> <=====
> Trace; fffffc0000385920 <sys_mount+40/160>
This fault is expected and is _supposed_ to be handled by the
exception mechanism. Why this stopped working, I don't know.
For grins, see if the following helps. It's something that I
need for the shared-library modules anyway, and it eliminates
an extra variable from the problem.
r~
===== arch/alpha/kernel/traps.c 1.20 vs edited =====
--- 1.20/arch/alpha/kernel/traps.c Fri Nov 8 05:48:56 2002
+++ edited/arch/alpha/kernel/traps.c Sat Dec 14 11:24:11 2002
@@ -638,7 +638,7 @@
got_exception:
/* Ok, we caught the exception, but we don't want it. Is there
someone to pass it along to? */
- if ((fixup = search_exception_table(pc, regs.gp)) != 0) {
+ if ((fixup = search_exception_table(pc)) != 0) {
unsigned long newpc;
newpc = fixup_exception(una_reg, fixup, pc);
===== arch/alpha/lib/clear_user.S 1.1 vs edited =====
--- 1.1/arch/alpha/lib/clear_user.S Tue Feb 5 09:40:21 2002
+++ edited/arch/alpha/lib/clear_user.S Sat Dec 14 11:12:14 2002
@@ -29,7 +29,7 @@
#define EX(x,y...) \
99: x,##y; \
.section __ex_table,"a"; \
- .gprel32 99b; \
+ .long 99b - .; \
lda $31, $exception-99b($31); \
.previous
@@ -80,7 +80,6 @@
ret $31, ($28), 1 # .. e1 :
__do_clear_user:
- ldgp $29,0($27) # we do exceptions -- we need the gp.
and $6, 7, $4 # e0 : find dest misalignment
beq $0, $zerolength # .. e1 :
addq $0, $4, $1 # e0 : bias counter
===== arch/alpha/lib/copy_user.S 1.1 vs edited =====
--- 1.1/arch/alpha/lib/copy_user.S Tue Feb 5 09:40:21 2002
+++ edited/arch/alpha/lib/copy_user.S Sat Dec 14 11:13:48 2002
@@ -30,29 +30,28 @@
#define EXI(x,y...) \
99: x,##y; \
.section __ex_table,"a"; \
- .gprel32 99b; \
+ .long 99b - .; \
lda $31, $exitin-99b($31); \
.previous
#define EXO(x,y...) \
99: x,##y; \
.section __ex_table,"a"; \
- .gprel32 99b; \
+ .long 99b - .; \
lda $31, $exitout-99b($31); \
.previous
.set noat
- .align 3
+ .align 4
.globl __copy_user
.ent __copy_user
__copy_user:
- ldgp $29,0($27) # we do exceptions -- we need the gp.
- .prologue 1
+ .prologue 0
and $6,7,$3
beq $0,$35
beq $3,$36
subq $3,8,$3
- .align 5
+ .align 4
$37:
EXI( ldq_u $1,0($7) )
EXO( ldq_u $2,0($6) )
@@ -73,7 +72,7 @@
beq $1,$43
beq $4,$48
EXI( ldq_u $3,0($7) )
- .align 5
+ .align 4
$50:
EXI( ldq_u $2,8($7) )
subq $4,8,$4
@@ -88,7 +87,7 @@
bne $4,$50
$48:
beq $0,$41
- .align 5
+ .align 4
$57:
EXI( ldq_u $1,0($7) )
EXO( ldq_u $2,0($6) )
@@ -105,7 +104,7 @@
.align 4
$43:
beq $4,$65
- .align 5
+ .align 4
$66:
EXI( ldq $1,0($7) )
subq $4,8,$4
===== arch/alpha/lib/ev6-clear_user.S 1.1 vs edited =====
--- 1.1/arch/alpha/lib/ev6-clear_user.S Tue Feb 5 09:40:22 2002
+++ edited/arch/alpha/lib/ev6-clear_user.S Sat Dec 14 11:14:24 2002
@@ -47,7 +47,7 @@
#define EX(x,y...) \
99: x,##y; \
.section __ex_table,"a"; \
- .gprel32 99b; \
+ .long 99b - .; \
lda $31, $exception-99b($31); \
.previous
@@ -62,9 +62,6 @@
# Pipeline info : Slotting & Comments
__do_clear_user:
- ldgp $29,0($27) # we do exceptions -- we need the gp.
- # Macro instruction becomes ldah/lda
- # .. .. E E :
and $6, 7, $4 # .. E .. .. : find dest head misalignment
beq $0, $zerolength # U .. .. .. : U L U L
===== arch/alpha/lib/ev6-copy_user.S 1.1 vs edited =====
--- 1.1/arch/alpha/lib/ev6-copy_user.S Tue Feb 5 09:40:22 2002
+++ edited/arch/alpha/lib/ev6-copy_user.S Sat Dec 14 11:14:59 2002
@@ -41,14 +41,14 @@
#define EXI(x,y...) \
99: x,##y; \
.section __ex_table,"a"; \
- .gprel32 99b; \
+ .long 99b - .; \
lda $31, $exitin-99b($31); \
.previous
#define EXO(x,y...) \
99: x,##y; \
.section __ex_table,"a"; \
- .gprel32 99b; \
+ .long 99b - .; \
lda $31, $exitout-99b($31); \
.previous
@@ -58,10 +58,7 @@
.ent __copy_user
# Pipeline info: Slotting & Comments
__copy_user:
- ldgp $29,0($27) # we do exceptions -- we need the gp.
- # Macro instruction becomes ldah/lda
- # .. .. E E
- .prologue 1
+ .prologue 0
subq $0, 32, $1 # .. E .. .. : Is this going to be a small copy?
beq $0, $zerolength # U .. .. .. : U L U L
===== arch/alpha/lib/ev6-strncpy_from_user.S 1.2 vs edited =====
--- 1.2/arch/alpha/lib/ev6-strncpy_from_user.S Thu Aug 8 12:28:01 2002
+++ edited/arch/alpha/lib/ev6-strncpy_from_user.S Sat Dec 14 11:16:49 2002
@@ -34,7 +34,7 @@
#define EX(x,y...) \
99: x,##y; \
.section __ex_table,"a"; \
- .gprel32 99b; \
+ .long 99b - .; \
lda $31, $exception-99b($0); \
.previous
@@ -46,11 +46,10 @@
.globl __strncpy_from_user
.ent __strncpy_from_user
.frame $30, 0, $26
- .prologue 1
+ .prologue 0
.align 4
__strncpy_from_user:
- ldgp $29, 0($27) # E E : becomes 2 instructions (for exceptions)
and a0, 7, t3 # E : find dest misalignment
beq a2, $zerolength # U :
===== arch/alpha/lib/ev67-strlen_user.S 1.2 vs edited =====
--- 1.2/arch/alpha/lib/ev67-strlen_user.S Thu Aug 8 12:28:01 2002
+++ edited/arch/alpha/lib/ev67-strlen_user.S Sat Dec 14 11:15:49 2002
@@ -30,7 +30,7 @@
#define EX(x,y...) \
99: x,##y; \
.section __ex_table,"a"; \
- .gprel32 99b; \
+ .long 99b - .; \
lda v0, $exception-99b(zero); \
.previous
@@ -56,9 +56,7 @@
.align 4
__strnlen_user:
- ldgp $29,0($27) # E E : we do exceptions -- we need the gp.
- /* Decomposes into lda/ldah */
- .prologue 1
+ .prologue 0
EX( ldq_u t0, 0(a0) ) # L : load first quadword (a0 may be misaligned)
lda t1, -1(zero) # E :
===== arch/alpha/lib/strlen_user.S 1.2 vs edited =====
--- 1.2/arch/alpha/lib/strlen_user.S Thu Aug 8 12:28:01 2002
+++ edited/arch/alpha/lib/strlen_user.S Sat Dec 14 11:16:04 2002
@@ -19,7 +19,7 @@
#define EX(x,y...) \
99: x,##y; \
.section __ex_table,"a"; \
- .gprel32 99b; \
+ .long 99b - .; \
lda v0, $exception-99b(zero); \
.previous
@@ -42,8 +42,7 @@
.align 3
__strnlen_user:
- ldgp $29,0($27) # we do exceptions -- we need the gp.
- .prologue 1
+ .prologue 0
EX( ldq_u t0, 0(a0) ) # load first quadword (a0 may be misaligned)
lda t1, -1(zero)
===== arch/alpha/lib/strncpy_from_user.S 1.2 vs edited =====
--- 1.2/arch/alpha/lib/strncpy_from_user.S Thu Aug 8 12:28:01 2002
+++ edited/arch/alpha/lib/strncpy_from_user.S Sat Dec 14 11:17:01 2002
@@ -19,7 +19,7 @@
#define EX(x,y...) \
99: x,##y; \
.section __ex_table,"a"; \
- .gprel32 99b; \
+ .long 99b - .; \
lda $31, $exception-99b($0); \
.previous
@@ -31,7 +31,7 @@
.globl __strncpy_from_user
.ent __strncpy_from_user
.frame $30, 0, $26
- .prologue 1
+ .prologue 0
.align 3
$aligned:
@@ -100,8 +100,6 @@
/*** The Function Entry Point ***/
.align 3
__strncpy_from_user:
- ldgp $29, 0($27) # we do exceptions -- we need the gp.
-
mov a0, v0 # save the string start
beq a2, $zerolength
===== arch/alpha/mm/extable.c 1.2 vs edited =====
--- 1.2/arch/alpha/mm/extable.c Mon Feb 4 23:40:23 2002
+++ edited/arch/alpha/mm/extable.c Sat Dec 14 11:23:06 2002
@@ -12,21 +12,17 @@
static inline unsigned
search_one_table(const struct exception_table_entry *first,
const struct exception_table_entry *last,
- signed long value)
+ unsigned long value)
{
- /* Abort early if the search value is out of range. */
- if (value != (signed int)value)
- return 0;
-
while (first <= last) {
const struct exception_table_entry *mid;
- long diff;
+ unsigned long mid_value;
mid = (last - first) / 2 + first;
- diff = mid->insn - value;
- if (diff == 0)
+ mid_value = (unsigned long)&mid->insn + mid->insn;
+ if (mid_value == value)
return mid->fixup.unit;
- else if (diff < 0)
+ else if (mid_value < value)
first = mid+1;
else
last = mid-1;
@@ -34,48 +30,13 @@
return 0;
}
-register unsigned long gp __asm__("$29");
-
-static unsigned
-search_exception_table_without_gp(unsigned long addr)
-{
- unsigned ret;
-
-#ifndef CONFIG_MODULES
- /* There is only the kernel to search. */
- ret = search_one_table(__start___ex_table, __stop___ex_table - 1,
- addr - gp);
-#else
- extern spinlock_t modlist_lock;
- unsigned long flags;
- /* The kernel is the last "module" -- no need to treat it special. */
- struct module *mp;
-
- ret = 0;
- spin_lock_irqsave(&modlist_lock, flags);
- for (mp = module_list; mp ; mp = mp->next) {
- if (!mp->ex_table_start || !(mp->flags&(MOD_RUNNING|MOD_INITIALIZING)))
- continue;
- ret = search_one_table(mp->ex_table_start,
- mp->ex_table_end - 1, addr - mp->gp);
- if (ret)
- break;
- }
- spin_unlock_irqrestore(&modlist_lock, flags);
-#endif
-
- return ret;
-}
-
unsigned
-search_exception_table(unsigned long addr, unsigned long exc_gp)
+search_exception_table(unsigned long addr)
{
unsigned ret;
#ifndef CONFIG_MODULES
- ret = search_one_table(__start___ex_table, __stop___ex_table - 1,
- addr - exc_gp);
- if (ret) return ret;
+ ret = search_one_table(__start___ex_table, __stop___ex_table-1, addr);
#else
extern spinlock_t modlist_lock;
unsigned long flags;
@@ -88,25 +49,12 @@
if (!mp->ex_table_start || !(mp->flags&(MOD_RUNNING|MOD_INITIALIZING)))
continue;
ret = search_one_table(mp->ex_table_start,
- mp->ex_table_end - 1, addr - exc_gp);
+ mp->ex_table_end - 1, addr);
if (ret)
break;
}
spin_unlock_irqrestore(&modlist_lock, flags);
- if (ret) return ret;
#endif
- /*
- * The search failed with the exception gp. To be safe, try the
- * old method before giving up.
- */
- ret = search_exception_table_without_gp(addr);
- if (ret) {
- printk(KERN_ALERT "%s: [%lx] EX_TABLE search fail with"
- "exc frame GP, success with raw GP\n",
- current->comm, addr);
- return ret;
- }
-
- return 0;
+ return ret;
}
===== arch/alpha/mm/fault.c 1.8 vs edited =====
--- 1.8/arch/alpha/mm/fault.c Wed Oct 30 10:42:09 2002
+++ edited/arch/alpha/mm/fault.c Sat Dec 14 11:23:31 2002
@@ -176,7 +176,7 @@
no_context:
/* Are we prepared to handle this fault as an exception? */
- if ((fixup = search_exception_table(regs->pc, regs->gp)) != 0) {
+ if ((fixup = search_exception_table(regs->pc)) != 0) {
unsigned long newpc;
newpc = fixup_exception(dpf_reg, fixup, regs->pc);
regs->pc = newpc;
===== include/asm-alpha/uaccess.h 1.2 vs edited =====
--- 1.2/include/asm-alpha/uaccess.h Mon Feb 11 05:42:53 2002
+++ edited/include/asm-alpha/uaccess.h Sat Dec 14 11:18:49 2002
@@ -126,7 +126,7 @@
__asm__("1: ldq %0,%2\n" \
"2:\n" \
".section __ex_table,\"a\"\n" \
- " .gprel32 1b\n" \
+ " .long 1b - .\n" \
" lda %0, 2b-1b(%1)\n" \
".previous" \
: "=r"(__gu_val), "=r"(__gu_err) \
@@ -136,7 +136,7 @@
__asm__("1: ldl %0,%2\n" \
"2:\n" \
".section __ex_table,\"a\"\n" \
- " .gprel32 1b\n" \
+ " .long 1b - .\n" \
" lda %0, 2b-1b(%1)\n" \
".previous" \
: "=r"(__gu_val), "=r"(__gu_err) \
@@ -149,7 +149,7 @@
__asm__("1: ldwu %0,%2\n" \
"2:\n" \
".section __ex_table,\"a\"\n" \
- " .gprel32 1b\n" \
+ " .long 1b - .\n" \
" lda %0, 2b-1b(%1)\n" \
".previous" \
: "=r"(__gu_val), "=r"(__gu_err) \
@@ -159,7 +159,7 @@
__asm__("1: ldbu %0,%2\n" \
"2:\n" \
".section __ex_table,\"a\"\n" \
- " .gprel32 1b\n" \
+ " .long 1b - .\n" \
" lda %0, 2b-1b(%1)\n" \
".previous" \
: "=r"(__gu_val), "=r"(__gu_err) \
@@ -178,10 +178,10 @@
" or %0,%1,%0\n" \
"3:\n" \
".section __ex_table,\"a\"\n" \
- " .gprel32 1b\n" \
+ " .long 1b - .\n" \
" lda %0, 3b-1b(%2)\n" \
- " .gprel32 2b\n" \
- " lda %0, 2b-1b(%2)\n" \
+ " .long 2b - .\n" \
+ " lda %0, 3b-2b(%2)\n" \
".previous" \
: "=&r"(__gu_val), "=&r"(__gu_tmp), "=r"(__gu_err) \
: "r"(addr), "2"(__gu_err)); \
@@ -192,7 +192,7 @@
" extbl %0,%2,%0\n" \
"2:\n" \
".section __ex_table,\"a\"\n" \
- " .gprel32 1b\n" \
+ " .long 1b - .\n" \
" lda %0, 2b-1b(%1)\n" \
".previous" \
: "=&r"(__gu_val), "=r"(__gu_err) \
@@ -240,7 +240,7 @@
__asm__ __volatile__("1: stq %r2,%1\n" \
"2:\n" \
".section __ex_table,\"a\"\n" \
- " .gprel32 1b\n" \
+ " .long 1b - .\n" \
" lda $31,2b-1b(%0)\n" \
".previous" \
: "=r"(__pu_err) \
@@ -250,7 +250,7 @@
__asm__ __volatile__("1: stl %r2,%1\n" \
"2:\n" \
".section __ex_table,\"a\"\n" \
- " .gprel32 1b\n" \
+ " .long 1b - .\n" \
" lda $31,2b-1b(%0)\n" \
".previous" \
: "=r"(__pu_err) \
@@ -263,7 +263,7 @@
__asm__ __volatile__("1: stw %r2,%1\n" \
"2:\n" \
".section __ex_table,\"a\"\n" \
- " .gprel32 1b\n" \
+ " .long 1b - .\n" \
" lda $31,2b-1b(%0)\n" \
".previous" \
: "=r"(__pu_err) \
@@ -273,7 +273,7 @@
__asm__ __volatile__("1: stb %r2,%1\n" \
"2:\n" \
".section __ex_table,\"a\"\n" \
- " .gprel32 1b\n" \
+ " .long 1b - .\n" \
" lda $31,2b-1b(%0)\n" \
".previous" \
: "=r"(__pu_err) \
@@ -298,13 +298,13 @@
"4: stq_u %1,0(%5)\n" \
"5:\n" \
".section __ex_table,\"a\"\n" \
- " .gprel32 1b\n" \
+ " .long 1b - .\n" \
" lda $31, 5b-1b(%0)\n" \
- " .gprel32 2b\n" \
+ " .long 2b - .\n" \
" lda $31, 5b-2b(%0)\n" \
- " .gprel32 3b\n" \
+ " .long 3b - .\n" \
" lda $31, 5b-3b(%0)\n" \
- " .gprel32 4b\n" \
+ " .long 4b - .\n" \
" lda $31, 5b-4b(%0)\n" \
".previous" \
: "=r"(__pu_err), "=&r"(__pu_tmp1), \
@@ -324,9 +324,9 @@
"2: stq_u %1,0(%4)\n" \
"3:\n" \
".section __ex_table,\"a\"\n" \
- " .gprel32 1b\n" \
+ " .long 1b - .\n" \
" lda $31, 3b-1b(%0)\n" \
- " .gprel32 2b\n" \
+ " .long 2b - .\n" \
" lda $31, 3b-2b(%0)\n" \
".previous" \
: "=r"(__pu_err), \
@@ -356,7 +356,7 @@
register long __cu_len __asm__("$0") = len;
__asm__ __volatile__(
- "jsr $28,(%3),__copy_user\n\tldgp $29,0($28)"
+ "jsr $28,(%3),__copy_user"
: "=r" (__cu_len), "=r" (__cu_from), "=r" (__cu_to), "=r"(pv)
: "0" (__cu_len), "1" (__cu_from), "2" (__cu_to), "3"(pv)
: "$1","$2","$3","$4","$5","$28","memory");
@@ -373,7 +373,7 @@
register const void * __cu_from __asm__("$7") = from;
register long __cu_len __asm__("$0") = len;
__asm__ __volatile__(
- "jsr $28,(%3),__copy_user\n\tldgp $29,0($28)"
+ "jsr $28,(%3),__copy_user"
: "=r"(__cu_len), "=r"(__cu_from), "=r"(__cu_to),
"=r" (pv)
: "0" (__cu_len), "1" (__cu_from), "2" (__cu_to),
@@ -413,7 +413,7 @@
register void * __cl_to __asm__("$6") = to;
register long __cl_len __asm__("$0") = len;
__asm__ __volatile__(
- "jsr $28,(%2),__do_clear_user\n\tldgp $29,0($28)"
+ "jsr $28,(%2),__do_clear_user"
: "=r"(__cl_len), "=r"(__cl_to), "=r"(pv)
: "0"(__cl_len), "1"(__cl_to), "2"(pv)
: "$1","$2","$3","$4","$5","$28","memory");
@@ -428,7 +428,7 @@
register void * __cl_to __asm__("$6") = to;
register long __cl_len __asm__("$0") = len;
__asm__ __volatile__(
- "jsr $28,(%2),__do_clear_user\n\tldgp $29,0($28)"
+ "jsr $28,(%2),__do_clear_user"
: "=r"(__cl_len), "=r"(__cl_to), "=r"(pv)
: "0"(__cl_len), "1"(__cl_to), "2"(pv)
: "$1","$2","$3","$4","$5","$28","memory");
@@ -471,7 +471,7 @@
/*
* About the exception table:
*
- * - insn is a 32-bit offset off of the kernel's or module's gp.
+ * - insn is a 32-bit pc-relative offset from the faulting insn.
* - nextinsn is a 16-bit offset off of the faulting instruction
* (not off of the *next* instruction as branches are).
* - errreg is the register in which to place -EFAULT.
@@ -502,7 +502,7 @@
};
/* Returns 0 if exception not found and fixup.unit otherwise. */
-extern unsigned search_exception_table(unsigned long, unsigned long);
+extern unsigned search_exception_table(unsigned long);
/* Returns the new pc */
#define fixup_exception(map_reg, fixup_unit, pc) \
next prev parent reply other threads:[~2002-12-15 18:51 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2002-12-14 18:31 2.5.51 on Alpha oopses on mount Matt Reppert
2002-12-15 18:57 ` Richard Henderson [this message]
2002-12-15 21:01 ` Matt Reppert
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