2002-09-25 03:27:52

by Rusty Russell

[permalink] [raw]
Subject: [PATCH] Module rewrite 18/20: exception table arch cleanup

Name: extable cleanup
Author: Rusty Russell
Status: Experimental
Depends: Module/fini.patch.gz

D: This patch combines the common exception table searching
D: functionality for various architectures, to avoid unneccessary (and
D: currently buggy) duplication, and so that the exception table list
D: and lock can be kept private to module.c.

diff -urpN --exclude TAGS -X /home/rusty/devel/kernel/kernel-patches/current-dontdiff --minimal .17925-linux-2.5.38/arch/i386/kernel/traps.c .17925-linux-2.5.38.updated/arch/i386/kernel/traps.c
--- .17925-linux-2.5.38/arch/i386/kernel/traps.c 2002-09-25 02:07:36.000000000 +1000
+++ .17925-linux-2.5.38.updated/arch/i386/kernel/traps.c 2002-09-25 02:08:05.000000000 +1000
@@ -329,7 +329,7 @@ static void inline do_trap(int trapnr, i
}

kernel_trap: {
- unsigned long fixup;
+ const struct exception_table_entry *fixup;
#ifdef CONFIG_PNPBIOS
if (unlikely((regs->xcs | 8) == 0x88)) /* 0x80 or 0x88 */
{
@@ -345,9 +345,9 @@ static void inline do_trap(int trapnr, i
}
#endif

- fixup = search_exception_table(regs->eip);
+ fixup = search_exception_tables(regs->eip);
if (fixup)
- regs->eip = fixup;
+ regs->eip = fixup->fixup;
else
die(str, regs, error_code);
return;
@@ -426,10 +426,10 @@ gp_in_vm86:

gp_in_kernel:
{
- unsigned long fixup;
- fixup = search_exception_table(regs->eip);
+ const struct exception_table_entry *fixup;
+ fixup = search_exception_tables(regs->eip);
if (fixup) {
- regs->eip = fixup;
+ regs->eip = fixup->fixup;
return;
}
die("general protection fault", regs, error_code);
diff -urpN --exclude TAGS -X /home/rusty/devel/kernel/kernel-patches/current-dontdiff --minimal .17925-linux-2.5.38/arch/i386/mm/extable.c .17925-linux-2.5.38.updated/arch/i386/mm/extable.c
--- .17925-linux-2.5.38/arch/i386/mm/extable.c 2002-09-25 02:07:36.000000000 +1000
+++ .17925-linux-2.5.38.updated/arch/i386/mm/extable.c 2002-09-25 02:09:40.000000000 +1000
@@ -7,13 +7,11 @@
#include <linux/spinlock.h>
#include <asm/uaccess.h>

-extern const struct exception_table_entry __start___ex_table[];
-extern const struct exception_table_entry __stop___ex_table[];
-
-static inline unsigned long
-search_one_table(const struct exception_table_entry *first,
- const struct exception_table_entry *last,
- unsigned long value)
+/* Simple binary search */
+const struct exception_table_entry *
+search_extable(const struct exception_table_entry *first,
+ const struct exception_table_entry *last,
+ unsigned long value)
{
while (first <= last) {
const struct exception_table_entry *mid;
@@ -22,43 +20,11 @@ search_one_table(const struct exception_
mid = (last - first) / 2 + first;
diff = mid->insn - value;
if (diff == 0)
- return mid->fixup;
+ return mid;
else if (diff < 0)
first = mid+1;
else
last = mid-1;
}
- return 0;
-}
-
-extern spinlock_t modlist_lock;
-
-unsigned long
-search_exception_table(unsigned long addr)
-{
- unsigned long ret = 0;
-
-#ifndef CONFIG_MODULES
- /* There is only the kernel to search. */
- ret = search_one_table(__start___ex_table, __stop___ex_table-1, addr);
- return ret;
-#else
- unsigned long flags;
- struct list_head *i;
-
- /* The kernel is the last "module" -- no need to treat it special. */
- spin_lock_irqsave(&modlist_lock, flags);
- list_for_each(i, &extables) {
- struct exception_table *ex
- = list_entry(i, struct exception_table, list);
- if (ex->num_entries == 0)
- continue;
- ret = search_one_table(ex->entry,
- ex->entry + ex->num_entries - 1, addr);
- if (ret)
- break;
- }
- spin_unlock_irqrestore(&modlist_lock, flags);
- return ret;
-#endif
+ return NULL;
}
diff -urpN --exclude TAGS -X /home/rusty/devel/kernel/kernel-patches/current-dontdiff --minimal .17925-linux-2.5.38/arch/i386/mm/fault.c .17925-linux-2.5.38.updated/arch/i386/mm/fault.c
--- .17925-linux-2.5.38/arch/i386/mm/fault.c 2002-08-28 09:29:40.000000000 +1000
+++ .17925-linux-2.5.38.updated/arch/i386/mm/fault.c 2002-09-25 02:08:05.000000000 +1000
@@ -19,6 +19,7 @@
#include <linux/init.h>
#include <linux/tty.h>
#include <linux/vt_kern.h> /* For unblank_screen() */
+#include <linux/module.h>

#include <asm/system.h>
#include <asm/uaccess.h>
@@ -148,7 +149,7 @@ asmlinkage void do_page_fault(struct pt_
struct vm_area_struct * vma;
unsigned long address;
unsigned long page;
- unsigned long fixup;
+ const struct exception_table_entry *fixup;
int write;
siginfo_t info;

@@ -304,8 +305,8 @@ bad_area:

no_context:
/* Are we prepared to handle this kernel fault? */
- if ((fixup = search_exception_table(regs->eip)) != 0) {
- regs->eip = fixup;
+ if ((fixup = search_exception_tables(regs->eip)) != NULL) {
+ regs->eip = fixup->fixup;
return;
}

diff -urpN --exclude TAGS -X /home/rusty/devel/kernel/kernel-patches/current-dontdiff --minimal .17925-linux-2.5.38/arch/ppc/kernel/traps.c .17925-linux-2.5.38.updated/arch/ppc/kernel/traps.c
--- .17925-linux-2.5.38/arch/ppc/kernel/traps.c 2002-09-21 13:55:09.000000000 +1000
+++ .17925-linux-2.5.38.updated/arch/ppc/kernel/traps.c 2002-09-25 02:08:05.000000000 +1000
@@ -29,6 +29,7 @@
#include <linux/interrupt.h>
#include <linux/config.h>
#include <linux/init.h>
+#include <linux/module.h>

#include <asm/pgtable.h>
#include <asm/uaccess.h>
@@ -115,7 +116,7 @@ void
MachineCheckException(struct pt_regs *regs)
{
#ifdef CONFIG_ALL_PPC
- unsigned long fixup;
+ const struct exception_table_entry *entry;
#endif /* CONFIG_ALL_PPC */
unsigned long msr = regs->msr;

@@ -148,7 +149,7 @@ MachineCheckException(struct pt_regs *re
* -- paulus.
*/
if (((msr & 0xffff0000) == 0 || (msr & (0x80000 | 0x40000)))
- && (fixup = search_exception_table(regs->nip)) != 0) {
+ && (entry = search_exception_tables(regs->nip)) != NULL) {
/*
* Check that it's a sync instruction, or somewhere
* in the twi; isync; nop sequence that inb/inw/inl uses.
diff -urpN --exclude TAGS -X /home/rusty/devel/kernel/kernel-patches/current-dontdiff --minimal .17925-linux-2.5.38/arch/ppc/mm/extable.c .17925-linux-2.5.38.updated/arch/ppc/mm/extable.c
--- .17925-linux-2.5.38/arch/ppc/mm/extable.c 2002-09-21 13:55:09.000000000 +1000
+++ .17925-linux-2.5.38.updated/arch/ppc/mm/extable.c 2002-09-25 02:08:05.000000000 +1000
@@ -6,6 +6,7 @@

#include <linux/config.h>
#include <linux/module.h>
+#include <linux/init.h>
#include <asm/uaccess.h>

extern struct exception_table_entry __start___ex_table[];
@@ -40,16 +41,17 @@ sort_ex_table(struct exception_table_ent
}
}

-void
+void __init
sort_exception_table(void)
{
sort_ex_table(__start___ex_table, __stop___ex_table);
}

-static inline unsigned long
-search_one_table(const struct exception_table_entry *first,
- const struct exception_table_entry *last,
- unsigned long value)
+/* Simple binary search */
+const struct exception_table_entry *
+search_extable(const struct exception_table_entry *first,
+ const struct exception_table_entry *last,
+ unsigned long value)
{
while (first <= last) {
const struct exception_table_entry *mid;
@@ -58,36 +60,11 @@ search_one_table(const struct exception_
mid = (last - first) / 2 + first;
diff = mid->insn - value;
if (diff == 0)
- return mid->fixup;
+ return mid;
else if (diff < 0)
first = mid+1;
else
last = mid-1;
}
- return 0;
-}
-
-unsigned long
-search_exception_table(unsigned long addr)
-{
- unsigned long ret;
-
-#ifndef CONFIG_MODULES
- /* There is only the kernel to search. */
- ret = search_one_table(__start___ex_table, __stop___ex_table-1, addr);
- if (ret) return ret;
-#else
- /* The kernel is the last "module" -- no need to treat it special. */
- struct module *mp;
- for (mp = module_list; mp != NULL; mp = mp->next) {
- if (mp->ex_table_start == NULL)
- continue;
- ret = search_one_table(mp->ex_table_start,
- mp->ex_table_end - 1, addr);
- if (ret)
- return ret;
- }
-#endif
-
- return 0;
+ return NULL;
}
diff -urpN --exclude TAGS -X /home/rusty/devel/kernel/kernel-patches/current-dontdiff --minimal .17925-linux-2.5.38/arch/ppc/mm/fault.c .17925-linux-2.5.38.updated/arch/ppc/mm/fault.c
--- .17925-linux-2.5.38/arch/ppc/mm/fault.c 2002-09-21 13:55:09.000000000 +1000
+++ .17925-linux-2.5.38.updated/arch/ppc/mm/fault.c 2002-09-25 02:08:05.000000000 +1000
@@ -27,6 +27,7 @@
#include <linux/mm.h>
#include <linux/interrupt.h>
#include <linux/highmem.h>
+#include <linux/module.h>

#include <asm/page.h>
#include <asm/pgtable.h>
@@ -263,12 +264,11 @@ void
bad_page_fault(struct pt_regs *regs, unsigned long address, int sig)
{
extern void die(const char *,struct pt_regs *,long);
-
- unsigned long fixup;
+ const struct exception_table_entry *entry;

/* Are we prepared to handle this fault? */
- if ((fixup = search_exception_table(regs->nip)) != 0) {
- regs->nip = fixup;
+ if ((entry = search_exception_tables(regs->nip)) != NULL) {
+ regs->nip = entry->fixup;
return;
}

diff -urpN --exclude TAGS -X /home/rusty/devel/kernel/kernel-patches/current-dontdiff --minimal .17925-linux-2.5.38/arch/sparc64/kernel/traps.c .17925-linux-2.5.38.updated/arch/sparc64/kernel/traps.c
--- .17925-linux-2.5.38/arch/sparc64/kernel/traps.c 2002-09-21 13:55:12.000000000 +1000
+++ .17925-linux-2.5.38.updated/arch/sparc64/kernel/traps.c 2002-09-25 02:08:05.000000000 +1000
@@ -149,17 +149,17 @@ void data_access_exception (struct pt_re

if (regs->tstate & TSTATE_PRIV) {
/* Test if this comes from uaccess places. */
- unsigned long fixup, g2;
+ const struct exception_table_entry *entry;
+ unsigned long g2 = regs->u_regs[UREG_G2];

- g2 = regs->u_regs[UREG_G2];
- if ((fixup = search_exception_table (regs->tpc, &g2))) {
+ if ((entry = search_extables_range(regs->tpc, &g2))) {
/* Ouch, somebody is trying ugly VM hole tricks on us... */
#ifdef DEBUG_EXCEPTIONS
printk("Exception: PC<%016lx> faddr<UNKNOWN>\n", regs->tpc);
printk("EX_TABLE: insn<%016lx> fixup<%016lx> "
- "g2<%016lx>\n", regs->tpc, fixup, g2);
+ "g2<%016lx>\n", regs->tpc, entry->fixup, g2);
#endif
- regs->tpc = fixup;
+ regs->tpc = entry->fixup;
regs->tnpc = regs->tpc + 4;
regs->u_regs[UREG_G2] = g2;
return;
@@ -1370,7 +1370,7 @@ void cheetah_deferred_handler(struct pt_
recoverable = 1;
} else {
unsigned long g2 = regs->u_regs[UREG_G2];
- unsigned long fixup = search_exception_table(regs->tpc, &g2);
+ unsigned long fixup = search_extables_range(regs->tpc, &g2);

if (fixup != 0UL) {
/* OK, kernel access to userspace. */
@@ -1390,8 +1390,8 @@ void cheetah_deferred_handler(struct pt_
/* Only perform fixup if we still have a
* recoverable condition.
*/
- if (fixup != 0UL && recoverable) {
- regs->tpc = fixup;
+ if (entry && recoverable) {
+ regs->tpc = entry->fixup;
regs->tnpc = regs->tpc + 4;
regs->u_regs[UREG_G2] = g2;
}
diff -urpN --exclude TAGS -X /home/rusty/devel/kernel/kernel-patches/current-dontdiff --minimal .17925-linux-2.5.38/arch/sparc64/kernel/unaligned.c .17925-linux-2.5.38.updated/arch/sparc64/kernel/unaligned.c
--- .17925-linux-2.5.38/arch/sparc64/kernel/unaligned.c 2002-08-11 15:31:33.000000000 +1000
+++ .17925-linux-2.5.38.updated/arch/sparc64/kernel/unaligned.c 2002-09-25 02:08:05.000000000 +1000
@@ -10,6 +10,7 @@
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/mm.h>
+#include <linux/module.h>
#include <asm/asi.h>
#include <asm/ptrace.h>
#include <asm/pstate.h>
diff -urpN --exclude TAGS -X /home/rusty/devel/kernel/kernel-patches/current-dontdiff --minimal .17925-linux-2.5.38/arch/sparc64/mm/extable.c .17925-linux-2.5.38.updated/arch/sparc64/mm/extable.c
--- .17925-linux-2.5.38/arch/sparc64/mm/extable.c 2002-02-20 17:55:22.000000000 +1100
+++ .17925-linux-2.5.38.updated/arch/sparc64/mm/extable.c 2002-09-25 02:08:05.000000000 +1000
@@ -9,10 +9,11 @@
extern const struct exception_table_entry __start___ex_table[];
extern const struct exception_table_entry __stop___ex_table[];

-static unsigned long
-search_one_table(const struct exception_table_entry *start,
- const struct exception_table_entry *end,
- unsigned long value, unsigned long *g2)
+/* Caller knows they are in a range if ret->fixup == 0 */
+const struct exception_table_entry *
+search_extable(const struct exception_table_entry *start,
+ const struct exception_table_entry *last,
+ unsigned long value)
{
const struct exception_table_entry *walk;

@@ -38,7 +39,7 @@ search_one_table(const struct exception_
}

if (walk->insn == value)
- return walk->fixup;
+ return walk;
}

/* 2. Try to find a range match. */
@@ -46,43 +47,28 @@ search_one_table(const struct exception_
if (walk->fixup)
continue;

- if (walk[0].insn <= value &&
- walk[1].insn > value) {
- *g2 = (value - walk[0].insn) / 4;
- return walk[1].fixup;
- }
+ if (walk[0].insn <= value && walk[1].insn > value)
+ return walk;
walk++;
}

- return 0;
+ return NULL;
}

-extern spinlock_t modlist_lock;
-
-unsigned long
-search_exception_table(unsigned long addr, unsigned long *g2)
+/* Special exable search, which handles ranges. Returns fixup */
+unsigned long search_extables_range(unsigned long addr, unsigned long *g2)
{
- unsigned long ret = 0, flags;
+ const struct exception_table_entry *entry;

-#ifndef CONFIG_MODULES
- /* There is only the kernel to search. */
- ret = search_one_table(__start___ex_table,
- __stop___ex_table-1, addr, g2);
- return ret;
-#else
- /* The kernel is the last "module" -- no need to treat it special. */
- struct module *mp;
+ entry = search_exception_tables(addr);
+ if (!entry)
+ return 0;

- spin_lock_irqsave(&modlist_lock, flags);
- for (mp = module_list; mp != NULL; mp = mp->next) {
- if (mp->ex_table_start == NULL || !(mp->flags & (MOD_RUNNING | MOD_INITIALIZING)))
- continue;
- ret = search_one_table(mp->ex_table_start,
- mp->ex_table_end-1, addr, g2);
- if (ret)
- break;
+ /* Inside range? Fix g2 and return correct fixup */
+ if (!entry->fixup) {
+ *g2 = (addr - entry->insn) / 4;
+ return (entry + 1)->fixup;
}
- spin_unlock_irqrestore(&modlist_lock, flags);
- return ret;
-#endif
+
+ return entry->fixup;
}
diff -urpN --exclude TAGS -X /home/rusty/devel/kernel/kernel-patches/current-dontdiff --minimal .17925-linux-2.5.38/arch/sparc64/mm/fault.c .17925-linux-2.5.38.updated/arch/sparc64/mm/fault.c
--- .17925-linux-2.5.38/arch/sparc64/mm/fault.c 2002-09-21 13:55:12.000000000 +1000
+++ .17925-linux-2.5.38.updated/arch/sparc64/mm/fault.c 2002-09-25 02:08:05.000000000 +1000
@@ -14,6 +14,7 @@
#include <linux/mman.h>
#include <linux/signal.h>
#include <linux/mm.h>
+#include <linux/module.h>
#include <linux/smp_lock.h>
#include <linux/init.h>
#include <linux/interrupt.h>
@@ -282,10 +283,10 @@ static void do_kernel_fault(struct pt_re
else
asi = (insn >> 5);
}
-
+
/* Look in asi.h: All _S asis have LS bit set */
if ((asi & 0x1) &&
- (fixup = search_exception_table (regs->tpc, &g2))) {
+ (fizup = search_extables_range(regs->tpc, &g2))) {
regs->tpc = fixup;
regs->tnpc = regs->tpc + 4;
regs->u_regs[UREG_G2] = g2;
diff -urpN --exclude TAGS -X /home/rusty/devel/kernel/kernel-patches/current-dontdiff --minimal .17925-linux-2.5.38/include/asm-i386/uaccess.h .17925-linux-2.5.38.updated/include/asm-i386/uaccess.h
--- .17925-linux-2.5.38/include/asm-i386/uaccess.h 2002-05-24 15:20:31.000000000 +1000
+++ .17925-linux-2.5.38.updated/include/asm-i386/uaccess.h 2002-09-25 02:08:05.000000000 +1000
@@ -84,10 +84,6 @@ struct exception_table_entry
unsigned long insn, fixup;
};

-/* Returns 0 if exception not found and fixup otherwise. */
-extern unsigned long search_exception_table(unsigned long);
-
-
/*
* These are the main single-value transfer routines. They automatically
* use the right size if we just have the right pointer type.
diff -urpN --exclude TAGS -X /home/rusty/devel/kernel/kernel-patches/current-dontdiff --minimal .17925-linux-2.5.38/include/asm-ppc/uaccess.h .17925-linux-2.5.38.updated/include/asm-ppc/uaccess.h
--- .17925-linux-2.5.38/include/asm-ppc/uaccess.h 2002-09-21 13:55:18.000000000 +1000
+++ .17925-linux-2.5.38.updated/include/asm-ppc/uaccess.h 2002-09-25 02:08:05.000000000 +1000
@@ -56,8 +56,6 @@ struct exception_table_entry
unsigned long insn, fixup;
};

-/* Returns 0 if exception not found and fixup otherwise. */
-extern unsigned long search_exception_table(unsigned long);
extern void sort_exception_table(void);

/*
diff -urpN --exclude TAGS -X /home/rusty/devel/kernel/kernel-patches/current-dontdiff --minimal .17925-linux-2.5.38/include/asm-sparc64/uaccess.h .17925-linux-2.5.38.updated/include/asm-sparc64/uaccess.h
--- .17925-linux-2.5.38/include/asm-sparc64/uaccess.h 2002-05-24 15:20:33.000000000 +1000
+++ .17925-linux-2.5.38.updated/include/asm-sparc64/uaccess.h 2002-09-25 02:08:05.000000000 +1000
@@ -84,8 +84,9 @@ struct exception_table_entry
unsigned insn, fixup;
};

-/* Returns 0 if exception not found and fixup otherwise. */
-extern unsigned long search_exception_table(unsigned long, unsigned long *);
+/* Special exable search, which handles ranges. Returns fixup */
+extern unsigned long search_exception_tables_sparc(unsigned long addr,
+ unsigned long *g2);

extern void __ret_efault(void);

diff -urpN --exclude TAGS -X /home/rusty/devel/kernel/kernel-patches/current-dontdiff --minimal .17925-linux-2.5.38/include/linux/module.h .17925-linux-2.5.38.updated/include/linux/module.h
--- .17925-linux-2.5.38/include/linux/module.h 2002-09-25 02:07:40.000000000 +1000
+++ .17925-linux-2.5.38.updated/include/linux/module.h 2002-09-25 02:10:11.000000000 +1000
@@ -25,6 +25,12 @@
#define MODULE_DEVICE_TABLE(type,name)
#define MODULE_PARM_DESC(var,desc)

+/* Archs provide a method of finding the correct exception table. */
+const struct exception_table_entry *
+search_extable(const struct exception_table_entry *first,
+ const struct exception_table_entry *last,
+ unsigned long value);
+
#ifdef MODULE
/* This is magically filled in by the linker, but THIS_MODULE must be
a constant so it works in initializers. */
@@ -119,6 +125,9 @@ struct kernel_symbol_group
const struct kernel_symbol *syms;
};

+/* Given an address, look for it in the exception tables */
+const struct exception_table_entry *search_exception_tables(unsigned long add);
+
struct exception_table
{
struct list_head list;
@@ -287,6 +296,19 @@ static inline int module_put(struct modu
#define EXPORT_SYMBOL(sym) 0
#define EXPORT_SYMBOL_GPL(sym) 0

+extern const struct exception_table_entry __start___ex_table[];
+extern const struct exception_table_entry __stop___ex_table[];
+
+/* Given an address, look for it in the exception tables. */
+static inline const struct exception_table_entry *
+search_exception_tables(unsigned long add)
+{
+ /* There is only one, and it doesn't change */
+ return search_extable(__start___ex_table,
+ __stop___ex_table - 1,
+ add);
+}
+
/* Get/put a kernel symbol (calls should be symmetric) */
#define symbol_get(x) ((typeof(&x))(0))

@@ -296,10 +318,6 @@ static inline int module_put(struct modu
#define __unsafe(mod)
#endif /* CONFIG_MODULES */

-/* For archs to search exception tables */
-extern struct list_head extables;
-extern spinlock_t modlist_lock;
-
/* BELOW HERE ALL THESE ARE OBSOLETE AND WILL VANISH */
#define __MOD_INC_USE_COUNT(mod) \
do { try_module_get(mod); __unsafe(mod); } while(0)
diff -urpN --exclude TAGS -X /home/rusty/devel/kernel/kernel-patches/current-dontdiff --minimal .17925-linux-2.5.38/kernel/module.c .17925-linux-2.5.38.updated/kernel/module.c
--- .17925-linux-2.5.38/kernel/module.c 2002-09-25 02:07:40.000000000 +1000
+++ .17925-linux-2.5.38.updated/kernel/module.c 2002-09-25 02:11:50.000000000 +1000
@@ -44,10 +44,10 @@ extern const struct kernel_symbol __star
extern const struct kernel_symbol __stop_gpl_ksymtab[];

/* Protects extables and symbol tables */
-spinlock_t modlist_lock = SPIN_LOCK_UNLOCKED;
+static spinlock_t module_lock = SPIN_LOCK_UNLOCKED;

/* The exception and symbol tables: start with kernel only. */
-LIST_HEAD(extables);
+static LIST_HEAD(extables);
static LIST_HEAD(symbols);

static struct exception_table kernel_extable;
@@ -240,10 +240,10 @@ sys_delete_module(const char *name_user,
}

/* Remove symbols so module count can't increase from symbol_get() */
- spin_lock_irq(&modlist_lock);
+ spin_lock_irq(&module_lock);
list_del_init(&mod->symbols.list);
list_del_init(&mod->gpl_symbols.list);
- spin_unlock_irq(&modlist_lock);
+ spin_unlock_irq(&module_lock);

/* Mark it as non-live. */
mod->live = 0;
@@ -292,10 +292,10 @@ sys_delete_module(const char *name_user,
reanimate:
mod->live = 1;
try_module_get(mod); /* Can't fail */
- spin_lock_irq(&modlist_lock);
+ spin_lock_irq(&module_lock);
list_add(&mod->symbols.list, &kernel_symbols.list);
list_add(&mod->gpl_symbols.list, &kernel_symbols.list);
- spin_unlock_irq(&modlist_lock);
+ spin_unlock_irq(&module_lock);
ret = -EWOULDBLOCK;
goto out;
}
@@ -339,11 +339,11 @@ void __symbol_put(const char *symbol)
struct kernel_symbol_group *ksg;
unsigned long flags;

- spin_lock_irqsave(&modlist_lock, flags);
+ spin_lock_irqsave(&module_lock, flags);
if (!__find_symbol(symbol, &ksg, 1))
BUG();
module_put(ksg->owner);
- spin_unlock_irqrestore(&modlist_lock, flags);
+ spin_unlock_irqrestore(&module_lock, flags);
}
EXPORT_SYMBOL(__symbol_put);

@@ -568,14 +568,14 @@ unsigned long find_symbol_internal(Elf_S
return ret;
}
/* Look in other modules... */
- spin_lock_irq(&modlist_lock);
+ spin_lock_irq(&module_lock);
ret = __find_symbol(name, ksg, module_is_gpl(mod));
if (ret) {
/* This can fail due to OOM, or module unloading */
if (!use_module(mod, (*ksg)->owner))
ret = 0;
}
- spin_unlock_irq(&modlist_lock);
+ spin_unlock_irq(&module_lock);
return ret;
}

@@ -588,11 +588,11 @@ static void free_module(struct module *m

/* Delete from various lists */
list_del(&mod->list);
- spin_lock_irq(&modlist_lock);
+ spin_lock_irq(&module_lock);
list_del(&mod->symbols.list);
list_del(&mod->gpl_symbols.list);
list_del(&mod->extable.list);
- spin_unlock_irq(&modlist_lock);
+ spin_unlock_irq(&module_lock);

/* Module unload stuff */
module_unload_free(mod);
@@ -606,11 +606,11 @@ void *__symbol_get(const char *symbol)
struct kernel_symbol_group *ksg;
unsigned long value, flags;

- spin_lock_irqsave(&modlist_lock, flags);
+ spin_lock_irqsave(&module_lock, flags);
value = __find_symbol(symbol, &ksg, 1);
if (value && !try_module_get(ksg->owner))
value = 0;
- spin_unlock_irqrestore(&modlist_lock, flags);
+ spin_unlock_irqrestore(&module_lock, flags);

return (void *)value;
}
@@ -1147,9 +1147,9 @@ sys_init_module(void *umod,
(unsigned long)mod->module_core + mod->core_size);

/* Now sew it into exception list (just in case...). */
- spin_lock_irq(&modlist_lock);
+ spin_lock_irq(&module_lock);
list_add(&mod->extable.list, &extables);
- spin_unlock_irq(&modlist_lock);
+ spin_unlock_irq(&module_lock);

/* Start the module */
ret = mod->init();
@@ -1167,10 +1167,10 @@ sys_init_module(void *umod,
}

/* Now it's a first class citizen! */
- spin_lock_irq(&modlist_lock);
+ spin_lock_irq(&module_lock);
list_add(&mod->symbols.list, &kernel_symbols.list);
list_add(&mod->gpl_symbols.list, &kernel_symbols.list);
- spin_unlock_irq(&modlist_lock);
+ spin_unlock_irq(&module_lock);
list_add(&mod->list, &modules);

module_free(mod, mod->module_init);
@@ -1182,6 +1182,33 @@ sys_init_module(void *umod,
return 0;
}

+/* Given an address, look for it in the exception tables. If we used
+ a single linked list, we could get rid of the lock here if
+ !CONFIG_MODULE_UNLOAD, but who cares enough? */
+const struct exception_table_entry *search_exception_tables(unsigned long addr)
+{
+ struct list_head *i;
+ unsigned long flags;
+ const struct exception_table_entry *found = NULL;
+
+ spin_lock_irqsave(&module_lock, flags);
+ list_for_each(i, &extables) {
+ struct exception_table *t
+ = list_entry(i, struct exception_table, list);
+ if (t->num_entries > 0) {
+ found = search_extable(t->entry,
+ t->entry + t->num_entries-1,
+ addr);
+ if (found) break;
+ }
+ }
+ spin_unlock_irqrestore(&module_lock, flags);
+
+ /* Now, if we found one, we are running inside it now, hence
+ we cannot unload the module, hence no refcnt needed. */
+ return found;
+}
+
/* Called by the /proc file system to return a current list of
modules. Al Viro came up with this interface as an "improvement".
God save us from any more such interface improvements. */

--
Anyone who quotes me in their sig is an idiot. -- Rusty Russell.