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author | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-17 00:20:36 +0200 |
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committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-17 00:20:36 +0200 |
commit | 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch) | |
tree | 0bba044c4ce775e45a88a51686b5d9f90697ea9d /arch/frv/mm/extable.c | |
download | linux-1da177e4c3f41524e886b7f1b8a0c1fc7321cac2.tar.xz linux-1da177e4c3f41524e886b7f1b8a0c1fc7321cac2.zip |
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Diffstat (limited to 'arch/frv/mm/extable.c')
-rw-r--r-- | arch/frv/mm/extable.c | 91 |
1 files changed, 91 insertions, 0 deletions
diff --git a/arch/frv/mm/extable.c b/arch/frv/mm/extable.c new file mode 100644 index 000000000000..41be1128dc64 --- /dev/null +++ b/arch/frv/mm/extable.c @@ -0,0 +1,91 @@ +/* + * linux/arch/frv/mm/extable.c + */ + +#include <linux/config.h> +#include <linux/module.h> +#include <linux/spinlock.h> +#include <asm/uaccess.h> + +extern const struct exception_table_entry __attribute__((aligned(8))) __start___ex_table[]; +extern const struct exception_table_entry __attribute__((aligned(8))) __stop___ex_table[]; +extern const void __memset_end, __memset_user_error_lr, __memset_user_error_handler; +extern const void __memcpy_end, __memcpy_user_error_lr, __memcpy_user_error_handler; +extern spinlock_t modlist_lock; + +/*****************************************************************************/ +/* + * + */ +static inline unsigned long search_one_table(const struct exception_table_entry *first, + const struct exception_table_entry *last, + unsigned long value) +{ + while (first <= last) { + const struct exception_table_entry __attribute__((aligned(8))) *mid; + long diff; + + mid = (last - first) / 2 + first; + diff = mid->insn - value; + if (diff == 0) + return mid->fixup; + else if (diff < 0) + first = mid + 1; + else + last = mid - 1; + } + return 0; +} /* end search_one_table() */ + +/*****************************************************************************/ +/* + * see if there's a fixup handler available to deal with a kernel fault + */ +unsigned long search_exception_table(unsigned long pc) +{ + unsigned long ret = 0; + + /* determine if the fault lay during a memcpy_user or a memset_user */ + if (__frame->lr == (unsigned long) &__memset_user_error_lr && + (unsigned long) &memset <= pc && pc < (unsigned long) &__memset_end + ) { + /* the fault occurred in a protected memset + * - we search for the return address (in LR) instead of the program counter + * - it was probably during a clear_user() + */ + return (unsigned long) &__memset_user_error_handler; + } + else if (__frame->lr == (unsigned long) &__memcpy_user_error_lr && + (unsigned long) &memcpy <= pc && pc < (unsigned long) &__memcpy_end + ) { + /* the fault occurred in a protected memset + * - we search for the return address (in LR) instead of the program counter + * - it was probably during a copy_to/from_user() + */ + return (unsigned long) &__memcpy_user_error_handler; + } + +#ifndef CONFIG_MODULES + /* there is only the kernel to search. */ + ret = search_one_table(__start___ex_table, __stop___ex_table - 1, pc); + return ret; + +#else + /* the kernel is the last "module" -- no need to treat it special */ + unsigned long flags; + struct module *mp; + + 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, pc); + if (ret) + break; + } + + spin_unlock_irqrestore(&modlist_lock, flags); + return ret; +#endif +} /* end search_exception_table() */ |