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frv: switch to use of fixup_exception()
Massage frv search_exception_table() to a) taking pt_regs pointer as explicit argument b) updating ->pc on success Simplifies callers a bit and allows to convert to generic extable.h, while we are at it. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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commit
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5 changed files with 18 additions and 46 deletions
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@ -1,6 +1,7 @@
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generic-y += clkdev.h
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generic-y += exec.h
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generic-y += extable.h
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generic-y += irq_work.h
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generic-y += mcs_spinlock.h
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generic-y += mm-arch-hooks.h
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@ -18,6 +18,7 @@
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#include <linux/mm.h>
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#include <asm/segment.h>
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#include <asm/sections.h>
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#include <asm/extable.h>
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#define __ptr(x) ((unsigned long __force *)(x))
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@ -59,26 +60,6 @@ static inline int ___range_ok(unsigned long addr, unsigned long size)
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#define access_ok(type,addr,size) (__range_ok((void __user *)(addr), (size)) == 0)
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#define __access_ok(addr,size) (__range_ok((addr), (size)) == 0)
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/*
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* The exception table consists of pairs of addresses: the first is the
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* address of an instruction that is allowed to fault, and the second is
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* the address at which the program should continue. No registers are
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* modified, so it is entirely up to the continuation code to figure out
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* what to do.
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*
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* All the routines below use bits of fixup code that are out of line
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* with the main instruction path. This means when everything is well,
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* we don't even have to jump over them. Further, they do not intrude
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* on our cache or tlb entries.
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*/
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struct exception_table_entry
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{
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unsigned long insn, fixup;
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};
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/* Returns 0 if exception not found and fixup otherwise. */
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extern unsigned long search_exception_table(unsigned long);
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/*
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* These are the main single-value transfer routines. They automatically
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@ -314,6 +295,4 @@ extern long strnlen_user(const char __user *src, long count);
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#define strlen_user(str) strnlen_user(str, 32767)
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extern unsigned long search_exception_table(unsigned long addr);
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#endif /* _ASM_UACCESS_H */
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@ -360,13 +360,8 @@ asmlinkage void memory_access_exception(unsigned long esr0,
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siginfo_t info;
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#ifdef CONFIG_MMU
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unsigned long fixup;
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fixup = search_exception_table(__frame->pc);
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if (fixup) {
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__frame->pc = fixup;
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if (fixup_exception(__frame))
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return;
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}
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#endif
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die_if_kernel("-- Memory Access Exception --\n"
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@ -10,40 +10,39 @@ extern const void __memset_end, __memset_user_error_lr, __memset_user_error_hand
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extern const void __memcpy_end, __memcpy_user_error_lr, __memcpy_user_error_handler;
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extern spinlock_t modlist_lock;
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/*****************************************************************************/
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/*
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* see if there's a fixup handler available to deal with a kernel fault
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*/
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unsigned long search_exception_table(unsigned long pc)
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int fixup_exception(struct pt_regs *regs)
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{
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const struct exception_table_entry *extab;
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unsigned long pc = regs->pc;
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/* determine if the fault lay during a memcpy_user or a memset_user */
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if (__frame->lr == (unsigned long) &__memset_user_error_lr &&
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if (regs->lr == (unsigned long) &__memset_user_error_lr &&
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(unsigned long) &memset <= pc && pc < (unsigned long) &__memset_end
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) {
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/* the fault occurred in a protected memset
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* - we search for the return address (in LR) instead of the program counter
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* - it was probably during a clear_user()
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*/
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return (unsigned long) &__memset_user_error_handler;
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regs->pc = (unsigned long) &__memset_user_error_handler;
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return 1;
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}
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if (__frame->lr == (unsigned long) &__memcpy_user_error_lr &&
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if (regs->lr == (unsigned long) &__memcpy_user_error_lr &&
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(unsigned long) &memcpy <= pc && pc < (unsigned long) &__memcpy_end
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) {
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/* the fault occurred in a protected memset
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* - we search for the return address (in LR) instead of the program counter
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* - it was probably during a copy_to/from_user()
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*/
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return (unsigned long) &__memcpy_user_error_handler;
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regs->pc = (unsigned long) &__memcpy_user_error_handler;
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return 1;
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}
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extab = search_exception_tables(pc);
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if (extab)
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return extab->fixup;
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if (extab) {
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regs->pc = extab->fixup;
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return 1;
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}
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return 0;
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} /* end search_exception_table() */
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}
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@ -33,7 +33,7 @@ asmlinkage void do_page_fault(int datammu, unsigned long esr0, unsigned long ear
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{
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struct vm_area_struct *vma;
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struct mm_struct *mm;
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unsigned long _pme, lrai, lrad, fixup;
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unsigned long _pme, lrai, lrad;
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unsigned long flags = 0;
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siginfo_t info;
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pgd_t *pge;
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@ -201,10 +201,8 @@ asmlinkage void do_page_fault(int datammu, unsigned long esr0, unsigned long ear
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no_context:
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/* are we prepared to handle this kernel fault? */
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if ((fixup = search_exception_table(__frame->pc)) != 0) {
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__frame->pc = fixup;
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if (fixup_exception(__frame))
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return;
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}
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/*
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* Oops. The kernel tried to access some bad page. We'll have to
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