mirror of
https://github.com/torvalds/linux.git
synced 2024-12-19 17:41:29 +00:00
7bbcdb1ca4
early_fixup_exception() is limited by the fact that it doesn't have a real struct pt_regs. Change both the 32-bit and 64-bit asm and the C code to pass and accept a real pt_regs. Tested-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: Andy Lutomirski <luto@kernel.org> Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Arjan van de Ven <arjan@linux.intel.com> Cc: Borislav Petkov <bp@alien8.de> Cc: KVM list <kvm@vger.kernel.org> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: xen-devel <Xen-devel@lists.xen.org> Link: http://lkml.kernel.org/r/e3fb680fcfd5e23e38237e8328b64a25cc121d37.1459605520.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
106 lines
2.4 KiB
C
106 lines
2.4 KiB
C
#include <linux/module.h>
|
|
#include <asm/uaccess.h>
|
|
|
|
typedef bool (*ex_handler_t)(const struct exception_table_entry *,
|
|
struct pt_regs *, int);
|
|
|
|
static inline unsigned long
|
|
ex_fixup_addr(const struct exception_table_entry *x)
|
|
{
|
|
return (unsigned long)&x->fixup + x->fixup;
|
|
}
|
|
static inline ex_handler_t
|
|
ex_fixup_handler(const struct exception_table_entry *x)
|
|
{
|
|
return (ex_handler_t)((unsigned long)&x->handler + x->handler);
|
|
}
|
|
|
|
bool ex_handler_default(const struct exception_table_entry *fixup,
|
|
struct pt_regs *regs, int trapnr)
|
|
{
|
|
regs->ip = ex_fixup_addr(fixup);
|
|
return true;
|
|
}
|
|
EXPORT_SYMBOL(ex_handler_default);
|
|
|
|
bool ex_handler_fault(const struct exception_table_entry *fixup,
|
|
struct pt_regs *regs, int trapnr)
|
|
{
|
|
regs->ip = ex_fixup_addr(fixup);
|
|
regs->ax = trapnr;
|
|
return true;
|
|
}
|
|
EXPORT_SYMBOL_GPL(ex_handler_fault);
|
|
|
|
bool ex_handler_ext(const struct exception_table_entry *fixup,
|
|
struct pt_regs *regs, int trapnr)
|
|
{
|
|
/* Special hack for uaccess_err */
|
|
current_thread_info()->uaccess_err = 1;
|
|
regs->ip = ex_fixup_addr(fixup);
|
|
return true;
|
|
}
|
|
EXPORT_SYMBOL(ex_handler_ext);
|
|
|
|
bool ex_has_fault_handler(unsigned long ip)
|
|
{
|
|
const struct exception_table_entry *e;
|
|
ex_handler_t handler;
|
|
|
|
e = search_exception_tables(ip);
|
|
if (!e)
|
|
return false;
|
|
handler = ex_fixup_handler(e);
|
|
|
|
return handler == ex_handler_fault;
|
|
}
|
|
|
|
int fixup_exception(struct pt_regs *regs, int trapnr)
|
|
{
|
|
const struct exception_table_entry *e;
|
|
ex_handler_t handler;
|
|
|
|
#ifdef CONFIG_PNPBIOS
|
|
if (unlikely(SEGMENT_IS_PNP_CODE(regs->cs))) {
|
|
extern u32 pnp_bios_fault_eip, pnp_bios_fault_esp;
|
|
extern u32 pnp_bios_is_utter_crap;
|
|
pnp_bios_is_utter_crap = 1;
|
|
printk(KERN_CRIT "PNPBIOS fault.. attempting recovery.\n");
|
|
__asm__ volatile(
|
|
"movl %0, %%esp\n\t"
|
|
"jmp *%1\n\t"
|
|
: : "g" (pnp_bios_fault_esp), "g" (pnp_bios_fault_eip));
|
|
panic("do_trap: can't hit this");
|
|
}
|
|
#endif
|
|
|
|
e = search_exception_tables(regs->ip);
|
|
if (!e)
|
|
return 0;
|
|
|
|
handler = ex_fixup_handler(e);
|
|
return handler(e, regs, trapnr);
|
|
}
|
|
|
|
/* Restricted version used during very early boot */
|
|
int __init early_fixup_exception(struct pt_regs *regs, int trapnr)
|
|
{
|
|
const struct exception_table_entry *e;
|
|
unsigned long new_ip;
|
|
ex_handler_t handler;
|
|
|
|
e = search_exception_tables(regs->ip);
|
|
if (!e)
|
|
return 0;
|
|
|
|
new_ip = ex_fixup_addr(e);
|
|
handler = ex_fixup_handler(e);
|
|
|
|
/* special handling not supported during early boot */
|
|
if (handler != ex_handler_default)
|
|
return 0;
|
|
|
|
regs->ip = new_ip;
|
|
return 1;
|
|
}
|