x86/mce: Provide method to find out the type of an exception handler

Avoid a proliferation of ex_has_*_handler() functions by having just
one function that returns the type of the handler (if any).

Drop the __visible attribute for this function. It is not called
from assembler so the attribute is not necessary.

Signed-off-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20201006210910.21062-3-tony.luck@intel.com
This commit is contained in:
Tony Luck 2020-10-06 14:09:06 -07:00 committed by Borislav Petkov
parent 41ce0564bf
commit a05d54c41e
3 changed files with 20 additions and 6 deletions

View file

@ -29,10 +29,17 @@ struct pt_regs;
(b)->handler = (tmp).handler - (delta); \
} while (0)
enum handler_type {
EX_HANDLER_NONE,
EX_HANDLER_FAULT,
EX_HANDLER_UACCESS,
EX_HANDLER_OTHER
};
extern int fixup_exception(struct pt_regs *regs, int trapnr,
unsigned long error_code, unsigned long fault_addr);
extern int fixup_bug(struct pt_regs *regs, int trapnr);
extern bool ex_has_fault_handler(unsigned long ip);
extern enum handler_type ex_get_fault_handler_type(unsigned long ip);
extern void early_fixup_exception(struct pt_regs *regs, int trapnr);
#endif

View file

@ -225,10 +225,13 @@ static struct severity {
*/
static int error_context(struct mce *m, struct pt_regs *regs)
{
enum handler_type t;
if ((m->cs & 3) == 3)
return IN_USER;
if (mc_recoverable(m->mcgstatus) && ex_has_fault_handler(m->ip)) {
t = ex_get_fault_handler_type(m->ip);
if (mc_recoverable(m->mcgstatus) && t == EX_HANDLER_FAULT) {
m->kflags |= MCE_IN_KERNEL_RECOV;
return IN_KERNEL_RECOV;
}

View file

@ -125,17 +125,21 @@ __visible bool ex_handler_clear_fs(const struct exception_table_entry *fixup,
}
EXPORT_SYMBOL(ex_handler_clear_fs);
__visible bool ex_has_fault_handler(unsigned long ip)
enum handler_type ex_get_fault_handler_type(unsigned long ip)
{
const struct exception_table_entry *e;
ex_handler_t handler;
e = search_exception_tables(ip);
if (!e)
return false;
return EX_HANDLER_NONE;
handler = ex_fixup_handler(e);
return handler == ex_handler_fault;
if (handler == ex_handler_fault)
return EX_HANDLER_FAULT;
else if (handler == ex_handler_uaccess)
return EX_HANDLER_UACCESS;
else
return EX_HANDLER_OTHER;
}
int fixup_exception(struct pt_regs *regs, int trapnr, unsigned long error_code,