[S390] user-copy optimization fallout.
Fix new restore_sigregs function. It copies the user space copy of the old psw without correcting the psw.mask and the psw.addr high order bit. While we are at it, simplify save_sigregs a bit. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
This commit is contained in:
Родитель
aa97b10252
Коммит
b05e370352
|
@ -113,17 +113,15 @@ sys_sigaltstack(const stack_t __user *uss, stack_t __user *uoss,
|
|||
/* Returns non-zero on fault. */
|
||||
static int save_sigregs(struct pt_regs *regs, _sigregs __user *sregs)
|
||||
{
|
||||
unsigned long old_mask = regs->psw.mask;
|
||||
_sigregs user_sregs;
|
||||
|
||||
save_access_regs(current->thread.acrs);
|
||||
|
||||
/* Copy a 'clean' PSW mask to the user to avoid leaking
|
||||
information about whether PER is currently on. */
|
||||
regs->psw.mask = PSW_MASK_MERGE(PSW_USER_BITS, regs->psw.mask);
|
||||
memcpy(&user_sregs.regs.psw, ®s->psw, sizeof(sregs->regs.psw) +
|
||||
sizeof(sregs->regs.gprs));
|
||||
regs->psw.mask = old_mask;
|
||||
user_sregs.regs.psw.mask = PSW_MASK_MERGE(PSW_USER_BITS, regs->psw.mask);
|
||||
user_sregs.regs.psw.addr = regs->psw.addr;
|
||||
memcpy(&user_sregs.regs.gprs, ®s->gprs, sizeof(sregs->regs.gprs));
|
||||
memcpy(&user_sregs.regs.acrs, current->thread.acrs,
|
||||
sizeof(sregs->regs.acrs));
|
||||
/*
|
||||
|
@ -139,7 +137,6 @@ static int save_sigregs(struct pt_regs *regs, _sigregs __user *sregs)
|
|||
/* Returns positive number on error */
|
||||
static int restore_sigregs(struct pt_regs *regs, _sigregs __user *sregs)
|
||||
{
|
||||
unsigned long old_mask = regs->psw.mask;
|
||||
int err;
|
||||
_sigregs user_sregs;
|
||||
|
||||
|
@ -147,12 +144,12 @@ static int restore_sigregs(struct pt_regs *regs, _sigregs __user *sregs)
|
|||
current_thread_info()->restart_block.fn = do_no_restart_syscall;
|
||||
|
||||
err = __copy_from_user(&user_sregs, sregs, sizeof(_sigregs));
|
||||
regs->psw.mask = PSW_MASK_MERGE(old_mask, regs->psw.mask);
|
||||
regs->psw.addr |= PSW_ADDR_AMODE;
|
||||
if (err)
|
||||
return err;
|
||||
memcpy(®s->psw, &user_sregs.regs.psw, sizeof(sregs->regs.psw) +
|
||||
sizeof(sregs->regs.gprs));
|
||||
regs->psw.mask = PSW_MASK_MERGE(regs->psw.mask,
|
||||
user_sregs.regs.psw.mask);
|
||||
regs->psw.addr = PSW_ADDR_AMODE | user_sregs.regs.psw.addr;
|
||||
memcpy(®s->gprs, &user_sregs.regs.gprs, sizeof(sregs->regs.gprs));
|
||||
memcpy(¤t->thread.acrs, &user_sregs.regs.acrs,
|
||||
sizeof(sregs->regs.acrs));
|
||||
restore_access_regs(current->thread.acrs);
|
||||
|
|
Загрузка…
Ссылка в новой задаче