renegade-project/linux-next
2
0
Fork 0
mirror of https://github.com/edk2-porting/linux-next.git synced 2024-12-22 20:23:57 +08:00
Code

powerpc/signal64: Rewrite rt_sigreturn() to minimise uaccess switches

Browse Source 
Add uaccess blocks and use the 'unsafe' versions of functions doing user
access where possible to reduce the number of times uaccess has to be
opened/closed.

Co-developed-by: Christopher M. Riedl <cmr@codefail.de>
Signed-off-by: Daniel Axtens <dja@axtens.net>
Signed-off-by: Christopher M. Riedl <cmr@codefail.de>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210227011259.11992-10-cmr@codefail.de
This commit is contained in:
Daniel Axtens 2021-02-26 19:12:58 -06:00 committed by Michael Ellerman
parent 96d7a4e06f
commit 0f92433b8f
1 changed files with 6 additions and 4 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

10
arch/powerpc/kernel/signal_64.c
View File

@ -822,11 +822,11 @@ SYSCALL_DEFINE0(rt_sigreturn)
*/
current->thread.regs->msr &= ~MSR_TS_MASK;
if (!user_read_access_begin(&uc->uc_mcontext, sizeof(uc->uc_mcontext)))
return -EFAULT;
if (__unsafe_restore_sigcontext(current, NULL, 1, &uc->uc_mcontext)) {
user_read_access_end();
goto badframe;
}
unsafe_restore_sigcontext(current, NULL, 1, &uc->uc_mcontext,
badframe_block);
user_read_access_end();
}
@ -836,6 +836,8 @@ SYSCALL_DEFINE0(rt_sigreturn)
set_thread_flag(TIF_RESTOREALL);
return 0;
badframe_block:
user_read_access_end();
badframe:
signal_fault(current, regs, "rt_sigreturn", uc);