diff mbox series

[v7,09/10] powerpc/signal64: Rewrite rt_sigreturn() to minimise uaccess switches

Message ID 20210227011259.11992-10-cmr@codefail.de (mailing list archive)
State Accepted
Headers show
Series Improve signal performance on PPC64 with KUAP | expand

Checks

Context Check Description
snowpatch_ozlabs/apply_patch warning Failed to apply on branch powerpc/merge (626a6c3d2e20da80aaa710104f34ea6037b28b33)
snowpatch_ozlabs/apply_patch warning Failed to apply on branch powerpc/next (6895c5ba7bdcc55eacad03cf309ab23be63b9cac)
snowpatch_ozlabs/apply_patch warning Failed to apply on branch linus/master (92bf22614b21a2706f4993b278017e437f7785b3)
snowpatch_ozlabs/apply_patch warning Failed to apply on branch powerpc/fixes (24321ac668e452a4942598533d267805f291fdc9)
snowpatch_ozlabs/apply_patch warning Failed to apply on branch linux-next (1e0d27fce010b0a4a9e595506b6ede75934c31be)
snowpatch_ozlabs/apply_patch fail Failed to apply to any branch

Commit Message

Christopher M. Riedl Feb. 27, 2021, 1:12 a.m. UTC 
From: Daniel Axtens <dja@axtens.net>

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.

Signed-off-by: Daniel Axtens <dja@axtens.net>
Co-developed-by: Christopher M. Riedl <cmr@codefail.de>
Signed-off-by: Christopher M. Riedl <cmr@codefail.de>
---
 arch/powerpc/kernel/signal_64.c | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)
diff mbox series

Patch

diff --git a/arch/powerpc/kernel/signal_64.c b/arch/powerpc/kernel/signal_64.c
index 788854734b9a..00c907022707 100644
--- a/arch/powerpc/kernel/signal_64.c
+++ b/arch/powerpc/kernel/signal_64.c
@@ -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);