linux-kernel - [PATCH] x86/ioperm: Save an indentation level in tss_update_io

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite for Android: free password hash cracker in your pocket

[<prev] [next>] [day] [month] [year] [list]

Message-Id: <20191130150053.23014-1-bp@alien8.de>
Date:   Sat, 30 Nov 2019 16:00:53 +0100
From:   Borislav Petkov <bp@...en8.de>
To:     X86 ML <x86@...nel.org>
Cc:     Thomas Gleixner <tglx@...utronix.de>
Subject: [PATCH] x86/ioperm: Save an indentation level in tss_update_io_bitmap()

From: Borislav Petkov <bp@...e.de>

... for better readability.

No functional changes.

Signed-off-by: Borislav Petkov <bp@...e.de>
Cc: Thomas Gleixner <tglx@...utronix.de>
Cc: x86@...nel.org
---
 arch/x86/kernel/process.c | 52 +++++++++++++++++++--------------------
 1 file changed, 26 insertions(+), 26 deletions(-)

diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c
index bd2a11ca5dd6..17ef878fd5dd 100644
--- a/arch/x86/kernel/process.c
+++ b/arch/x86/kernel/process.c
@@ -377,37 +377,37 @@ static void tss_copy_io_bitmap(struct tss_struct *tss, struct io_bitmap *iobm)
 void tss_update_io_bitmap(void)
 {
 	struct tss_struct *tss = this_cpu_ptr(&cpu_tss_rw);
+	struct thread_struct *t = &current->thread;
 	u16 *base = &tss->x86_tss.io_bitmap_base;
 
-	if (test_thread_flag(TIF_IO_BITMAP)) {
-		struct thread_struct *t = &current->thread;
-
-		if (IS_ENABLED(CONFIG_X86_IOPL_IOPERM) && t->iopl_emul == 3) {
-			*base = IO_BITMAP_OFFSET_VALID_ALL;
-		} else {
-			struct io_bitmap *iobm = t->io_bitmap;
-			/*
-			 * Only copy bitmap data when the sequence number
-			 * differs. The update time is accounted to the
-			 * incoming task.
-			 */
-			if (tss->io_bitmap.prev_sequence != iobm->sequence)
-				tss_copy_io_bitmap(tss, iobm);
-
-			/* Enable the bitmap */
-			*base = IO_BITMAP_OFFSET_VALID_MAP;
-		}
+	if (!test_thread_flag(TIF_IO_BITMAP)) {
+		tss_invalidate_io_bitmap(tss);
+		return;
+	}
+
+	if (IS_ENABLED(CONFIG_X86_IOPL_IOPERM) && t->iopl_emul == 3) {
+		*base = IO_BITMAP_OFFSET_VALID_ALL;
+	} else {
+		struct io_bitmap *iobm = t->io_bitmap;
+
 		/*
-		 * Make sure that the TSS limit is covering the io bitmap.
-		 * It might have been cut down by a VMEXIT to 0x67 which
-		 * would cause a subsequent I/O access from user space to
-		 * trigger a #GP because tbe bitmap is outside the TSS
-		 * limit.
+		 * Only copy bitmap data when the sequence number differs. The
+		 * update time is accounted to the incoming task.
 		 */
-		refresh_tss_limit();
-	} else {
-		tss_invalidate_io_bitmap(tss);
+		if (tss->io_bitmap.prev_sequence != iobm->sequence)
+			tss_copy_io_bitmap(tss, iobm);
+
+		/* Enable the bitmap */
+		*base = IO_BITMAP_OFFSET_VALID_MAP;
 	}
+
+	/*
+	 * Make sure that the TSS limit is covering the io bitmap. It might have
+	 * been cut down by a VMEXIT to 0x67 which would cause a subsequent I/O
+	 * access from user space to trigger a #GP because tbe bitmap is outside
+	 * the TSS limit.
+	 */
+	refresh_tss_limit();
 }
 #else /* CONFIG_X86_IOPL_IOPERM */
 static inline void switch_to_bitmap(unsigned long tifp) { }
-- 
2.21.0