linux-kernel - [tip: x86/urgent] x86/mm: Fix pti_clone_entry

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Message-ID: <172251743219.2215.3718826163204561626.tip-bot2@tip-bot2>
Date: Thu, 01 Aug 2024 13:03:52 -0000
From: "tip-bot2 for Peter Zijlstra" <tip-bot2@...utronix.de>
To: linux-tip-commits@...r.kernel.org
Cc: "Peter Zijlstra (Intel)" <peterz@...radead.org>, x86@...nel.org,
 linux-kernel@...r.kernel.org
Subject: [tip: x86/urgent] x86/mm: Fix pti_clone_entry_text() for i386

The following commit has been merged into the x86/urgent branch of tip:

Commit-ID:     3db03fb4995ef85fc41e86262ead7b4852f4bcf0
Gitweb:        https://git.kernel.org/tip/3db03fb4995ef85fc41e86262ead7b4852f4bcf0
Author:        Peter Zijlstra <peterz@...radead.org>
AuthorDate:    Thu, 01 Aug 2024 12:42:25 +02:00
Committer:     Peter Zijlstra <peterz@...radead.org>
CommitterDate: Thu, 01 Aug 2024 14:52:56 +02:00

x86/mm: Fix pti_clone_entry_text() for i386

While x86_64 has PMD aligned text sections, i386 does not have this
luxery. Notably ALIGN_ENTRY_TEXT_END is empty and _etext has PAGE
alignment.

This means that text on i386 can be page granular at the tail end,
which in turn means that the PTI text clones should consistently
account for this.

Make pti_clone_entry_text() consistent with pti_clone_kernel_text().

Fixes: 16a3fe634f6a ("x86/mm/pti: Clone kernel-image on PTE level for 32 bit")
Signed-off-by: Peter Zijlstra (Intel) <peterz@...radead.org>
---
 arch/x86/mm/pti.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/x86/mm/pti.c b/arch/x86/mm/pti.c
index 48c5032..bfdf5f4 100644
--- a/arch/x86/mm/pti.c
+++ b/arch/x86/mm/pti.c
@@ -496,7 +496,7 @@ static void pti_clone_entry_text(void)
 {
 	pti_clone_pgtable((unsigned long) __entry_text_start,
 			  (unsigned long) __entry_text_end,
-			  PTI_CLONE_PMD);
+			  PTI_LEVEL_KERNEL_IMAGE);
 }
 
 /*