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From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: linux-kernel@vger.kernel.org
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	stable@vger.kernel.org,
	Christophe Leroy <christophe.leroy@csgroup.eu>,
	Michael Ellerman <mpe@ellerman.id.au>
Subject: [PATCH 4.14 12/17] powerpc/8xx: Always fault when _PAGE_ACCESSED is not set
Date: Fri, 20 Nov 2020 12:03:23 +0100	[thread overview]
Message-ID: <20201120104541.014478524@linuxfoundation.org> (raw)
In-Reply-To: <20201120104540.414709708@linuxfoundation.org>

From: Christophe Leroy <christophe.leroy@csgroup.eu>

commit 29daf869cbab69088fe1755d9dd224e99ba78b56 upstream.

The kernel expects pte_young() to work regardless of CONFIG_SWAP.

Make sure a minor fault is taken to set _PAGE_ACCESSED when it
is not already set, regardless of the selection of CONFIG_SWAP.

This adds at least 3 instructions to the TLB miss exception
handlers fast path. Following patch will reduce this overhead.

Also update the rotation instruction to the correct number of bits
to reflect all changes done to _PAGE_ACCESSED over time.

Fixes: d069cb4373fe ("powerpc/8xx: Don't touch ACCESSED when no SWAP.")
Fixes: 5f356497c384 ("powerpc/8xx: remove unused _PAGE_WRITETHRU")
Fixes: e0a8e0d90a9f ("powerpc/8xx: Handle PAGE_USER via APG bits")
Fixes: 5b2753fc3e8a ("powerpc/8xx: Implementation of PAGE_EXEC")
Fixes: a891c43b97d3 ("powerpc/8xx: Prepare handlers for _PAGE_HUGE for 512k pages.")
Cc: stable@vger.kernel.org
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/af834e8a0f1fa97bfae65664950f0984a70c4750.1602492856.git.christophe.leroy@csgroup.eu
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 arch/powerpc/kernel/head_8xx.S |    8 ++------
 1 file changed, 2 insertions(+), 6 deletions(-)

--- a/arch/powerpc/kernel/head_8xx.S
+++ b/arch/powerpc/kernel/head_8xx.S
@@ -398,11 +398,9 @@ _ENTRY(ITLBMiss_cmp)
 #if defined (CONFIG_HUGETLB_PAGE) && defined (CONFIG_PPC_4K_PAGES)
 	rlwimi	r10, r11, 1, MI_SPS16K
 #endif
-#ifdef CONFIG_SWAP
-	rlwinm	r11, r10, 32-5, _PAGE_PRESENT
+	rlwinm	r11, r10, 32-11, _PAGE_PRESENT
 	and	r11, r11, r10
 	rlwimi	r10, r11, 0, _PAGE_PRESENT
-#endif
 	li	r11, RPN_PATTERN
 	/* The Linux PTE won't go exactly into the MMU TLB.
 	 * Software indicator bits 20-23 and 28 must be clear.
@@ -528,11 +526,9 @@ _ENTRY(DTLBMiss_jmp)
 	 * r11 = ((r10 & PRESENT) & ((r10 & ACCESSED) >> 5));
 	 * r10 = (r10 & ~PRESENT) | r11;
 	 */
-#ifdef CONFIG_SWAP
-	rlwinm	r11, r10, 32-5, _PAGE_PRESENT
+	rlwinm	r11, r10, 32-11, _PAGE_PRESENT
 	and	r11, r11, r10
 	rlwimi	r10, r11, 0, _PAGE_PRESENT
-#endif
 	/* The Linux PTE won't go exactly into the MMU TLB.
 	 * Software indicator bits 22 and 28 must be clear.
 	 * Software indicator bits 24, 25, 26, and 27 must be



  parent reply	other threads:[~2020-11-20 11:05 UTC|newest]

Thread overview: 20+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-11-20 11:03 [PATCH 4.14 00/17] 4.14.208-rc1 review Greg Kroah-Hartman
2020-11-20 11:03 ` [PATCH 4.14 01/17] powerpc/64s: Define MASKABLE_RELON_EXCEPTION_PSERIES_OOL Greg Kroah-Hartman
2020-11-20 11:03 ` [PATCH 4.14 02/17] powerpc/64s: move some exception handlers out of line Greg Kroah-Hartman
2020-11-20 11:03 ` [PATCH 4.14 03/17] powerpc/64s: flush L1D on kernel entry Greg Kroah-Hartman
2020-11-20 11:03 ` [PATCH 4.14 04/17] powerpc: Add a framework for user access tracking Greg Kroah-Hartman
2020-11-20 11:03 ` [PATCH 4.14 05/17] powerpc: Implement user_access_begin and friends Greg Kroah-Hartman
2020-11-20 11:03 ` [PATCH 4.14 06/17] powerpc: Fix __clear_user() with KUAP enabled Greg Kroah-Hartman
2020-11-20 11:03 ` [PATCH 4.14 07/17] powerpc/uaccess: Evaluate macro arguments once, before user access is allowed Greg Kroah-Hartman
2020-11-20 11:03 ` [PATCH 4.14 08/17] powerpc/64s: flush L1D after user accesses Greg Kroah-Hartman
2020-11-20 11:03 ` [PATCH 4.14 09/17] i2c: imx: use clk notifier for rate changes Greg Kroah-Hartman
2020-11-20 11:03 ` [PATCH 4.14 10/17] i2c: imx: Fix external abort on interrupt in exit paths Greg Kroah-Hartman
2020-11-20 11:03 ` [PATCH 4.14 11/17] gpio: mockup: fix resource leak in error path Greg Kroah-Hartman
2020-11-20 11:03 ` Greg Kroah-Hartman [this message]
2020-11-20 11:03 ` [PATCH 4.14 13/17] Input: sunkbd - avoid use-after-free in teardown paths Greg Kroah-Hartman
2020-11-20 11:03 ` [PATCH 4.14 14/17] mac80211: always wind down STA state Greg Kroah-Hartman
2020-11-20 11:03 ` [PATCH 4.14 15/17] can: proc: can_remove_proc(): silence remove_proc_entry warning Greg Kroah-Hartman
2020-11-20 11:03 ` [PATCH 4.14 16/17] KVM: x86: clflushopt should be treated as a no-op by emulation Greg Kroah-Hartman
2020-11-20 11:03 ` [PATCH 4.14 17/17] ACPI: GED: fix -Wformat Greg Kroah-Hartman
2020-11-21 11:46 ` [PATCH 4.14 00/17] 4.14.208-rc1 review Naresh Kamboju
2020-11-21 18:36 ` Guenter Roeck

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