diff mbox series

[v4,3/6] asm-generic/tlb, arch: Invert CONFIG_HAVE_RCU_TABLE_INVALIDATE

Message ID 20200520083025.229011-4-santosh@fossix.org (mailing list archive)
State Superseded
Headers show
Series Memory corruption may occur due to incorrent tlb flush | expand

Checks

Context Check Description
snowpatch_ozlabs/apply_patch warning Failed to apply on branch powerpc/merge (7b06fb8795ffea9d12be45a172197c3307955479)
snowpatch_ozlabs/apply_patch warning Failed to apply on branch powerpc/next (30df74d67d48949da87e3a5b57c381763e8fd526)
snowpatch_ozlabs/apply_patch warning Failed to apply on branch linus/master (115a54162a6c0d0ef2aef25ebd0b61fc5e179ebe)
snowpatch_ozlabs/apply_patch warning Failed to apply on branch powerpc/fixes (249c9b0cd193d983c3a0b00f3fd3b92333bfeebe)
snowpatch_ozlabs/apply_patch warning Failed to apply on branch linux-next (fb57b1fabcb28f358901b2df90abd2b48abc1ca8)
snowpatch_ozlabs/apply_patch fail Failed to apply to any branch

Commit Message

Santosh Sivaraj May 20, 2020, 8:30 a.m. UTC 
From: Peter Zijlstra <peterz@infradead.org>

commit 96bc9567cbe112e9320250f01b9c060c882e8619 upstream

Make issuing a TLB invalidate for page-table pages the normal case.

The reason is twofold:

 - too many invalidates is safer than too few,
 - most architectures use the linux page-tables natively
   and would thus require this.

Make it an opt-out, instead of an opt-in.

No change in behavior intended.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: <stable@vger.kernel.org> # 4.19
Signed-off-by: Santosh Sivaraj <santosh@fossix.org>
[santosh: prerequisite for upcoming tlbflush backports]
---
 arch/Kconfig         | 2 +-
 arch/powerpc/Kconfig | 1 +
 arch/sparc/Kconfig   | 1 +
 arch/x86/Kconfig     | 1 -
 mm/memory.c          | 2 +-
 5 files changed, 4 insertions(+), 3 deletions(-)

Comments

gregkh@linuxfoundation.org May 26, 2020, 11 a.m. UTC | #1 
On Wed, May 20, 2020 at 02:00:22PM +0530, Santosh Sivaraj wrote:
> From: Peter Zijlstra <peterz@infradead.org>
> 
> commit 96bc9567cbe112e9320250f01b9c060c882e8619 upstream
> 
> Make issuing a TLB invalidate for page-table pages the normal case.
> 
> The reason is twofold:
> 
>  - too many invalidates is safer than too few,
>  - most architectures use the linux page-tables natively
>    and would thus require this.
> 
> Make it an opt-out, instead of an opt-in.
> 
> No change in behavior intended.
> 
> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
> Cc: <stable@vger.kernel.org> # 4.19
> Signed-off-by: Santosh Sivaraj <santosh@fossix.org>
> [santosh: prerequisite for upcoming tlbflush backports]
> ---
>  arch/Kconfig         | 2 +-
>  arch/powerpc/Kconfig | 1 +
>  arch/sparc/Kconfig   | 1 +
>  arch/x86/Kconfig     | 1 -
>  mm/memory.c          | 2 +-
>  5 files changed, 4 insertions(+), 3 deletions(-)

Why did you not also change arch/arm64/Kconfig and
include/asm-generic/tlb.h like the original patch changed?

Why can those files be ignored/left out?  You need to explain that in
the backport section, all you said was "prerequisite..." and did not say
why you changed this patch.

Please fix up, and make sure you do the same for all of the other
patches in this series for when you resend it.

thanks,

greg k-h
diff mbox series

Patch

diff --git a/arch/Kconfig b/arch/Kconfig
index a336548487e6..061a12b8140e 100644
--- a/arch/Kconfig
+++ b/arch/Kconfig
@@ -363,7 +363,7 @@  config HAVE_ARCH_JUMP_LABEL
 config HAVE_RCU_TABLE_FREE
 	bool
 
-config HAVE_RCU_TABLE_INVALIDATE
+config HAVE_RCU_TABLE_NO_INVALIDATE
 	bool
 
 config ARCH_HAVE_NMI_SAFE_CMPXCHG
diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index 6f475dc5829b..e09cfb109b8c 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -216,6 +216,7 @@  config PPC
 	select HAVE_PERF_REGS
 	select HAVE_PERF_USER_STACK_DUMP
 	select HAVE_RCU_TABLE_FREE		if SMP
+	select HAVE_RCU_TABLE_NO_INVALIDATE	if HAVE_RCU_TABLE_FREE
 	select HAVE_REGS_AND_STACK_ACCESS_API
 	select HAVE_RELIABLE_STACKTRACE		if PPC64 && CPU_LITTLE_ENDIAN
 	select HAVE_SYSCALL_TRACEPOINTS
diff --git a/arch/sparc/Kconfig b/arch/sparc/Kconfig
index e6f2a38d2e61..d90d632868aa 100644
--- a/arch/sparc/Kconfig
+++ b/arch/sparc/Kconfig
@@ -64,6 +64,7 @@  config SPARC64
 	select HAVE_KRETPROBES
 	select HAVE_KPROBES
 	select HAVE_RCU_TABLE_FREE if SMP
+	select HAVE_RCU_TABLE_NO_INVALIDATE if HAVE_RCU_TABLE_FREE
 	select HAVE_MEMBLOCK_NODE_MAP
 	select HAVE_ARCH_TRANSPARENT_HUGEPAGE
 	select HAVE_DYNAMIC_FTRACE
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index af35f5caadbe..181d0d522977 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -181,7 +181,6 @@  config X86
 	select HAVE_PERF_REGS
 	select HAVE_PERF_USER_STACK_DUMP
 	select HAVE_RCU_TABLE_FREE		if PARAVIRT
-	select HAVE_RCU_TABLE_INVALIDATE	if HAVE_RCU_TABLE_FREE
 	select HAVE_REGS_AND_STACK_ACCESS_API
 	select HAVE_RELIABLE_STACKTRACE		if X86_64 && (UNWINDER_FRAME_POINTER || UNWINDER_ORC) && STACK_VALIDATION
 	select HAVE_STACKPROTECTOR		if CC_HAS_SANE_STACKPROTECTOR
diff --git a/mm/memory.c b/mm/memory.c
index 1832c5ed6ac0..ba5689610c04 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -327,7 +327,7 @@  bool __tlb_remove_page_size(struct mmu_gather *tlb, struct page *page, int page_
  */
 static inline void tlb_table_invalidate(struct mmu_gather *tlb)
 {
-#ifdef CONFIG_HAVE_RCU_TABLE_INVALIDATE
+#ifndef CONFIG_HAVE_RCU_TABLE_NO_INVALIDATE
 	/*
 	 * Invalidate page-table caches used by hardware walkers. Then we still
 	 * need to RCU-sched wait while freeing the pages because software