[PATCH] powerpc/mm: Fix kernel crash on page table free

Subsystems: linux for powerpc (32-bit and 64-bit), the rest

STALE2971d

4 messages, 3 authors, 2018-06-15 · open the first message on its own page

[PATCH] powerpc/mm: Fix kernel crash on page table free

From: Aneesh Kumar K.V <hidden>
Date: 2018-05-30 12:32:41

Fix the below crash on BookE 64. pgtable_page_dtor expects struct page *arg.

Also call the destructor on non book3s platforms correctly. This free up the
split ptl locks correctly if we had allocated them before.

Call Trace:
[c0000000f30c7520] [c00000000021eeec] .kmem_cache_free+0x9c/0x44c (unreliable)
[c0000000f30c75c0] [c0000000001ee07c] .ptlock_free+0x1c/0x30
[c0000000f30c7630] [c0000000001ee260] .tlb_remove_table+0xdc/0x224
[c0000000f30c76c0] [c0000000001ee640] .free_pgd_range+0x298/0x500
[c0000000f30c77d0] [c000000000232afc] .shift_arg_pages+0x10c/0x1e0
[c0000000f30c7910] [c000000000232dd0] .setup_arg_pages+0x200/0x25c
[c0000000f30c79c0] [c0000000002ad4fc] .load_elf_binary+0x450/0x16c8
[c0000000f30c7b10] [c000000000234914] .search_binary_handler.part.11+0x9c/0x248
[c0000000f30c7bb0] [c00000000023595c] .do_execveat_common.isra.13+0x868/0xc18
[c0000000f30c7cb0] [c00000000000184c] .run_init_process+0x34/0x4c
[c0000000f30c7d30] [c000000000001880] .try_to_run_init_process+0x1c/0x68
[c0000000f30c7db0] [c000000000002bd8] .kernel_init+0xdc/0x130
[c0000000f30c7e30] [c0000000000009dc] .ret_from_kernel_thread+0x58/0x7c

Fixes: 702346768 ("powerpc/mm/nohash: Remove pte fragment dependency from nohash")
Signed-off-by: Aneesh Kumar K.V <redacted>
---
 arch/powerpc/include/asm/book3s/32/pgalloc.h | 1 +
 arch/powerpc/include/asm/nohash/32/pgalloc.h | 1 +
 arch/powerpc/include/asm/nohash/64/pgalloc.h | 2 +-
 3 files changed, 3 insertions(+), 1 deletion(-)

diff --git a/arch/powerpc/include/asm/book3s/32/pgalloc.h b/arch/powerpc/include/asm/book3s/32/pgalloc.h
index 5073cc75f1c8..6a6673907e45 100644
--- a/arch/powerpc/include/asm/book3s/32/pgalloc.h
+++ b/arch/powerpc/include/asm/book3s/32/pgalloc.h

@@ -99,6 +99,7 @@ static inline void pte_free(struct mm_struct *mm, pgtable_t ptepage)
 static inline void pgtable_free(void *table, unsigned index_size)
 {
 	if (!index_size) {
+		pgtable_page_dtor(virt_to_page(table));
 		free_page((unsigned long)table);
 	} else {
 		BUG_ON(index_size > MAX_PGTABLE_INDEX_SIZE);

diff --git a/arch/powerpc/include/asm/nohash/32/pgalloc.h b/arch/powerpc/include/asm/nohash/32/pgalloc.h
index 29d37bd1f3b3..1707781d2f20 100644
--- a/arch/powerpc/include/asm/nohash/32/pgalloc.h
+++ b/arch/powerpc/include/asm/nohash/32/pgalloc.h

@@ -100,6 +100,7 @@ static inline void pte_free(struct mm_struct *mm, pgtable_t ptepage)
 static inline void pgtable_free(void *table, unsigned index_size)
 {
 	if (!index_size) {
+		pgtable_page_dtor(virt_to_page(table));
 		free_page((unsigned long)table);
 	} else {
 		BUG_ON(index_size > MAX_PGTABLE_INDEX_SIZE);

diff --git a/arch/powerpc/include/asm/nohash/64/pgalloc.h b/arch/powerpc/include/asm/nohash/64/pgalloc.h
index 21624ff1f065..0e693f322cb2 100644
--- a/arch/powerpc/include/asm/nohash/64/pgalloc.h
+++ b/arch/powerpc/include/asm/nohash/64/pgalloc.h

@@ -133,7 +133,7 @@ static inline void pte_free(struct mm_struct *mm, pgtable_t ptepage)
 static inline void pgtable_free(void *table, int shift)
 {
 	if (!shift) {
-		pgtable_page_dtor(table);
+		pgtable_page_dtor(virt_to_page(table));
 		free_page((unsigned long)table);
 	} else {
 		BUG_ON(shift > MAX_PGTABLE_INDEX_SIZE);

-- 
2.17.0

Re: powerpc/mm: Fix kernel crash on page table free

From: Michael Ellerman <hidden>
Date: 2018-06-01 15:55:03

On Wed, 2018-05-30 at 12:32:25 UTC, "Aneesh Kumar K.V" wrote:

Fix the below crash on BookE 64. pgtable_page_dtor expects struct page *arg.

Also call the destructor on non book3s platforms correctly. This free up the
split ptl locks correctly if we had allocated them before.

Call Trace:
[c0000000f30c7520] [c00000000021eeec] .kmem_cache_free+0x9c/0x44c (unreliable)
[c0000000f30c75c0] [c0000000001ee07c] .ptlock_free+0x1c/0x30
[c0000000f30c7630] [c0000000001ee260] .tlb_remove_table+0xdc/0x224
[c0000000f30c76c0] [c0000000001ee640] .free_pgd_range+0x298/0x500
[c0000000f30c77d0] [c000000000232afc] .shift_arg_pages+0x10c/0x1e0
[c0000000f30c7910] [c000000000232dd0] .setup_arg_pages+0x200/0x25c
[c0000000f30c79c0] [c0000000002ad4fc] .load_elf_binary+0x450/0x16c8
[c0000000f30c7b10] [c000000000234914] .search_binary_handler.part.11+0x9c/0x248
[c0000000f30c7bb0] [c00000000023595c] .do_execveat_common.isra.13+0x868/0xc18
[c0000000f30c7cb0] [c00000000000184c] .run_init_process+0x34/0x4c
[c0000000f30c7d30] [c000000000001880] .try_to_run_init_process+0x1c/0x68
[c0000000f30c7db0] [c000000000002bd8] .kernel_init+0xdc/0x130
[c0000000f30c7e30] [c0000000000009dc] .ret_from_kernel_thread+0x58/0x7c

Fixes: 702346768 ("powerpc/mm/nohash: Remove pte fragment dependency from nohash")
Signed-off-by: Aneesh Kumar K.V <redacted>

Applied to powerpc next, thanks.

https://git.kernel.org/powerpc/c/667416f38554eef94485496f3a27b9

cheers

Re: [PATCH] powerpc/mm: Fix kernel crash on page table free

From: Christophe Leroy <hidden>
Date: 2018-06-15 09:35:21


On 05/30/2018 12:32 PM, Aneesh Kumar K.V wrote:

quoted hunk

Fix the below crash on BookE 64. pgtable_page_dtor expects struct page *arg.

Also call the destructor on non book3s platforms correctly. This free up the
split ptl locks correctly if we had allocated them before.

Call Trace:
[c0000000f30c7520] [c00000000021eeec] .kmem_cache_free+0x9c/0x44c (unreliable)
[c0000000f30c75c0] [c0000000001ee07c] .ptlock_free+0x1c/0x30
[c0000000f30c7630] [c0000000001ee260] .tlb_remove_table+0xdc/0x224
[c0000000f30c76c0] [c0000000001ee640] .free_pgd_range+0x298/0x500
[c0000000f30c77d0] [c000000000232afc] .shift_arg_pages+0x10c/0x1e0
[c0000000f30c7910] [c000000000232dd0] .setup_arg_pages+0x200/0x25c
[c0000000f30c79c0] [c0000000002ad4fc] .load_elf_binary+0x450/0x16c8
[c0000000f30c7b10] [c000000000234914] .search_binary_handler.part.11+0x9c/0x248
[c0000000f30c7bb0] [c00000000023595c] .do_execveat_common.isra.13+0x868/0xc18
[c0000000f30c7cb0] [c00000000000184c] .run_init_process+0x34/0x4c
[c0000000f30c7d30] [c000000000001880] .try_to_run_init_process+0x1c/0x68
[c0000000f30c7db0] [c000000000002bd8] .kernel_init+0xdc/0x130
[c0000000f30c7e30] [c0000000000009dc] .ret_from_kernel_thread+0x58/0x7c

Fixes: 702346768 ("powerpc/mm/nohash: Remove pte fragment dependency from nohash")
Signed-off-by: Aneesh Kumar K.V <redacted>
---
  arch/powerpc/include/asm/book3s/32/pgalloc.h | 1 +
  arch/powerpc/include/asm/nohash/32/pgalloc.h | 1 +
  arch/powerpc/include/asm/nohash/64/pgalloc.h | 2 +-
  3 files changed, 3 insertions(+), 1 deletion(-)

diff --git a/arch/powerpc/include/asm/book3s/32/pgalloc.h b/arch/powerpc/include/asm/book3s/32/pgalloc.h
index 5073cc75f1c8..6a6673907e45 100644
--- a/arch/powerpc/include/asm/book3s/32/pgalloc.h
+++ b/arch/powerpc/include/asm/book3s/32/pgalloc.h

@@ -99,6 +99,7 @@ static inline void pte_free(struct mm_struct *mm, pgtable_t ptepage)
  static inline void pgtable_free(void *table, unsigned index_size)
  {
  	if (!index_size) {
+		pgtable_page_dtor(virt_to_page(table));

__pte_free_tlb() already calls pgtable_page_dtor(table) before calling
pgtable_free() via pgtable_free_tlb().

Is it normal to call it twice ?

quoted hunk

  		free_page((unsigned long)table);
  	} else {
  		BUG_ON(index_size > MAX_PGTABLE_INDEX_SIZE);

diff --git a/arch/powerpc/include/asm/nohash/32/pgalloc.h b/arch/powerpc/include/asm/nohash/32/pgalloc.h
index 29d37bd1f3b3..1707781d2f20 100644
--- a/arch/powerpc/include/asm/nohash/32/pgalloc.h
+++ b/arch/powerpc/include/asm/nohash/32/pgalloc.h

@@ -100,6 +100,7 @@ static inline void pte_free(struct mm_struct *mm, pgtable_t ptepage)
  static inline void pgtable_free(void *table, unsigned index_size)
  {
  	if (!index_size) {
+		pgtable_page_dtor(virt_to_page(table));

Same here

Christophe

quoted hunk

  		free_page((unsigned long)table);
  	} else {
  		BUG_ON(index_size > MAX_PGTABLE_INDEX_SIZE);

diff --git a/arch/powerpc/include/asm/nohash/64/pgalloc.h b/arch/powerpc/include/asm/nohash/64/pgalloc.h
index 21624ff1f065..0e693f322cb2 100644
--- a/arch/powerpc/include/asm/nohash/64/pgalloc.h
+++ b/arch/powerpc/include/asm/nohash/64/pgalloc.h

@@ -133,7 +133,7 @@ static inline void pte_free(struct mm_struct *mm, pgtable_t ptepage)
  static inline void pgtable_free(void *table, int shift)
  {
  	if (!shift) {
-		pgtable_page_dtor(table);
+		pgtable_page_dtor(virt_to_page(table));
  		free_page((unsigned long)table);
  	} else {
  		BUG_ON(shift > MAX_PGTABLE_INDEX_SIZE);

Re: [PATCH] powerpc/mm: Fix kernel crash on page table free

From: Aneesh Kumar K.V <hidden>
Date: 2018-06-15 10:15:34

On 06/15/2018 03:24 AM, Christophe Leroy wrote:


On 05/30/2018 12:32 PM, Aneesh Kumar K.V wrote:

quoted

Fix the below crash on BookE 64. pgtable_page_dtor expects struct page 
*arg.

Also call the destructor on non book3s platforms correctly. This free 
up the
split ptl locks correctly if we had allocated them before.

Call Trace:
[c0000000f30c7520] [c00000000021eeec] .kmem_cache_free+0x9c/0x44c 
(unreliable)
[c0000000f30c75c0] [c0000000001ee07c] .ptlock_free+0x1c/0x30
[c0000000f30c7630] [c0000000001ee260] .tlb_remove_table+0xdc/0x224
[c0000000f30c76c0] [c0000000001ee640] .free_pgd_range+0x298/0x500
[c0000000f30c77d0] [c000000000232afc] .shift_arg_pages+0x10c/0x1e0
[c0000000f30c7910] [c000000000232dd0] .setup_arg_pages+0x200/0x25c
[c0000000f30c79c0] [c0000000002ad4fc] .load_elf_binary+0x450/0x16c8
[c0000000f30c7b10] [c000000000234914] 
.search_binary_handler.part.11+0x9c/0x248
[c0000000f30c7bb0] [c00000000023595c] 
.do_execveat_common.isra.13+0x868/0xc18
[c0000000f30c7cb0] [c00000000000184c] .run_init_process+0x34/0x4c
[c0000000f30c7d30] [c000000000001880] .try_to_run_init_process+0x1c/0x68
[c0000000f30c7db0] [c000000000002bd8] .kernel_init+0xdc/0x130
[c0000000f30c7e30] [c0000000000009dc] .ret_from_kernel_thread+0x58/0x7c

Fixes: 702346768 ("powerpc/mm/nohash: Remove pte fragment dependency 
from nohash")
Signed-off-by: Aneesh Kumar K.V <redacted>
---
  arch/powerpc/include/asm/book3s/32/pgalloc.h | 1 +
  arch/powerpc/include/asm/nohash/32/pgalloc.h | 1 +
  arch/powerpc/include/asm/nohash/64/pgalloc.h | 2 +-
  3 files changed, 3 insertions(+), 1 deletion(-)

diff --git a/arch/powerpc/include/asm/book3s/32/pgalloc.h

b/arch/powerpc/include/asm/book3s/32/pgalloc.h
index 5073cc75f1c8..6a6673907e45 100644

--- a/arch/powerpc/include/asm/book3s/32/pgalloc.h
+++ b/arch/powerpc/include/asm/book3s/32/pgalloc.h

@@ -99,6 +99,7 @@ static inline void pte_free(struct mm_struct *mm,

pgtable_t ptepage)
  static inline void pgtable_free(void *table, unsigned index_size)
  {
      if (!index_size) {
+        pgtable_page_dtor(virt_to_page(table));

__pte_free_tlb() already calls pgtable_page_dtor(table) before calling
pgtable_free() via pgtable_free_tlb().

Is it normal to call it twice ?

No. We should call pgtable_page_dtor only in the rcu callback. So we 
should remove it from __pte_free_tlb().

quoted

          free_page((unsigned long)table);
      } else {
          BUG_ON(index_size > MAX_PGTABLE_INDEX_SIZE);

diff --git a/arch/powerpc/include/asm/nohash/32/pgalloc.h

b/arch/powerpc/include/asm/nohash/32/pgalloc.h
index 29d37bd1f3b3..1707781d2f20 100644

--- a/arch/powerpc/include/asm/nohash/32/pgalloc.h
+++ b/arch/powerpc/include/asm/nohash/32/pgalloc.h

@@ -100,6 +100,7 @@ static inline void pte_free(struct mm_struct *mm,

pgtable_t ptepage)
  static inline void pgtable_free(void *table, unsigned index_size)
  {
      if (!index_size) {
+        pgtable_page_dtor(virt_to_page(table));

Same here

I don't have the facility to test anything other than book3s64. Can you 
do a patch for this?

-aneesh

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