* [PATCH v2] arm64: mm: don't use CON and BLK mapping if KFENCE is enabled
@ 2021-05-25 2:45 Jisheng Zhang
2021-05-25 8:51 ` Marco Elver
2021-05-25 14:02 ` Catalin Marinas
0 siblings, 2 replies; 3+ messages in thread
From: Jisheng Zhang @ 2021-05-25 2:45 UTC (permalink / raw)
To: Catalin Marinas, Will Deacon, Mark Rutland, Marco Elver
Cc: Alexander Potapenko, linux-arm-kernel, linux-kernel, stable
When we added KFENCE support for arm64, we intended that it would
force the entire linear map to be mapped at page granularity, but we
only enforced this in arch_add_memory() and not in map_mem(), so
memory mapped at boot time can be mapped at a larger granularity.
When booting a kernel with KFENCE=y and RODATA_FULL=n, this results in
the following WARNING at boot:
[ 0.000000] ------------[ cut here ]------------
[ 0.000000] WARNING: CPU: 0 PID: 0 at mm/memory.c:2462 apply_to_pmd_range+0xec/0x190
[ 0.000000] CPU: 0 PID: 0 Comm: swapper/0 Not tainted 5.13.0-rc1+ #10
[ 0.000000] Hardware name: linux,dummy-virt (DT)
[ 0.000000] pstate: 600000c5 (nZCv daIF -PAN -UAO -TCO BTYPE=--)
[ 0.000000] pc : apply_to_pmd_range+0xec/0x190
[ 0.000000] lr : __apply_to_page_range+0x94/0x170
[ 0.000000] sp : ffffffc010573e20
[ 0.000000] x29: ffffffc010573e20 x28: ffffff801f400000 x27: ffffff801f401000
[ 0.000000] x26: 0000000000000001 x25: ffffff801f400fff x24: ffffffc010573f28
[ 0.000000] x23: ffffffc01002b710 x22: ffffffc0105fa450 x21: ffffffc010573ee4
[ 0.000000] x20: ffffff801fffb7d0 x19: ffffff801f401000 x18: 00000000fffffffe
[ 0.000000] x17: 000000000000003f x16: 000000000000000a x15: ffffffc01060b940
[ 0.000000] x14: 0000000000000000 x13: 0098968000000000 x12: 0000000098968000
[ 0.000000] x11: 0000000000000000 x10: 0000000098968000 x9 : 0000000000000001
[ 0.000000] x8 : 0000000000000000 x7 : ffffffc010573ee4 x6 : 0000000000000001
[ 0.000000] x5 : ffffffc010573f28 x4 : ffffffc01002b710 x3 : 0000000040000000
[ 0.000000] x2 : ffffff801f5fffff x1 : 0000000000000001 x0 : 007800005f400705
[ 0.000000] Call trace:
[ 0.000000] apply_to_pmd_range+0xec/0x190
[ 0.000000] __apply_to_page_range+0x94/0x170
[ 0.000000] apply_to_page_range+0x10/0x20
[ 0.000000] __change_memory_common+0x50/0xdc
[ 0.000000] set_memory_valid+0x30/0x40
[ 0.000000] kfence_init_pool+0x9c/0x16c
[ 0.000000] kfence_init+0x20/0x98
[ 0.000000] start_kernel+0x284/0x3f8
Fixes: 840b23986344 ("arm64, kfence: enable KFENCE for ARM64")
Cc: <stable@vger.kernel.org> # 5.12.x
Signed-off-by: Jisheng Zhang <Jisheng.Zhang@synaptics.com>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Marco Elver <elver@google.com>
---
Since v1:
- improve commit msg as Mark suggested
- add "Cc: stable@vger.kernel.org"
- collect Mark and Marco's Acks
arch/arm64/mm/mmu.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c
index 6dd9369e3ea0..89b66ef43a0f 100644
--- a/arch/arm64/mm/mmu.c
+++ b/arch/arm64/mm/mmu.c
@@ -515,7 +515,8 @@ static void __init map_mem(pgd_t *pgdp)
*/
BUILD_BUG_ON(pgd_index(direct_map_end - 1) == pgd_index(direct_map_end));
- if (rodata_full || crash_mem_map || debug_pagealloc_enabled())
+ if (rodata_full || crash_mem_map || debug_pagealloc_enabled() ||
+ IS_ENABLED(CONFIG_KFENCE))
flags |= NO_BLOCK_MAPPINGS | NO_CONT_MAPPINGS;
/*
--
2.31.0
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH v2] arm64: mm: don't use CON and BLK mapping if KFENCE is enabled
2021-05-25 2:45 [PATCH v2] arm64: mm: don't use CON and BLK mapping if KFENCE is enabled Jisheng Zhang
@ 2021-05-25 8:51 ` Marco Elver
2021-05-25 14:02 ` Catalin Marinas
1 sibling, 0 replies; 3+ messages in thread
From: Marco Elver @ 2021-05-25 8:51 UTC (permalink / raw)
To: Jisheng Zhang
Cc: Catalin Marinas, Will Deacon, Mark Rutland, Alexander Potapenko,
Linux ARM, LKML, stable
On Tue, 25 May 2021 at 04:46, Jisheng Zhang <Jisheng.Zhang@synaptics.com> wrote:
> When we added KFENCE support for arm64, we intended that it would
> force the entire linear map to be mapped at page granularity, but we
> only enforced this in arch_add_memory() and not in map_mem(), so
> memory mapped at boot time can be mapped at a larger granularity.
>
> When booting a kernel with KFENCE=y and RODATA_FULL=n, this results in
> the following WARNING at boot:
>
> [ 0.000000] ------------[ cut here ]------------
> [ 0.000000] WARNING: CPU: 0 PID: 0 at mm/memory.c:2462 apply_to_pmd_range+0xec/0x190
> [ 0.000000] CPU: 0 PID: 0 Comm: swapper/0 Not tainted 5.13.0-rc1+ #10
> [ 0.000000] Hardware name: linux,dummy-virt (DT)
> [ 0.000000] pstate: 600000c5 (nZCv daIF -PAN -UAO -TCO BTYPE=--)
> [ 0.000000] pc : apply_to_pmd_range+0xec/0x190
> [ 0.000000] lr : __apply_to_page_range+0x94/0x170
> [ 0.000000] sp : ffffffc010573e20
> [ 0.000000] x29: ffffffc010573e20 x28: ffffff801f400000 x27: ffffff801f401000
> [ 0.000000] x26: 0000000000000001 x25: ffffff801f400fff x24: ffffffc010573f28
> [ 0.000000] x23: ffffffc01002b710 x22: ffffffc0105fa450 x21: ffffffc010573ee4
> [ 0.000000] x20: ffffff801fffb7d0 x19: ffffff801f401000 x18: 00000000fffffffe
> [ 0.000000] x17: 000000000000003f x16: 000000000000000a x15: ffffffc01060b940
> [ 0.000000] x14: 0000000000000000 x13: 0098968000000000 x12: 0000000098968000
> [ 0.000000] x11: 0000000000000000 x10: 0000000098968000 x9 : 0000000000000001
> [ 0.000000] x8 : 0000000000000000 x7 : ffffffc010573ee4 x6 : 0000000000000001
> [ 0.000000] x5 : ffffffc010573f28 x4 : ffffffc01002b710 x3 : 0000000040000000
> [ 0.000000] x2 : ffffff801f5fffff x1 : 0000000000000001 x0 : 007800005f400705
> [ 0.000000] Call trace:
> [ 0.000000] apply_to_pmd_range+0xec/0x190
> [ 0.000000] __apply_to_page_range+0x94/0x170
> [ 0.000000] apply_to_page_range+0x10/0x20
> [ 0.000000] __change_memory_common+0x50/0xdc
> [ 0.000000] set_memory_valid+0x30/0x40
> [ 0.000000] kfence_init_pool+0x9c/0x16c
> [ 0.000000] kfence_init+0x20/0x98
> [ 0.000000] start_kernel+0x284/0x3f8
>
> Fixes: 840b23986344 ("arm64, kfence: enable KFENCE for ARM64")
> Cc: <stable@vger.kernel.org> # 5.12.x
> Signed-off-by: Jisheng Zhang <Jisheng.Zhang@synaptics.com>
> Acked-by: Mark Rutland <mark.rutland@arm.com>
> Acked-by: Marco Elver <elver@google.com>
Tested-by: Marco Elver <elver@google.com>
Thank you.
> ---
> Since v1:
> - improve commit msg as Mark suggested
> - add "Cc: stable@vger.kernel.org"
> - collect Mark and Marco's Acks
>
> arch/arm64/mm/mmu.c | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c
> index 6dd9369e3ea0..89b66ef43a0f 100644
> --- a/arch/arm64/mm/mmu.c
> +++ b/arch/arm64/mm/mmu.c
> @@ -515,7 +515,8 @@ static void __init map_mem(pgd_t *pgdp)
> */
> BUILD_BUG_ON(pgd_index(direct_map_end - 1) == pgd_index(direct_map_end));
>
> - if (rodata_full || crash_mem_map || debug_pagealloc_enabled())
> + if (rodata_full || crash_mem_map || debug_pagealloc_enabled() ||
> + IS_ENABLED(CONFIG_KFENCE))
> flags |= NO_BLOCK_MAPPINGS | NO_CONT_MAPPINGS;
>
> /*
> --
> 2.31.0
>
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH v2] arm64: mm: don't use CON and BLK mapping if KFENCE is enabled
2021-05-25 2:45 [PATCH v2] arm64: mm: don't use CON and BLK mapping if KFENCE is enabled Jisheng Zhang
2021-05-25 8:51 ` Marco Elver
@ 2021-05-25 14:02 ` Catalin Marinas
1 sibling, 0 replies; 3+ messages in thread
From: Catalin Marinas @ 2021-05-25 14:02 UTC (permalink / raw)
To: Marco Elver, Jisheng Zhang, Mark Rutland, Will Deacon
Cc: linux-arm-kernel, stable, linux-kernel, Alexander Potapenko
On Tue, 25 May 2021 10:45:51 +0800, Jisheng Zhang wrote:
> When we added KFENCE support for arm64, we intended that it would
> force the entire linear map to be mapped at page granularity, but we
> only enforced this in arch_add_memory() and not in map_mem(), so
> memory mapped at boot time can be mapped at a larger granularity.
>
> When booting a kernel with KFENCE=y and RODATA_FULL=n, this results in
> the following WARNING at boot:
>
> [...]
Applied to arm64 (for-next/fixes), thanks!
[1/1] arm64: mm: don't use CON and BLK mapping if KFENCE is enabled
https://git.kernel.org/arm64/c/e69012400b0c
--
Catalin
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
^ permalink raw reply [flat|nested] 3+ messages in thread
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2021-05-25 8:51 ` Marco Elver
2021-05-25 14:02 ` Catalin Marinas
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