2023-09-16 06:21:02

by Kees Cook

Subject: [PATCH] x86/mm/dump_pagetables: Add SLAB_VIRTUAL knowledge

Add the markings for the SLAB_VIRTUAL area.

Cc: Matteo Rizzo <[email protected]>
Cc: Jann Horn <[email protected]>
Cc: Dave Hansen <[email protected]>
Cc: Andy Lutomirski <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Borislav Petkov <[email protected]>
Cc: [email protected]
Cc: "H. Peter Anvin" <[email protected]>
Signed-off-by: Kees Cook <[email protected]>
---
This is on top of the SLAB_VIRTUAL series:
https://lore.kernel.org/all/[email protected]/

Feel free to collapse this into the x86 patch from the above series.

FYI, as expected, the kernel page table entries get way longer with
SLAB_VIRTUAL. :)

Without SLAB_VIRTUAL:

# wc -l /sys/kernel/debug/page_tables/kernel
1501 /sys/kernel/debug/page_tables/kernel

With SLAB_VIRTUAL:

# wc -l /sys/kernel/debug/page_tables/kernel
7549 /sys/kernel/debug/page_tables/kernel
---
arch/x86/mm/dump_pagetables.c | 6 ++++++
1 file changed, 6 insertions(+)

diff --git a/arch/x86/mm/dump_pagetables.c b/arch/x86/mm/dump_pagetables.c
index e1b599ecbbc2..b1fa68669e61 100644
--- a/arch/x86/mm/dump_pagetables.c
+++ b/arch/x86/mm/dump_pagetables.c
@@ -64,6 +64,9 @@ enum address_markers_idx {
KASAN_SHADOW_END_NR,
#endif
CPU_ENTRY_AREA_NR,
+#ifdef CONFIG_SLAB_VIRTUAL
+ SLAB_AREA_NR,
+#endif
#ifdef CONFIG_X86_ESPFIX64
ESPFIX_START_NR,
#endif
@@ -95,6 +98,9 @@ static struct addr_marker address_markers[] = {
[LDT_NR] = { 0UL, "LDT remap" },
#endif
[CPU_ENTRY_AREA_NR] = { CPU_ENTRY_AREA_BASE,"CPU entry Area" },
+#ifdef CONFIG_SLAB_VIRTUAL
+ [SLAB_AREA_NR] = { SLAB_BASE_ADDR, "Slab Area" },
+#endif
#ifdef CONFIG_X86_ESPFIX64
[ESPFIX_START_NR] = { ESPFIX_BASE_ADDR, "ESPfix Area", 16 },
#endif
--
2.34.1

2023-09-18 22:00:22

by Matteo Rizzo

Subject: Re: [PATCH] x86/mm/dump_pagetables: Add SLAB_VIRTUAL knowledge

On Sat, 16 Sept 2023 at 04:18, Kees Cook <[email protected]> wrote:
>
> Add the markings for the SLAB_VIRTUAL area.
>
> Feel free to collapse this into the x86 patch from the above series.

Thanks! I will add it to the next revision of the series.

--
Matteo