Re: [PATCH RFC RFT v2 1/5] mm: Introduce ARCH_HAS_USER_SHADOW_STACK

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On Tue, Nov 14, 2023 at 08:05:54PM +0000, Mark Brown wrote:
Since multiple architectures have support for shadow stacks and we need to
select support for this feature in several places in the generic code
provide a generic config option that the architectures can select.

Suggested-by: David Hildenbrand <david@xxxxxxxxxx>
Signed-off-by: Mark Brown <broonie@xxxxxxxxxx>
---
arch/x86/Kconfig   | 1 +
fs/proc/task_mmu.c | 2 +-
include/linux/mm.h | 2 +-
mm/Kconfig         | 6 ++++++
4 files changed, 9 insertions(+), 2 deletions(-)

diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 3762f41bb092..14b7703a9a2b 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -1952,6 +1952,7 @@ config X86_USER_SHADOW_STACK
	depends on AS_WRUSS
	depends on X86_64
	select ARCH_USES_HIGH_VMA_FLAGS
+	select ARCH_HAS_USER_SHADOW_STACK
	select X86_CET
	help
	  Shadow stack protection is a hardware feature that detects function
diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c
index ef2eb12906da..f0a904aeee8e 100644
--- a/fs/proc/task_mmu.c
+++ b/fs/proc/task_mmu.c
@@ -699,7 +699,7 @@ static void show_smap_vma_flags(struct seq_file *m, struct vm_area_struct *vma)
#ifdef CONFIG_HAVE_ARCH_USERFAULTFD_MINOR
		[ilog2(VM_UFFD_MINOR)]	= "ui",
#endif /* CONFIG_HAVE_ARCH_USERFAULTFD_MINOR */
-#ifdef CONFIG_X86_USER_SHADOW_STACK
+#ifdef CONFIG_ARCH_HAS_USER_SHADOW_STACK
		[ilog2(VM_SHADOW_STACK)] = "ss",
#endif
	};
diff --git a/include/linux/mm.h b/include/linux/mm.h
index 418d26608ece..10462f354614 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -341,7 +341,7 @@ extern unsigned int kobjsize(const void *objp);
#endif
#endif /* CONFIG_ARCH_HAS_PKEYS */

-#ifdef CONFIG_X86_USER_SHADOW_STACK
+#ifdef CONFIG_ARCH_HAS_USER_SHADOW_STACK
/*
 * VM_SHADOW_STACK should not be set with VM_SHARED because of lack of
 * support core mm.
diff --git a/mm/Kconfig b/mm/Kconfig
index 89971a894b60..b8638da636e1 100644
--- a/mm/Kconfig
+++ b/mm/Kconfig
@@ -1270,6 +1270,12 @@ config LOCK_MM_AND_FIND_VMA
	bool
	depends on !STACK_GROWSUP

+config ARCH_HAS_USER_SHADOW_STACK
+	bool
+	help
+	  The architecture has hardware support for userspace shadow call
+          stacks (eg, x86 CET, arm64 GCS, RISC-V Zisslpcfi).

Minor correction for future version.RISC-V choose to split extension [1, 2].
It's now:

Zicfiss - CFI using shadow stack
Zicfilp - CFI using landing pad

So for shadow stack purposes, we can start saying "RISC-V Zicfiss"

[1] - https://lists.riscv.org/g/tech-ss-lp-cfi/message/55
[2] - https://github.com/riscv/riscv-cfi/pull/126

+
source "mm/damon/Kconfig"

endmenu

--
2.30.2





[Index of Archives]     [Linux Wireless]     [Linux Kernel]     [ATH6KL]     [Linux Bluetooth]     [Linux Netdev]     [Kernel Newbies]     [Share Photos]     [IDE]     [Security]     [Git]     [Netfilter]     [Bugtraq]     [Yosemite News]     [MIPS Linux]     [ARM Linux]     [Linux Security]     [Linux RAID]     [Linux ATA RAID]     [Samba]     [Device Mapper]

  Powered by Linux