From: Rohan McLure <rmclure@linux.ibm.com>
To: linuxppc-dev@lists.ozlabs.org
Cc: Rohan McLure <rmclure@linux.ibm.com>
Subject: [PATCH 21/23] powerpc/64: Add INTERRUPT_SANITIZE_REGISTERS Kconfig
Date: Fri, 16 Sep 2022 15:32:58 +1000 [thread overview]
Message-ID: <20220916053300.786330-22-rmclure@linux.ibm.com> (raw)
In-Reply-To: <20220916053300.786330-1-rmclure@linux.ibm.com>
Add Kconfig option for enabling clearing of registers on arrival in an
interrupt handler. This reduces the speculation influence of registers
on kernel internals. The option will be consumed by 64-bit systems that
feature speculation and wish to implement this mitigation.
This patch only introduces the Kconfig option, no actual mitigations.
The primary overhead of this mitigation lies in an increased number of
registers that must be saved and restored by interrupt handlers on
Book3S systems. Enable by default on Book3E systems, which prior to
this patch eagerly save and restore register state, meaning that the
mitigation when implemented will have minimal overhead.
Signed-off-by: Rohan McLure <rmclure@linux.ibm.com>
---
V4 -> V5: New patch
---
arch/powerpc/Kconfig | 9 +++++++++
1 file changed, 9 insertions(+)
diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index ef6c83e79c9b..a643ebd83349 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -528,6 +528,15 @@ config HOTPLUG_CPU
Say N if you are unsure.
+config INTERRUPT_SANITIZE_REGISTERS
+ bool "Clear gprs on interrupt arrival"
+ depends on PPC64 && ARCH_HAS_SYSCALL_WRAPPER
+ default PPC_BOOK3E_64
+ help
+ Reduce the influence of user register state on interrupt handlers and
+ syscalls through clearing user state from registers before handling
+ the exception.
+
config PPC_QUEUED_SPINLOCKS
bool "Queued spinlocks" if EXPERT
depends on SMP
--
2.34.1
next prev parent reply other threads:[~2022-09-16 5:42 UTC|newest]
Thread overview: 46+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-09-16 5:32 [PATCH 00/23] powerpc: Syscall wrapper and register clearing Rohan McLure
2022-09-16 5:32 ` [PATCH 01/23] powerpc: Remove asmlinkage from syscall handler definitions Rohan McLure
2022-09-16 5:32 ` [PATCH 02/23] powerpc: Save caller r3 prior to system_call_exception Rohan McLure
2022-09-16 5:32 ` [PATCH 03/23] powerpc: Add ZEROIZE_GPRS macros for register clears Rohan McLure
2022-09-16 5:32 ` [PATCH 04/23] powerpc/64s: Use {ZEROIZE,SAVE,REST}_GPRS macros in sc, scv 0 handlers Rohan McLure
2022-09-16 5:32 ` [PATCH 05/23] powerpc/32: Clarify interrupt restores with REST_GPR macro in entry_32.S Rohan McLure
2022-09-20 0:51 ` Nicholas Piggin
2022-09-16 5:32 ` [PATCH 06/23] powerpc/64e: Clarify register saves and clears with {SAVE,ZEROIZE}_GPRS Rohan McLure
2022-09-20 0:55 ` Nicholas Piggin
2022-09-16 5:32 ` [PATCH 07/23] powerpc/64s: Fix comment on interrupt handler prologue Rohan McLure
2022-09-20 0:55 ` Nicholas Piggin
2022-09-16 5:32 ` [PATCH 08/23] powerpc: Fix fallocate and fadvise64_64 compat parameter combination Rohan McLure
2022-09-16 6:54 ` Arnd Bergmann
2022-09-20 1:01 ` Nicholas Piggin
2022-09-16 5:32 ` [PATCH 09/23] asm-generic: compat: Support BE for long long args in 32-bit ABIs Rohan McLure
2022-09-20 1:06 ` Nicholas Piggin
2022-09-20 7:09 ` Arnd Bergmann
2022-09-16 5:32 ` [PATCH 10/23] powerpc: Use generic fallocate compatibility syscall Rohan McLure
2022-09-16 6:56 ` Arnd Bergmann
2022-09-16 5:32 ` [PATCH 11/23] powerpc/32: Remove powerpc select specialisation Rohan McLure
2022-09-16 5:32 ` [PATCH 12/23] powerpc: Remove direct call to personality syscall handler Rohan McLure
2022-09-16 5:32 ` [PATCH 13/23] powerpc: Remove direct call to mmap2 syscall handlers Rohan McLure
2022-09-16 5:32 ` [PATCH 14/23] powerpc: Provide do_ppc64_personality helper Rohan McLure
2022-09-16 5:32 ` [PATCH 15/23] powerpc: Adopt SYSCALL_DEFINE for arch-specific syscall handlers Rohan McLure
2022-09-16 5:48 ` Rohan McLure
2022-09-20 1:24 ` Nicholas Piggin
2022-09-16 5:32 ` [PATCH 16/23] powerpc: Include all arch-specific syscall prototypes Rohan McLure
2022-09-20 1:27 ` Nicholas Piggin
2022-09-16 5:32 ` [PATCH 17/23] powerpc: Enable compile-time check for syscall handlers Rohan McLure
2022-09-20 1:30 ` Nicholas Piggin
2022-09-16 5:32 ` [PATCH 18/23] powerpc: Use common syscall handler type Rohan McLure
2022-09-20 1:39 ` Nicholas Piggin
2022-09-16 5:32 ` [PATCH 19/23] powerpc: Provide syscall wrapper Rohan McLure
2022-09-20 1:59 ` Nicholas Piggin
2022-09-21 3:44 ` Rohan McLure
2022-09-16 5:32 ` [PATCH 20/23] powerpc/64s: Clear/restore caller gprs in syscall interrupt/return Rohan McLure
2022-09-20 2:03 ` Nicholas Piggin
2022-09-20 4:54 ` Rohan McLure
2022-09-21 5:33 ` Rohan McLure
2022-09-20 2:07 ` Nicholas Piggin
2022-09-16 5:32 ` Rohan McLure [this message]
2022-09-20 2:10 ` [PATCH 21/23] powerpc/64: Add INTERRUPT_SANITIZE_REGISTERS Kconfig Nicholas Piggin
2022-09-16 5:32 ` [PATCH 22/23] powerpc/64s: Clear gprs on interrupt routine entry in Book3S Rohan McLure
2022-09-20 2:27 ` Nicholas Piggin
2022-09-16 5:33 ` [PATCH 23/23] powerpc/64e: Clear gprs on interrupt routine entry on Book3E Rohan McLure
2022-09-16 5:58 ` [PATCH 00/23] powerpc: Syscall wrapper and register clearing Rohan McLure
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