X-Git-Url: http://git.monstr.eu/?a=blobdiff_plain;f=arch%2FKconfig;h=c45b770d3579a3ef0ff9e482e452e88f40ade8b8;hb=8db6f937f4e76d9dd23795311fc14f0a5c0ac119;hp=2bb30673d8e6fbd5e7c3d41e8fe0800020c0f779;hpb=6c905ab1ace224e847536f658b7831e458e479dd;p=linux-2.6-microblaze.git

diff --git a/arch/Kconfig b/arch/Kconfig
index 2bb30673d8e6..c45b770d3579 100644
--- a/arch/Kconfig
+++ b/arch/Kconfig
@@ -631,14 +631,12 @@ config ARCH_SUPPORTS_LTO_CLANG_THIN
 config HAS_LTO_CLANG
 	def_bool y
 	# Clang >= 11: https://github.com/ClangBuiltLinux/linux/issues/510
-	depends on CC_IS_CLANG && CLANG_VERSION >= 110000 && LD_IS_LLD
-	depends on $(success,test $(LLVM) -eq 1)
-	depends on $(success,test $(LLVM_IAS) -eq 1)
+	depends on CC_IS_CLANG && CLANG_VERSION >= 110000 && LD_IS_LLD && AS_IS_LLVM
 	depends on $(success,$(NM) --help | head -n 1 | grep -qi llvm)
 	depends on $(success,$(AR) --help | head -n 1 | grep -qi llvm)
 	depends on ARCH_SUPPORTS_LTO_CLANG
 	depends on !FTRACE_MCOUNT_USE_RECORDMCOUNT
-	depends on !KASAN
+	depends on !KASAN || KASAN_HW_TAGS
 	depends on !GCOV_KERNEL
 	help
 	  The compiler and Kconfig options support building with Clang's
@@ -693,6 +691,51 @@ config LTO_CLANG_THIN
 	  If unsure, say Y.
 endchoice
 
+config ARCH_SUPPORTS_CFI_CLANG
+	bool
+	help
+	  An architecture should select this option if it can support Clang's
+	  Control-Flow Integrity (CFI) checking.
+
+config CFI_CLANG
+	bool "Use Clang's Control Flow Integrity (CFI)"
+	depends on LTO_CLANG && ARCH_SUPPORTS_CFI_CLANG
+	# Clang >= 12:
+	# - https://bugs.llvm.org/show_bug.cgi?id=46258
+	# - https://bugs.llvm.org/show_bug.cgi?id=47479
+	depends on CLANG_VERSION >= 120000
+	select KALLSYMS
+	help
+	  This option enables Clang’s forward-edge Control Flow Integrity
+	  (CFI) checking, where the compiler injects a runtime check to each
+	  indirect function call to ensure the target is a valid function with
+	  the correct static type. This restricts possible call targets and
+	  makes it more difficult for an attacker to exploit bugs that allow
+	  the modification of stored function pointers. More information can be
+	  found from Clang's documentation:
+
+	    https://clang.llvm.org/docs/ControlFlowIntegrity.html
+
+config CFI_CLANG_SHADOW
+	bool "Use CFI shadow to speed up cross-module checks"
+	default y
+	depends on CFI_CLANG && MODULES
+	help
+	  If you select this option, the kernel builds a fast look-up table of
+	  CFI check functions in loaded modules to reduce performance overhead.
+
+	  If unsure, say Y.
+
+config CFI_PERMISSIVE
+	bool "Use CFI in permissive mode"
+	depends on CFI_CLANG
+	help
+	  When selected, Control Flow Integrity (CFI) violations result in a
+	  warning instead of a kernel panic. This option should only be used
+	  for finding indirect call type mismatches during development.
+
+	  If unsure, say N.
+
 config HAVE_ARCH_WITHIN_STACK_FRAMES
 	bool
 	help
@@ -786,6 +829,17 @@ config HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD
 config HAVE_ARCH_HUGE_VMAP
 	bool
 
+#
+#  Archs that select this would be capable of PMD-sized vmaps (i.e.,
+#  arch_vmap_pmd_supported() returns true), and they must make no assumptions
+#  that vmalloc memory is mapped with PAGE_SIZE ptes. The VM_NO_HUGE_VMAP flag
+#  can be used to prohibit arch-specific allocations from using hugepages to
+#  help with this (e.g., modules may require it).
+#
+config HAVE_ARCH_HUGE_VMALLOC
+	depends on HAVE_ARCH_HUGE_VMAP
+	bool
+
 config ARCH_WANT_HUGE_PMD_SHARE
 	bool
 
@@ -1014,6 +1068,13 @@ config COMPAT_32BIT_TIME
 config ARCH_NO_PREEMPT
 	bool
 
+config ARCH_EPHEMERAL_INODES
+	def_bool n
+	help
+	  An arch should select this symbol if it doesn't keep track of inode
+	  instances on its own, but instead relies on something else (e.g. the
+	  host kernel for an UML kernel).
+
 config ARCH_SUPPORTS_RT
 	bool
 
@@ -1055,6 +1116,29 @@ config VMAP_STACK
 	  backing virtual mappings with real shadow memory, and KASAN_VMALLOC
 	  must be enabled.
 
+config HAVE_ARCH_RANDOMIZE_KSTACK_OFFSET
+	def_bool n
+	help
+	  An arch should select this symbol if it can support kernel stack
+	  offset randomization with calls to add_random_kstack_offset()
+	  during syscall entry and choose_random_kstack_offset() during
+	  syscall exit. Careful removal of -fstack-protector-strong and
+	  -fstack-protector should also be applied to the entry code and
+	  closely examined, as the artificial stack bump looks like an array
+	  to the compiler, so it will attempt to add canary checks regardless
+	  of the static branch state.
+
+config RANDOMIZE_KSTACK_OFFSET_DEFAULT
+	bool "Randomize kernel stack offset on syscall entry"
+	depends on HAVE_ARCH_RANDOMIZE_KSTACK_OFFSET
+	help
+	  The kernel stack offset can be randomized (after pt_regs) by
+	  roughly 5 bits of entropy, frustrating memory corruption
+	  attacks that depend on stack address determinism or
+	  cross-syscall address exposures. This feature is controlled
+	  by kernel boot param "randomize_kstack_offset=on/off", and this
+	  config chooses the default boot state.
+
 config ARCH_OPTIONAL_KERNEL_RWX
 	def_bool n