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authorDave Hansen <dave.hansen@linux.intel.com>2016-02-12 13:02:32 -0800
committerIngo Molnar <mingo@kernel.org>2016-02-18 19:46:31 +0100
commit66d375709d2c891acc639538fd3179fa0cbb0daf (patch)
treee4130fdef51a5d4820e8e870d34a42d7b384c9b0
parente6bfb70959a0ca6ddedb29e779a293c6f71ed0e7 (diff)
mm/core, x86/mm/pkeys: Add arch_validate_pkey()
The syscall-level code is passed a protection key and need to return an appropriate error code if the protection key is bogus. We will be using this in subsequent patches. Note that this also begins a series of arch-specific calls that we need to expose in otherwise arch-independent code. We create a linux/pkeys.h header where we will put *all* the stubs for these functions. Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Dave Hansen <dave@sr71.net> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@redhat.com> Cc: linux-mm@kvack.org Link: http://lkml.kernel.org/r/20160212210232.774EEAAB@viggo.jf.intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
-rw-r--r--arch/x86/Kconfig1
-rw-r--r--arch/x86/include/asm/pkeys.h6
-rw-r--r--include/linux/pkeys.h25
-rw-r--r--mm/Kconfig2
4 files changed, 34 insertions, 0 deletions
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index b8754348de4d..eda18cecdbbd 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -156,6 +156,7 @@ config X86
select X86_DEV_DMA_OPS if X86_64
select X86_FEATURE_NAMES if PROC_FS
select ARCH_USES_HIGH_VMA_FLAGS if X86_INTEL_MEMORY_PROTECTION_KEYS
+ select ARCH_HAS_PKEYS if X86_INTEL_MEMORY_PROTECTION_KEYS
config INSTRUCTION_DECODER
def_bool y
diff --git a/arch/x86/include/asm/pkeys.h b/arch/x86/include/asm/pkeys.h
new file mode 100644
index 000000000000..04243c23380c
--- /dev/null
+++ b/arch/x86/include/asm/pkeys.h
@@ -0,0 +1,6 @@
+#ifndef _ASM_X86_PKEYS_H
+#define _ASM_X86_PKEYS_H
+
+#define arch_max_pkey() (boot_cpu_has(X86_FEATURE_OSPKE) ? 16 : 1)
+
+#endif /*_ASM_X86_PKEYS_H */
diff --git a/include/linux/pkeys.h b/include/linux/pkeys.h
new file mode 100644
index 000000000000..55e465f93a28
--- /dev/null
+++ b/include/linux/pkeys.h
@@ -0,0 +1,25 @@
+#ifndef _LINUX_PKEYS_H
+#define _LINUX_PKEYS_H
+
+#include <linux/mm_types.h>
+#include <asm/mmu_context.h>
+
+#ifdef CONFIG_ARCH_HAS_PKEYS
+#include <asm/pkeys.h>
+#else /* ! CONFIG_ARCH_HAS_PKEYS */
+#define arch_max_pkey() (1)
+#endif /* ! CONFIG_ARCH_HAS_PKEYS */
+
+/*
+ * This is called from mprotect_pkey().
+ *
+ * Returns true if the protection keys is valid.
+ */
+static inline bool validate_pkey(int pkey)
+{
+ if (pkey < 0)
+ return false;
+ return (pkey < arch_max_pkey());
+}
+
+#endif /* _LINUX_PKEYS_H */
diff --git a/mm/Kconfig b/mm/Kconfig
index 6cf439948297..2702bb6c21df 100644
--- a/mm/Kconfig
+++ b/mm/Kconfig
@@ -672,3 +672,5 @@ config FRAME_VECTOR
config ARCH_USES_HIGH_VMA_FLAGS
bool
+config ARCH_HAS_PKEYS
+ bool