linux-kernel - [PATCH 28/33] x86, pkeys: add arch_validate

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20160212210232.774EEAAB@viggo.jf.intel.com>
Date:	Fri, 12 Feb 2016 13:02:32 -0800
From:	Dave Hansen <dave@...1.net>
To:	linux-kernel@...r.kernel.org
Cc:	linux-mm@...ck.org, x86@...nel.org, torvalds@...ux-foundation.org,
	Dave Hansen <dave@...1.net>, dave.hansen@...ux.intel.com
Subject: [PATCH 28/33] x86, pkeys: add arch_validate_pkey()


From: Dave Hansen <dave.hansen@...ux.intel.com>

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@...ux.intel.com>
Reviewed-by: Thomas Gleixner <tglx@...utronix.de>
---

 b/arch/x86/Kconfig             |    1 +
 b/arch/x86/include/asm/pkeys.h |    6 ++++++
 b/include/linux/pkeys.h        |   25 +++++++++++++++++++++++++
 b/mm/Kconfig                   |    2 ++
 4 files changed, 34 insertions(+)

diff -puN /dev/null arch/x86/include/asm/pkeys.h
--- /dev/null	2015-12-10 15:28:13.322405854 -0800
+++ b/arch/x86/include/asm/pkeys.h	2016-02-12 10:44:26.560718780 -0800
@@ -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 -puN arch/x86/Kconfig~pkeys-71-arch_validate_pkey arch/x86/Kconfig
--- a/arch/x86/Kconfig~pkeys-71-arch_validate_pkey	2016-02-12 10:44:26.555718551 -0800
+++ b/arch/x86/Kconfig	2016-02-12 10:44:26.561718825 -0800
@@ -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 -puN /dev/null include/linux/pkeys.h
--- /dev/null	2015-12-10 15:28:13.322405854 -0800
+++ b/include/linux/pkeys.h	2016-02-12 10:44:26.561718825 -0800
@@ -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 -puN mm/Kconfig~pkeys-71-arch_validate_pkey mm/Kconfig
--- a/mm/Kconfig~pkeys-71-arch_validate_pkey	2016-02-12 10:44:26.557718643 -0800
+++ b/mm/Kconfig	2016-02-12 10:44:26.562718871 -0800
@@ -672,3 +672,5 @@ config FRAME_VECTOR
 
 config ARCH_USES_HIGH_VMA_FLAGS
 	bool
+config ARCH_HAS_PKEYS
+	bool
_