diff options
author | Linus Torvalds <torvalds@linux-foundation.org> | 2011-10-28 08:29:07 -0400 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2011-10-28 08:29:07 -0400 |
commit | 8e6d539e0fd0c2124a20a207da70f2af7a9ae52c (patch) | |
tree | 73016c1bdb5005125cdb5d60d48f73ab4300be64 /arch | |
parent | 8237eb946a1a23c600fb289cf8dd3b399b10604e (diff) | |
parent | 49d859d78c5aeb998b6936fcb5f288f78d713489 (diff) |
Merge branch 'x86-rdrand-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
* 'x86-rdrand-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86, random: Verify RDRAND functionality and allow it to be disabled
x86, random: Architectural inlines to get random integers with RDRAND
random: Add support for architectural random hooks
Fix up trivial conflicts in drivers/char/random.c: the architectural
random hooks touched "get_random_int()" that was simplified to use MD5
and not do the keyptr thing any more (see commit 6e5714eaf77d: "net:
Compute protocol sequence numbers and fragment IDs using MD5").
Diffstat (limited to 'arch')
-rw-r--r-- | arch/x86/Kconfig | 9 | ||||
-rw-r--r-- | arch/x86/include/asm/archrandom.h | 75 | ||||
-rw-r--r-- | arch/x86/kernel/cpu/Makefile | 1 | ||||
-rw-r--r-- | arch/x86/kernel/cpu/common.c | 2 | ||||
-rw-r--r-- | arch/x86/kernel/cpu/rdrand.c | 73 |
5 files changed, 160 insertions, 0 deletions
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index 16db864c42b7..77f7a384c0b5 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig | |||
@@ -1454,6 +1454,15 @@ config ARCH_USES_PG_UNCACHED | |||
1454 | def_bool y | 1454 | def_bool y |
1455 | depends on X86_PAT | 1455 | depends on X86_PAT |
1456 | 1456 | ||
1457 | config ARCH_RANDOM | ||
1458 | def_bool y | ||
1459 | prompt "x86 architectural random number generator" if EXPERT | ||
1460 | ---help--- | ||
1461 | Enable the x86 architectural RDRAND instruction | ||
1462 | (Intel Bull Mountain technology) to generate random numbers. | ||
1463 | If supported, this is a high bandwidth, cryptographically | ||
1464 | secure hardware random number generator. | ||
1465 | |||
1457 | config EFI | 1466 | config EFI |
1458 | bool "EFI runtime service support" | 1467 | bool "EFI runtime service support" |
1459 | depends on ACPI | 1468 | depends on ACPI |
diff --git a/arch/x86/include/asm/archrandom.h b/arch/x86/include/asm/archrandom.h new file mode 100644 index 000000000000..0d9ec770f2f8 --- /dev/null +++ b/arch/x86/include/asm/archrandom.h | |||
@@ -0,0 +1,75 @@ | |||
1 | /* | ||
2 | * This file is part of the Linux kernel. | ||
3 | * | ||
4 | * Copyright (c) 2011, Intel Corporation | ||
5 | * Authors: Fenghua Yu <fenghua.yu@intel.com>, | ||
6 | * H. Peter Anvin <hpa@linux.intel.com> | ||
7 | * | ||
8 | * This program is free software; you can redistribute it and/or modify it | ||
9 | * under the terms and conditions of the GNU General Public License, | ||
10 | * version 2, as published by the Free Software Foundation. | ||
11 | * | ||
12 | * This program is distributed in the hope it will be useful, but WITHOUT | ||
13 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or | ||
14 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for | ||
15 | * more details. | ||
16 | * | ||
17 | * You should have received a copy of the GNU General Public License along with | ||
18 | * this program; if not, write to the Free Software Foundation, Inc., | ||
19 | * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA. | ||
20 | * | ||
21 | */ | ||
22 | |||
23 | #ifndef ASM_X86_ARCHRANDOM_H | ||
24 | #define ASM_X86_ARCHRANDOM_H | ||
25 | |||
26 | #include <asm/processor.h> | ||
27 | #include <asm/cpufeature.h> | ||
28 | #include <asm/alternative.h> | ||
29 | #include <asm/nops.h> | ||
30 | |||
31 | #define RDRAND_RETRY_LOOPS 10 | ||
32 | |||
33 | #define RDRAND_INT ".byte 0x0f,0xc7,0xf0" | ||
34 | #ifdef CONFIG_X86_64 | ||
35 | # define RDRAND_LONG ".byte 0x48,0x0f,0xc7,0xf0" | ||
36 | #else | ||
37 | # define RDRAND_LONG RDRAND_INT | ||
38 | #endif | ||
39 | |||
40 | #ifdef CONFIG_ARCH_RANDOM | ||
41 | |||
42 | #define GET_RANDOM(name, type, rdrand, nop) \ | ||
43 | static inline int name(type *v) \ | ||
44 | { \ | ||
45 | int ok; \ | ||
46 | alternative_io("movl $0, %0\n\t" \ | ||
47 | nop, \ | ||
48 | "\n1: " rdrand "\n\t" \ | ||
49 | "jc 2f\n\t" \ | ||
50 | "decl %0\n\t" \ | ||
51 | "jnz 1b\n\t" \ | ||
52 | "2:", \ | ||
53 | X86_FEATURE_RDRAND, \ | ||
54 | ASM_OUTPUT2("=r" (ok), "=a" (*v)), \ | ||
55 | "0" (RDRAND_RETRY_LOOPS)); \ | ||
56 | return ok; \ | ||
57 | } | ||
58 | |||
59 | #ifdef CONFIG_X86_64 | ||
60 | |||
61 | GET_RANDOM(arch_get_random_long, unsigned long, RDRAND_LONG, ASM_NOP5); | ||
62 | GET_RANDOM(arch_get_random_int, unsigned int, RDRAND_INT, ASM_NOP4); | ||
63 | |||
64 | #else | ||
65 | |||
66 | GET_RANDOM(arch_get_random_long, unsigned long, RDRAND_LONG, ASM_NOP3); | ||
67 | GET_RANDOM(arch_get_random_int, unsigned int, RDRAND_INT, ASM_NOP3); | ||
68 | |||
69 | #endif /* CONFIG_X86_64 */ | ||
70 | |||
71 | #endif /* CONFIG_ARCH_RANDOM */ | ||
72 | |||
73 | extern void x86_init_rdrand(struct cpuinfo_x86 *c); | ||
74 | |||
75 | #endif /* ASM_X86_ARCHRANDOM_H */ | ||
diff --git a/arch/x86/kernel/cpu/Makefile b/arch/x86/kernel/cpu/Makefile index fe6eb197f848..25f24dccdcfa 100644 --- a/arch/x86/kernel/cpu/Makefile +++ b/arch/x86/kernel/cpu/Makefile | |||
@@ -15,6 +15,7 @@ CFLAGS_common.o := $(nostackp) | |||
15 | obj-y := intel_cacheinfo.o scattered.o topology.o | 15 | obj-y := intel_cacheinfo.o scattered.o topology.o |
16 | obj-y += proc.o capflags.o powerflags.o common.o | 16 | obj-y += proc.o capflags.o powerflags.o common.o |
17 | obj-y += vmware.o hypervisor.o sched.o mshyperv.o | 17 | obj-y += vmware.o hypervisor.o sched.o mshyperv.o |
18 | obj-y += rdrand.o | ||
18 | 19 | ||
19 | obj-$(CONFIG_X86_32) += bugs.o | 20 | obj-$(CONFIG_X86_32) += bugs.o |
20 | obj-$(CONFIG_X86_64) += bugs_64.o | 21 | obj-$(CONFIG_X86_64) += bugs_64.o |
diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c index ec63df54d138..aa003b13a831 100644 --- a/arch/x86/kernel/cpu/common.c +++ b/arch/x86/kernel/cpu/common.c | |||
@@ -15,6 +15,7 @@ | |||
15 | #include <asm/stackprotector.h> | 15 | #include <asm/stackprotector.h> |
16 | #include <asm/perf_event.h> | 16 | #include <asm/perf_event.h> |
17 | #include <asm/mmu_context.h> | 17 | #include <asm/mmu_context.h> |
18 | #include <asm/archrandom.h> | ||
18 | #include <asm/hypervisor.h> | 19 | #include <asm/hypervisor.h> |
19 | #include <asm/processor.h> | 20 | #include <asm/processor.h> |
20 | #include <asm/sections.h> | 21 | #include <asm/sections.h> |
@@ -860,6 +861,7 @@ static void __cpuinit identify_cpu(struct cpuinfo_x86 *c) | |||
860 | #endif | 861 | #endif |
861 | 862 | ||
862 | init_hypervisor(c); | 863 | init_hypervisor(c); |
864 | x86_init_rdrand(c); | ||
863 | 865 | ||
864 | /* | 866 | /* |
865 | * Clear/Set all flags overriden by options, need do it | 867 | * Clear/Set all flags overriden by options, need do it |
diff --git a/arch/x86/kernel/cpu/rdrand.c b/arch/x86/kernel/cpu/rdrand.c new file mode 100644 index 000000000000..feca286c2bb4 --- /dev/null +++ b/arch/x86/kernel/cpu/rdrand.c | |||
@@ -0,0 +1,73 @@ | |||
1 | /* | ||
2 | * This file is part of the Linux kernel. | ||
3 | * | ||
4 | * Copyright (c) 2011, Intel Corporation | ||
5 | * Authors: Fenghua Yu <fenghua.yu@intel.com>, | ||
6 | * H. Peter Anvin <hpa@linux.intel.com> | ||
7 | * | ||
8 | * This program is free software; you can redistribute it and/or modify it | ||
9 | * under the terms and conditions of the GNU General Public License, | ||
10 | * version 2, as published by the Free Software Foundation. | ||
11 | * | ||
12 | * This program is distributed in the hope it will be useful, but WITHOUT | ||
13 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or | ||
14 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for | ||
15 | * more details. | ||
16 | * | ||
17 | * You should have received a copy of the GNU General Public License along with | ||
18 | * this program; if not, write to the Free Software Foundation, Inc., | ||
19 | * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA. | ||
20 | * | ||
21 | */ | ||
22 | |||
23 | #include <asm/processor.h> | ||
24 | #include <asm/archrandom.h> | ||
25 | #include <asm/sections.h> | ||
26 | |||
27 | static int __init x86_rdrand_setup(char *s) | ||
28 | { | ||
29 | setup_clear_cpu_cap(X86_FEATURE_RDRAND); | ||
30 | return 1; | ||
31 | } | ||
32 | __setup("nordrand", x86_rdrand_setup); | ||
33 | |||
34 | /* We can't use arch_get_random_long() here since alternatives haven't run */ | ||
35 | static inline int rdrand_long(unsigned long *v) | ||
36 | { | ||
37 | int ok; | ||
38 | asm volatile("1: " RDRAND_LONG "\n\t" | ||
39 | "jc 2f\n\t" | ||
40 | "decl %0\n\t" | ||
41 | "jnz 1b\n\t" | ||
42 | "2:" | ||
43 | : "=r" (ok), "=a" (*v) | ||
44 | : "0" (RDRAND_RETRY_LOOPS)); | ||
45 | return ok; | ||
46 | } | ||
47 | |||
48 | /* | ||
49 | * Force a reseed cycle; we are architecturally guaranteed a reseed | ||
50 | * after no more than 512 128-bit chunks of random data. This also | ||
51 | * acts as a test of the CPU capability. | ||
52 | */ | ||
53 | #define RESEED_LOOP ((512*128)/sizeof(unsigned long)) | ||
54 | |||
55 | void __cpuinit x86_init_rdrand(struct cpuinfo_x86 *c) | ||
56 | { | ||
57 | #ifdef CONFIG_ARCH_RANDOM | ||
58 | unsigned long tmp; | ||
59 | int i, count, ok; | ||
60 | |||
61 | if (!cpu_has(c, X86_FEATURE_RDRAND)) | ||
62 | return; /* Nothing to do */ | ||
63 | |||
64 | for (count = i = 0; i < RESEED_LOOP; i++) { | ||
65 | ok = rdrand_long(&tmp); | ||
66 | if (ok) | ||
67 | count++; | ||
68 | } | ||
69 | |||
70 | if (count != RESEED_LOOP) | ||
71 | clear_cpu_cap(c, X86_FEATURE_RDRAND); | ||
72 | #endif | ||
73 | } | ||