Separating the functions for getting random long number from KASLR
to x86 library, then it can be used to generate random long for
EFI root key.
Cc: Kees Cook <keescook@xxxxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: "H. Peter Anvin" <hpa@xxxxxxxxx>
Cc: "Rafael J. Wysocki" <rafael.j.wysocki@xxxxxxxxx>
Cc: Pavel Machek <pavel@xxxxxx>
Cc: Chen Yu <yu.c.chen@xxxxxxxxx>
Cc: Oliver Neukum <oneukum@xxxxxxxx>
Cc: Ryan Chen <yu.chen.surf@xxxxxxxxx>
Cc: Ard Biesheuvel <ard.biesheuvel@xxxxxxxxxx>
Cc: David Howells <dhowells@xxxxxxxxxx>
Cc: Mimi Zohar <zohar@xxxxxxxxxxxxxxxxxx>
Signed-off-by: "Lee, Chun-Yi" <jlee@xxxxxxxx>
---
arch/x86/boot/compressed/kaslr.c | 21 -------------
arch/x86/boot/compressed/misc.c | 17 ++++++++++
arch/x86/boot/compressed/misc.h | 6 ++++
arch/x86/lib/kaslr.c | 61 ++---------------------------------
arch/x86/lib/random.c | 68 ++++++++++++++++++++++++++++++++++++++++
5 files changed, 93 insertions(+), 80 deletions(-)
create mode 100644 arch/x86/lib/random.c
diff --git a/arch/x86/boot/compressed/kaslr.c b/arch/x86/boot/compressed/kaslr.c
index b87a7582853d..0f40d2178ebc 100644
--- a/arch/x86/boot/compressed/kaslr.c
+++ b/arch/x86/boot/compressed/kaslr.c
@@ -33,13 +33,11 @@
#include "error.h"
#include "../string.h"
-#include <generated/compile.h>
#include <linux/module.h>
#include <linux/uts.h>
#include <linux/utsname.h>
#include <linux/ctype.h>
#include <linux/efi.h>
-#include <generated/utsrelease.h>
#include <asm/efi.h>
/* Macros used by the included decompressor code below. */
@@ -57,25 +55,6 @@ extern unsigned long get_cmd_line_ptr(void);
/* Used by PAGE_KERN* macros: */
pteval_t __default_kernel_pte_mask __read_mostly = ~0;
-/* Simplified build-specific string for starting entropy. */
-static const char build_str[] = UTS_RELEASE " (" LINUX_COMPILE_BY "@"
- LINUX_COMPILE_HOST ") (" LINUX_COMPILER ") " UTS_VERSION;
-
-static unsigned long rotate_xor(unsigned long hash, const void *area,
- size_t size)
-{
- size_t i;
- unsigned long *ptr = (unsigned long *)area;
-
- for (i = 0; i < size / sizeof(hash); i++) {
- /* Rotate by odd number of bits and XOR. */
- hash = (hash << ((sizeof(hash) * 8) - 7)) | (hash >> 7);
- hash ^= ptr[i];
- }
-
- return hash;
-}
-
/* Attempt to create a simple but unpredictable starting entropy. */
static unsigned long get_boot_seed(void)
{
diff --git a/arch/x86/boot/compressed/misc.c b/arch/x86/boot/compressed/misc.c
index 8dd1d5ccae58..eb0ab9cad4e4 100644
--- a/arch/x86/boot/compressed/misc.c
+++ b/arch/x86/boot/compressed/misc.c
@@ -426,3 +426,20 @@ void fortify_panic(const char *name)
{
error("detected buffer overflow");
}
+
+#if CONFIG_RANDOMIZE_BASE
+unsigned long rotate_xor(unsigned long hash, const void *area,
+ size_t size)
+{
+ size_t i;
+ unsigned long *ptr = (unsigned long *)area;
+
+ for (i = 0; i < size / sizeof(hash); i++) {
+ /* Rotate by odd number of bits and XOR. */
+ hash = (hash << ((sizeof(hash) * 8) - 7)) | (hash >> 7);
+ hash ^= ptr[i];
+ }
+
+ return hash;
+}
+#endif
diff --git a/arch/x86/boot/compressed/misc.h b/arch/x86/boot/compressed/misc.h
index a423bdb42686..957f327ad83c 100644
--- a/arch/x86/boot/compressed/misc.h
+++ b/arch/x86/boot/compressed/misc.h
@@ -70,6 +70,8 @@ int cmdline_find_option_bool(const char *option);
#if CONFIG_RANDOMIZE_BASE
+#include <generated/compile.h>
+#include <generated/utsrelease.h>
/* kaslr.c */
void choose_random_location(unsigned long input,
unsigned long input_size,
@@ -78,6 +80,10 @@ void choose_random_location(unsigned long input,
unsigned long *virt_addr);
/* cpuflags.c */
bool has_cpuflag(int flag);
+/* Simplified build-specific string for starting entropy. */
+static const char build_str[] = UTS_RELEASE " (" LINUX_COMPILE_BY "@"
+ LINUX_COMPILE_HOST ") (" LINUX_COMPILER ") " UTS_VERSION;
+unsigned long rotate_xor(unsigned long hash, const void *area, size_t size);
#else
static inline void choose_random_location(unsigned long input,
unsigned long input_size,
diff --git a/arch/x86/lib/kaslr.c b/arch/x86/lib/kaslr.c
index 79778ab200e4..29ed9bfde5a5 100644
--- a/arch/x86/lib/kaslr.c
+++ b/arch/x86/lib/kaslr.c
@@ -26,67 +26,10 @@
#define get_boot_seed() kaslr_offset()
#endif
-#define I8254_PORT_CONTROL 0x43
-#define I8254_PORT_COUNTER0 0x40
-#define I8254_CMD_READBACK 0xC0
-#define I8254_SELECT_COUNTER0 0x02
-#define I8254_STATUS_NOTREADY 0x40
-static inline u16 i8254(void)
-{
- u16 status, timer;
-
- do {
- outb(I8254_PORT_CONTROL,
- I8254_CMD_READBACK | I8254_SELECT_COUNTER0);
- status = inb(I8254_PORT_COUNTER0);
- timer = inb(I8254_PORT_COUNTER0);
- timer |= inb(I8254_PORT_COUNTER0) << 8;
- } while (status & I8254_STATUS_NOTREADY);
-
- return timer;
-}
+#include "random.c"
unsigned long kaslr_get_random_long(const char *purpose)
{
-#ifdef CONFIG_X86_64
- const unsigned long mix_const = 0x5d6008cbf3848dd3UL;
-#else
- const unsigned long mix_const = 0x3f39e593UL;
-#endif
- unsigned long raw, random = get_boot_seed();
- bool use_i8254 = true;
-
- debug_putstr(purpose);
debug_putstr(" KASLR using");
-
- if (has_cpuflag(X86_FEATURE_RDRAND)) {
- debug_putstr(" RDRAND");
- if (rdrand_long(&raw)) {
- random ^= raw;
- use_i8254 = false;
- }
- }
-
- if (has_cpuflag(X86_FEATURE_TSC)) {
- debug_putstr(" RDTSC");
- raw = rdtsc();
-
- random ^= raw;
- use_i8254 = false;
- }
-
- if (use_i8254) {
- debug_putstr(" i8254");
- random ^= i8254();
- }
-
- /* Circular multiply for better bit diffusion */
- asm(_ASM_MUL "%3"
- : "=a" (random), "=d" (raw)
- : "a" (random), "rm" (mix_const));
- random += raw;
-
- debug_putstr("...\n");
-
- return random;
+ return get_random_long(purpose);
}
diff --git a/arch/x86/lib/random.c b/arch/x86/lib/random.c
new file mode 100644
index 000000000000..f2fe6a784c98
--- /dev/null
+++ b/arch/x86/lib/random.c
@@ -0,0 +1,68 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include <asm/io.h>
+#include <asm/archrandom.h>
+
+#define I8254_PORT_CONTROL 0x43
+#define I8254_PORT_COUNTER0 0x40
+#define I8254_CMD_READBACK 0xC0
+#define I8254_SELECT_COUNTER0 0x02
+#define I8254_STATUS_NOTREADY 0x40
+static inline u16 i8254(void)
+{
+ u16 status, timer;
+
+ do {
+ outb(I8254_PORT_CONTROL,
+ I8254_CMD_READBACK | I8254_SELECT_COUNTER0);
+ status = inb(I8254_PORT_COUNTER0);
+ timer = inb(I8254_PORT_COUNTER0);
+ timer |= inb(I8254_PORT_COUNTER0) << 8;
+ } while (status & I8254_STATUS_NOTREADY);
+
+ return timer;
+}
+
+static unsigned long get_random_long(const char *purpose)
+{
+#ifdef CONFIG_X86_64
+ const unsigned long mix_const = 0x5d6008cbf3848dd3UL;
+#else
+ const unsigned long mix_const = 0x3f39e593UL;
+#endif
+ unsigned long raw, random = get_boot_seed();
+ bool use_i8254 = true;
+
+ debug_putstr(purpose);
+
+ if (has_cpuflag(X86_FEATURE_RDRAND)) {
+ debug_putstr(" RDRAND");
+ if (rdrand_long(&raw)) {
+ random ^= raw;
+ use_i8254 = false;
+ }
+ }
+
+ if (has_cpuflag(X86_FEATURE_TSC)) {
+ debug_putstr(" RDTSC");
+ raw = rdtsc();
+
+ random ^= raw;
+ use_i8254 = false;
+ }
+
+ if (use_i8254) {
+ debug_putstr(" i8254");
+ random ^= i8254();
+ }
+
+ /* Circular multiply for better bit diffusion */
+ asm(_ASM_MUL "%3"
+ : "=a" (random), "=d" (raw)
+ : "a" (random), "rm" (mix_const));
+ random += raw;
+
+ debug_putstr("...\n");
+
+ return random;
+}
--
2.13.6
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