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-rw-r--r--arch/x86/include/asm/uaccess.h55
-rw-r--r--arch/x86/kernel/i386_ksyms_32.c1
-rw-r--r--arch/x86/kernel/kvm.c4
-rw-r--r--arch/x86/kernel/setup.c13
-rw-r--r--arch/x86/lib/getuser.S43
5 files changed, 68 insertions, 48 deletions
diff --git a/arch/x86/include/asm/uaccess.h b/arch/x86/include/asm/uaccess.h
index 1709801d18ec..5ee26875baea 100644
--- a/arch/x86/include/asm/uaccess.h
+++ b/arch/x86/include/asm/uaccess.h
@@ -125,13 +125,12 @@ extern int __get_user_4(void);
extern int __get_user_8(void);
extern int __get_user_bad(void);
-#define __get_user_x(size, ret, x, ptr) \
- asm volatile("call __get_user_" #size \
- : "=a" (ret), "=d" (x) \
- : "0" (ptr)) \
-
-/* Careful: we have to cast the result to the type of the pointer
- * for sign reasons */
+/*
+ * This is a type: either unsigned long, if the argument fits into
+ * that type, or otherwise unsigned long long.
+ */
+#define __inttype(x) \
+__typeof__(__builtin_choose_expr(sizeof(x) > sizeof(0UL), 0ULL, 0UL))
/**
* get_user: - Get a simple variable from user space.
@@ -150,38 +149,26 @@ extern int __get_user_bad(void);
* Returns zero on success, or -EFAULT on error.
* On error, the variable @x is set to zero.
*/
-#ifdef CONFIG_X86_32
-#define __get_user_8(__ret_gu, __val_gu, ptr) \
- __get_user_x(X, __ret_gu, __val_gu, ptr)
-#else
-#define __get_user_8(__ret_gu, __val_gu, ptr) \
- __get_user_x(8, __ret_gu, __val_gu, ptr)
-#endif
-
+/*
+ * Careful: we have to cast the result to the type of the pointer
+ * for sign reasons.
+ *
+ * The use of %edx as the register specifier is a bit of a
+ * simplification, as gcc only cares about it as the starting point
+ * and not size: for a 64-bit value it will use %ecx:%edx on 32 bits
+ * (%ecx being the next register in gcc's x86 register sequence), and
+ * %rdx on 64 bits.
+ */
#define get_user(x, ptr) \
({ \
int __ret_gu; \
- unsigned long __val_gu; \
+ register __inttype(*(ptr)) __val_gu asm("%edx"); \
__chk_user_ptr(ptr); \
might_fault(); \
- switch (sizeof(*(ptr))) { \
- case 1: \
- __get_user_x(1, __ret_gu, __val_gu, ptr); \
- break; \
- case 2: \
- __get_user_x(2, __ret_gu, __val_gu, ptr); \
- break; \
- case 4: \
- __get_user_x(4, __ret_gu, __val_gu, ptr); \
- break; \
- case 8: \
- __get_user_8(__ret_gu, __val_gu, ptr); \
- break; \
- default: \
- __get_user_x(X, __ret_gu, __val_gu, ptr); \
- break; \
- } \
- (x) = (__typeof__(*(ptr)))__val_gu; \
+ asm volatile("call __get_user_%P3" \
+ : "=a" (__ret_gu), "=r" (__val_gu) \
+ : "0" (ptr), "i" (sizeof(*(ptr)))); \
+ (x) = (__typeof__(*(ptr))) __val_gu; \
__ret_gu; \
})
diff --git a/arch/x86/kernel/i386_ksyms_32.c b/arch/x86/kernel/i386_ksyms_32.c
index 9c3bd4a2050e..0fa69127209a 100644
--- a/arch/x86/kernel/i386_ksyms_32.c
+++ b/arch/x86/kernel/i386_ksyms_32.c
@@ -26,6 +26,7 @@ EXPORT_SYMBOL(csum_partial_copy_generic);
EXPORT_SYMBOL(__get_user_1);
EXPORT_SYMBOL(__get_user_2);
EXPORT_SYMBOL(__get_user_4);
+EXPORT_SYMBOL(__get_user_8);
EXPORT_SYMBOL(__put_user_1);
EXPORT_SYMBOL(__put_user_2);
diff --git a/arch/x86/kernel/kvm.c b/arch/x86/kernel/kvm.c
index aa7e58b82b39..9cec20253093 100644
--- a/arch/x86/kernel/kvm.c
+++ b/arch/x86/kernel/kvm.c
@@ -298,8 +298,8 @@ static void kvm_register_steal_time(void)
memset(st, 0, sizeof(*st));
wrmsrl(MSR_KVM_STEAL_TIME, (slow_virt_to_phys(st) | KVM_MSR_ENABLED));
- printk(KERN_INFO "kvm-stealtime: cpu %d, msr %lx\n",
- cpu, slow_virt_to_phys(st));
+ pr_info("kvm-stealtime: cpu %d, msr %llx\n",
+ cpu, (unsigned long long) slow_virt_to_phys(st));
}
static DEFINE_PER_CPU(unsigned long, kvm_apic_eoi) = KVM_PV_EOI_DISABLED;
diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c
index be6e435cfc05..878cf1d326e5 100644
--- a/arch/x86/kernel/setup.c
+++ b/arch/x86/kernel/setup.c
@@ -644,8 +644,6 @@ static __init void reserve_ibft_region(void)
memblock_reserve(addr, size);
}
-static unsigned reserve_low = CONFIG_X86_RESERVE_LOW << 10;
-
static bool __init snb_gfx_workaround_needed(void)
{
#ifdef CONFIG_PCI
@@ -734,8 +732,7 @@ static void __init trim_bios_range(void)
* since some BIOSes are known to corrupt low memory. See the
* Kconfig help text for X86_RESERVE_LOW.
*/
- e820_update_range(0, ALIGN(reserve_low, PAGE_SIZE),
- E820_RAM, E820_RESERVED);
+ e820_update_range(0, PAGE_SIZE, E820_RAM, E820_RESERVED);
/*
* special case: Some BIOSen report the PC BIOS
@@ -768,6 +765,8 @@ static void __init e820_add_kernel_range(void)
e820_add_region(start, size, E820_RAM);
}
+static unsigned reserve_low = CONFIG_X86_RESERVE_LOW << 10;
+
static int __init parse_reservelow(char *p)
{
unsigned long long size;
@@ -790,6 +789,11 @@ static int __init parse_reservelow(char *p)
early_param("reservelow", parse_reservelow);
+static void __init trim_low_memory_range(void)
+{
+ memblock_reserve(0, ALIGN(reserve_low, PAGE_SIZE));
+}
+
/*
* Determine if we were loaded by an EFI loader. If so, then we have also been
* passed the efi memmap, systab, etc., so we should use these data structures
@@ -1060,6 +1064,7 @@ void __init setup_arch(char **cmdline_p)
reserve_real_mode();
trim_platform_memory_ranges();
+ trim_low_memory_range();
init_mem_mapping();
diff --git a/arch/x86/lib/getuser.S b/arch/x86/lib/getuser.S
index 156b9c804670..a4512359656a 100644
--- a/arch/x86/lib/getuser.S
+++ b/arch/x86/lib/getuser.S
@@ -15,11 +15,10 @@
* __get_user_X
*
* Inputs: %[r|e]ax contains the address.
- * The register is modified, but all changes are undone
- * before returning because the C code doesn't know about it.
*
* Outputs: %[r|e]ax is error code (0 or -EFAULT)
* %[r|e]dx contains zero-extended value
+ * %ecx contains the high half for 32-bit __get_user_8
*
*
* These functions should not modify any other registers,
@@ -42,7 +41,7 @@ ENTRY(__get_user_1)
cmp TI_addr_limit(%_ASM_DX),%_ASM_AX
jae bad_get_user
ASM_STAC
-1: movzb (%_ASM_AX),%edx
+1: movzbl (%_ASM_AX),%edx
xor %eax,%eax
ASM_CLAC
ret
@@ -72,29 +71,42 @@ ENTRY(__get_user_4)
cmp TI_addr_limit(%_ASM_DX),%_ASM_AX
jae bad_get_user
ASM_STAC
-3: mov -3(%_ASM_AX),%edx
+3: movl -3(%_ASM_AX),%edx
xor %eax,%eax
ASM_CLAC
ret
CFI_ENDPROC
ENDPROC(__get_user_4)
-#ifdef CONFIG_X86_64
ENTRY(__get_user_8)
CFI_STARTPROC
+#ifdef CONFIG_X86_64
add $7,%_ASM_AX
jc bad_get_user
GET_THREAD_INFO(%_ASM_DX)
cmp TI_addr_limit(%_ASM_DX),%_ASM_AX
- jae bad_get_user
+ jae bad_get_user
ASM_STAC
-4: movq -7(%_ASM_AX),%_ASM_DX
+4: movq -7(%_ASM_AX),%rdx
xor %eax,%eax
ASM_CLAC
ret
+#else
+ add $7,%_ASM_AX
+ jc bad_get_user_8
+ GET_THREAD_INFO(%_ASM_DX)
+ cmp TI_addr_limit(%_ASM_DX),%_ASM_AX
+ jae bad_get_user_8
+ ASM_STAC
+4: movl -7(%_ASM_AX),%edx
+5: movl -3(%_ASM_AX),%ecx
+ xor %eax,%eax
+ ASM_CLAC
+ ret
+#endif
CFI_ENDPROC
ENDPROC(__get_user_8)
-#endif
+
bad_get_user:
CFI_STARTPROC
@@ -105,9 +117,24 @@ bad_get_user:
CFI_ENDPROC
END(bad_get_user)
+#ifdef CONFIG_X86_32
+bad_get_user_8:
+ CFI_STARTPROC
+ xor %edx,%edx
+ xor %ecx,%ecx
+ mov $(-EFAULT),%_ASM_AX
+ ASM_CLAC
+ ret
+ CFI_ENDPROC
+END(bad_get_user_8)
+#endif
+
_ASM_EXTABLE(1b,bad_get_user)
_ASM_EXTABLE(2b,bad_get_user)
_ASM_EXTABLE(3b,bad_get_user)
#ifdef CONFIG_X86_64
_ASM_EXTABLE(4b,bad_get_user)
+#else
+ _ASM_EXTABLE(4b,bad_get_user_8)
+ _ASM_EXTABLE(5b,bad_get_user_8)
#endif
generated by cgit v1.2.3 (git 2.39.0) at 2025-02-19 10:08:43 +0300