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Diffstat (limited to 'arch/x86/include/asm/segment.h')
-rw-r--r--arch/x86/include/asm/segment.h88
1 files changed, 32 insertions, 56 deletions
diff --git a/arch/x86/include/asm/segment.h b/arch/x86/include/asm/segment.h
index ac3892920419..f59ae7186940 100644
--- a/arch/x86/include/asm/segment.h
+++ b/arch/x86/include/asm/segment.h
@@ -4,6 +4,7 @@
#include <linux/const.h>
#include <asm/alternative.h>
+#include <asm/ibt.h>
/*
* Constructor for a conventional segment GDT (or LDT) entry.
@@ -31,6 +32,18 @@
*/
#define SEGMENT_RPL_MASK 0x3
+/*
+ * When running on Xen PV, the actual privilege level of the kernel is 1,
+ * not 0. Testing the Requested Privilege Level in a segment selector to
+ * determine whether the context is user mode or kernel mode with
+ * SEGMENT_RPL_MASK is wrong because the PV kernel's privilege level
+ * matches the 0x3 mask.
+ *
+ * Testing with USER_SEGMENT_RPL_MASK is valid for both native and Xen PV
+ * kernels because privilege level 2 is never used.
+ */
+#define USER_SEGMENT_RPL_MASK 0x2
+
/* User mode is privilege level 3: */
#define USER_RPL 0x3
@@ -43,7 +56,7 @@
#define GDT_ENTRY_INVALID_SEG 0
-#ifdef CONFIG_X86_32
+#if defined(CONFIG_X86_32) && !defined(BUILD_VDSO32_64)
/*
* The layout of the per-CPU GDT under Linux:
*
@@ -83,7 +96,7 @@
*
* 26 - ESPFIX small SS
* 27 - per-cpu [ offset to per-cpu data area ]
- * 28 - stack_canary-20 [ for stack protector ] <=== cacheline #8
+ * 28 - VDSO getcpu
* 29 - unused
* 30 - unused
* 31 - TSS for double fault handler
@@ -106,7 +119,7 @@
#define GDT_ENTRY_ESPFIX_SS 26
#define GDT_ENTRY_PERCPU 27
-#define GDT_ENTRY_STACK_CANARY 28
+#define GDT_ENTRY_CPUNODE 28
#define GDT_ENTRY_DOUBLEFAULT_TSS 31
@@ -123,6 +136,7 @@
#define __KERNEL_DS (GDT_ENTRY_KERNEL_DS*8)
#define __USER_DS (GDT_ENTRY_DEFAULT_USER_DS*8 + 3)
#define __USER_CS (GDT_ENTRY_DEFAULT_USER_CS*8 + 3)
+#define __USER32_CS __USER_CS
#define __ESPFIX_SS (GDT_ENTRY_ESPFIX_SS*8)
/* segment for calling fn: */
@@ -146,11 +160,7 @@
# define __KERNEL_PERCPU 0
#endif
-#ifdef CONFIG_STACKPROTECTOR
-# define __KERNEL_STACK_CANARY (GDT_ENTRY_STACK_CANARY*8)
-#else
-# define __KERNEL_STACK_CANARY 0
-#endif
+#define __CPUNODE_SEG (GDT_ENTRY_CPUNODE*8 + 3)
#else /* 64-bit: */
@@ -204,33 +214,26 @@
#define __KERNEL_DS (GDT_ENTRY_KERNEL_DS*8)
#define __USER32_CS (GDT_ENTRY_DEFAULT_USER32_CS*8 + 3)
#define __USER_DS (GDT_ENTRY_DEFAULT_USER_DS*8 + 3)
-#define __USER32_DS __USER_DS
#define __USER_CS (GDT_ENTRY_DEFAULT_USER_CS*8 + 3)
#define __CPUNODE_SEG (GDT_ENTRY_CPUNODE*8 + 3)
#endif
-#ifndef CONFIG_PARAVIRT_XXL
-# define get_kernel_rpl() 0
-#endif
-
#define IDT_ENTRIES 256
#define NUM_EXCEPTION_VECTORS 32
/* Bitmask of exception vectors which push an error code on the stack: */
-#define EXCEPTION_ERRCODE_MASK 0x00027d00
+#define EXCEPTION_ERRCODE_MASK 0x20027d00
#define GDT_SIZE (GDT_ENTRIES*8)
#define GDT_ENTRY_TLS_ENTRIES 3
#define TLS_SIZE (GDT_ENTRY_TLS_ENTRIES* 8)
-#ifdef CONFIG_X86_64
-
/* Bit size and mask of CPU number stored in the per CPU data (and TSC_AUX) */
#define VDSO_CPUNODE_BITS 12
#define VDSO_CPUNODE_MASK 0xfff
-#ifndef __ASSEMBLY__
+#ifndef __ASSEMBLER__
/* Helper functions to store/load CPU and node numbers */
@@ -241,7 +244,7 @@ static inline unsigned long vdso_encode_cpunode(int cpu, unsigned long node)
static inline void vdso_read_cpunode(unsigned *cpu, unsigned *node)
{
- unsigned int p;
+ unsigned long p;
/*
* Load CPU and node number from the GDT. LSL is faster than RDTSCP
@@ -251,10 +254,10 @@ static inline void vdso_read_cpunode(unsigned *cpu, unsigned *node)
*
* If RDPID is available, use it.
*/
- alternative_io ("lsl %[seg],%[p]",
- ".byte 0xf3,0x0f,0xc7,0xf8", /* RDPID %eax/rax */
+ alternative_io ("lsl %[seg],%k[p]",
+ "rdpid %[p]",
X86_FEATURE_RDPID,
- [p] "=a" (p), [seg] "r" (__CPUNODE_SEG));
+ [p] "=r" (p), [seg] "r" (__CPUNODE_SEG));
if (cpu)
*cpu = (p & VDSO_CPUNODE_MASK);
@@ -262,8 +265,7 @@ static inline void vdso_read_cpunode(unsigned *cpu, unsigned *node)
*node = (p >> VDSO_CPUNODE_BITS);
}
-#endif /* !__ASSEMBLY__ */
-#endif /* CONFIG_X86_64 */
+#endif /* !__ASSEMBLER__ */
#ifdef __KERNEL__
@@ -274,7 +276,7 @@ static inline void vdso_read_cpunode(unsigned *cpu, unsigned *node)
* vector has no error code (two bytes), a 'push $vector_number' (two
* bytes), and a jump to the common entry code (up to five bytes).
*/
-#define EARLY_IDT_HANDLER_SIZE 9
+#define EARLY_IDT_HANDLER_SIZE (9 + ENDBR_INSN_SIZE)
/*
* xen_early_idt_handler_array is for Xen pv guests: for each entry in
@@ -282,14 +284,14 @@ static inline void vdso_read_cpunode(unsigned *cpu, unsigned *node)
* pop %rcx; pop %r11; jmp early_idt_handler_array[i]; summing up to
* max 8 bytes.
*/
-#define XEN_EARLY_IDT_HANDLER_SIZE 8
+#define XEN_EARLY_IDT_HANDLER_SIZE (8 + ENDBR_INSN_SIZE)
-#ifndef __ASSEMBLY__
+#ifndef __ASSEMBLER__
extern const char early_idt_handler_array[NUM_EXCEPTION_VECTORS][EARLY_IDT_HANDLER_SIZE];
extern void early_ignore_irq(void);
-#if defined(CONFIG_X86_64) && defined(CONFIG_XEN_PV)
+#ifdef CONFIG_XEN_PV
extern const char xen_early_idt_handler_array[NUM_EXCEPTION_VECTORS][XEN_EARLY_IDT_HANDLER_SIZE];
#endif
@@ -306,14 +308,7 @@ do { \
\
asm volatile(" \n" \
"1: movl %k0,%%" #seg " \n" \
- \
- ".section .fixup,\"ax\" \n" \
- "2: xorl %k0,%k0 \n" \
- " jmp 1b \n" \
- ".previous \n" \
- \
- _ASM_EXTABLE(1b, 2b) \
- \
+ _ASM_EXTABLE_TYPE_REG(1b, 1b, EX_TYPE_ZERO_REG, %k0)\
: "+r" (__val) : : "memory"); \
} while (0)
@@ -338,7 +333,7 @@ static inline void __loadsegment_fs(unsigned short value)
"1: movw %0, %%fs \n"
"2: \n"
- _ASM_EXTABLE_HANDLE(1b, 2b, ex_handler_clear_fs)
+ _ASM_EXTABLE_TYPE(1b, 2b, EX_TYPE_CLEAR_FS)
: : "rm" (value) : "memory");
}
@@ -355,26 +350,7 @@ static inline void __loadsegment_fs(unsigned short value)
#define savesegment(seg, value) \
asm("mov %%" #seg ",%0":"=r" (value) : : "memory")
-/*
- * x86-32 user GS accessors:
- */
-#ifdef CONFIG_X86_32
-# ifdef CONFIG_X86_32_LAZY_GS
-# define get_user_gs(regs) (u16)({ unsigned long v; savesegment(gs, v); v; })
-# define set_user_gs(regs, v) loadsegment(gs, (unsigned long)(v))
-# define task_user_gs(tsk) ((tsk)->thread.gs)
-# define lazy_save_gs(v) savesegment(gs, (v))
-# define lazy_load_gs(v) loadsegment(gs, (v))
-# else /* X86_32_LAZY_GS */
-# define get_user_gs(regs) (u16)((regs)->gs)
-# define set_user_gs(regs, v) do { (regs)->gs = (v); } while (0)
-# define task_user_gs(tsk) (task_pt_regs(tsk)->gs)
-# define lazy_save_gs(v) do { } while (0)
-# define lazy_load_gs(v) do { } while (0)
-# endif /* X86_32_LAZY_GS */
-#endif /* X86_32 */
-
-#endif /* !__ASSEMBLY__ */
+#endif /* !__ASSEMBLER__ */
#endif /* __KERNEL__ */
#endif /* _ASM_X86_SEGMENT_H */
generated by cgit (git 2.34.1) at 2025-12-22 09:53:32 +0000