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Commit 106b88d7 authored by Linus Torvalds's avatar Linus Torvalds
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Merge tag 'x86-asm-2024-01-08' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 

Pull x86 asm updates from Ingo Molnar:
 "Replace magic numbers in GDT descriptor definitions & handling:

   - Introduce symbolic names via macros for descriptor
     types/fields/flags, and then use these symbolic names.

   - Clean up definitions a bit, such as GDT_ENTRY_INIT()

   - Fix/clean up details that became visibly inconsistent after the
     symbol-based code was introduced:

      - Unify accessed flag handling

      - Set the D/B size flag consistently & according to the HW
        specification"

* tag 'x86-asm-2024-01-08' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/asm: Add DB flag to 32-bit percpu GDT entry
  x86/asm: Always set A (accessed) flag in GDT descriptors
  x86/asm: Replace magic numbers in GDT descriptors, script-generated change
  x86/asm: Replace magic numbers in GDT descriptors, preparations
  x86/asm: Provide new infrastructure for GDT descriptors
parents 33034c4f bc90aefa
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Showing with 105 additions and 58 deletions
arch/x86/boot/pm.c
View file @ 106b88d7
......@@ -11,6 +11,7 @@
*/
#include "boot.h"
#include <asm/desc_defs.h>
#include <asm/segment.h>
/*
......@@ -67,13 +68,13 @@ static void setup_gdt(void)
being 8-byte unaligned. Intel recommends 16 byte alignment. */
static const u64 boot_gdt[] __attribute__((aligned(16))) = {
/* CS: code, read/execute, 4 GB, base 0 */
[GDT_ENTRY_BOOT_CS] = GDT_ENTRY(0xc09b, 0, 0xfffff),
[GDT_ENTRY_BOOT_CS] = GDT_ENTRY(DESC_CODE32, 0, 0xfffff),
/* DS: data, read/write, 4 GB, base 0 */
[GDT_ENTRY_BOOT_DS] = GDT_ENTRY(0xc093, 0, 0xfffff),
[GDT_ENTRY_BOOT_DS] = GDT_ENTRY(DESC_DATA32, 0, 0xfffff),
/* TSS: 32-bit tss, 104 bytes, base 4096 */
/* We only have a TSS here to keep Intel VT happy;
we don't actually use it for anything. */
[GDT_ENTRY_BOOT_TSS] = GDT_ENTRY(0x0089, 4096, 103),
[GDT_ENTRY_BOOT_TSS] = GDT_ENTRY(DESC_TSS32, 4096, 103),
};
/* Xen HVM incorrectly stores a pointer to the gdt_ptr, instead
of the gdt_ptr contents. Thus, make it static so it will
......
arch/x86/include/asm/desc_defs.h
View file @ 106b88d7
......@@ -8,6 +8,56 @@
* archs.
*/
/*
* Low-level interface mapping flags/field names to bits
*/
/* Flags for _DESC_S (non-system) descriptors */
#define _DESC_ACCESSED 0x0001
#define _DESC_DATA_WRITABLE 0x0002
#define _DESC_CODE_READABLE 0x0002
#define _DESC_DATA_EXPAND_DOWN 0x0004
#define _DESC_CODE_CONFORMING 0x0004
#define _DESC_CODE_EXECUTABLE 0x0008
/* Common flags */
#define _DESC_S 0x0010
#define _DESC_DPL(dpl) ((dpl) << 5)
#define _DESC_PRESENT 0x0080
#define _DESC_LONG_CODE 0x2000
#define _DESC_DB 0x4000
#define _DESC_GRANULARITY_4K 0x8000
/* System descriptors have a numeric "type" field instead of flags */
#define _DESC_SYSTEM(code) (code)
/*
* High-level interface mapping intended usage to low-level combinations
* of flags
*/
#define _DESC_DATA (_DESC_S | _DESC_PRESENT | _DESC_ACCESSED | \
_DESC_DATA_WRITABLE)
#define _DESC_CODE (_DESC_S | _DESC_PRESENT | _DESC_ACCESSED | \
_DESC_CODE_READABLE | _DESC_CODE_EXECUTABLE)
#define DESC_DATA16 (_DESC_DATA)
#define DESC_CODE16 (_DESC_CODE)
#define DESC_DATA32 (_DESC_DATA | _DESC_GRANULARITY_4K | _DESC_DB)
#define DESC_DATA32_BIOS (_DESC_DATA | _DESC_DB)
#define DESC_CODE32 (_DESC_CODE | _DESC_GRANULARITY_4K | _DESC_DB)
#define DESC_CODE32_BIOS (_DESC_CODE | _DESC_DB)
#define DESC_TSS32 (_DESC_SYSTEM(9) | _DESC_PRESENT)
#define DESC_DATA64 (_DESC_DATA | _DESC_GRANULARITY_4K | _DESC_DB)
#define DESC_CODE64 (_DESC_CODE | _DESC_GRANULARITY_4K | _DESC_LONG_CODE)
#define DESC_USER (_DESC_DPL(3))
#ifndef __ASSEMBLY__
#include <linux/types.h>
......@@ -22,19 +72,19 @@ struct desc_struct {
#define GDT_ENTRY_INIT(flags, base, limit) \
{ \
.limit0 = (u16) (limit), \
.limit1 = ((limit) >> 16) & 0x0F, \
.base0 = (u16) (base), \
.base1 = ((base) >> 16) & 0xFF, \
.base2 = ((base) >> 24) & 0xFF, \
.type = (flags & 0x0f), \
.s = (flags >> 4) & 0x01, \
.dpl = (flags >> 5) & 0x03, \
.p = (flags >> 7) & 0x01, \
.avl = (flags >> 12) & 0x01, \
.l = (flags >> 13) & 0x01, \
.d = (flags >> 14) & 0x01, \
.g = (flags >> 15) & 0x01, \
.limit0 = ((limit) >> 0) & 0xFFFF, \
.limit1 = ((limit) >> 16) & 0x000F, \
.base0 = ((base) >> 0) & 0xFFFF, \
.base1 = ((base) >> 16) & 0x00FF, \
.base2 = ((base) >> 24) & 0x00FF, \
.type = ((flags) >> 0) & 0x000F, \
.s = ((flags) >> 4) & 0x0001, \
.dpl = ((flags) >> 5) & 0x0003, \
.p = ((flags) >> 7) & 0x0001, \
.avl = ((flags) >> 12) & 0x0001, \
.l = ((flags) >> 13) & 0x0001, \
.d = ((flags) >> 14) & 0x0001, \
.g = ((flags) >> 15) & 0x0001, \
}
enum {
......@@ -94,6 +144,7 @@ struct gate_struct {
typedef struct gate_struct gate_desc;
#ifndef _SETUP
static inline unsigned long gate_offset(const gate_desc *g)
{
#ifdef CONFIG_X86_64
......@@ -108,6 +159,7 @@ static inline unsigned long gate_segment(const gate_desc *g)
{
return g->segment;
}
#endif
struct desc_ptr {
unsigned short size;
......
arch/x86/kernel/apm_32.c
View file @ 106b88d7
......@@ -420,7 +420,7 @@ static DEFINE_MUTEX(apm_mutex);
* This is for buggy BIOS's that refer to (real mode) segment 0x40
* even though they are called in protected mode.
*/
static struct desc_struct bad_bios_desc = GDT_ENTRY_INIT(0x4092,
static struct desc_struct bad_bios_desc = GDT_ENTRY_INIT(DESC_DATA32_BIOS,
(unsigned long)__va(0x400UL), PAGE_SIZE - 0x400 - 1);
static const char driver_version[] = "1.16ac"; /* no spaces */
......
arch/x86/kernel/cpu/common.c
View file @ 106b88d7
......@@ -188,45 +188,37 @@ DEFINE_PER_CPU_PAGE_ALIGNED(struct gdt_page, gdt_page) = { .gdt = {
* TLS descriptors are currently at a different place compared to i386.
* Hopefully nobody expects them at a fixed place (Wine?)
*/
[GDT_ENTRY_KERNEL32_CS] = GDT_ENTRY_INIT(0xc09b, 0, 0xfffff),
[GDT_ENTRY_KERNEL_CS] = GDT_ENTRY_INIT(0xa09b, 0, 0xfffff),
[GDT_ENTRY_KERNEL_DS] = GDT_ENTRY_INIT(0xc093, 0, 0xfffff),
[GDT_ENTRY_DEFAULT_USER32_CS] = GDT_ENTRY_INIT(0xc0fb, 0, 0xfffff),
[GDT_ENTRY_DEFAULT_USER_DS] = GDT_ENTRY_INIT(0xc0f3, 0, 0xfffff),
[GDT_ENTRY_DEFAULT_USER_CS] = GDT_ENTRY_INIT(0xa0fb, 0, 0xfffff),
[GDT_ENTRY_KERNEL32_CS] = GDT_ENTRY_INIT(DESC_CODE32, 0, 0xfffff),
[GDT_ENTRY_KERNEL_CS] = GDT_ENTRY_INIT(DESC_CODE64, 0, 0xfffff),
[GDT_ENTRY_KERNEL_DS] = GDT_ENTRY_INIT(DESC_DATA64, 0, 0xfffff),
[GDT_ENTRY_DEFAULT_USER32_CS] = GDT_ENTRY_INIT(DESC_CODE32 | DESC_USER, 0, 0xfffff),
[GDT_ENTRY_DEFAULT_USER_DS] = GDT_ENTRY_INIT(DESC_DATA64 | DESC_USER, 0, 0xfffff),
[GDT_ENTRY_DEFAULT_USER_CS] = GDT_ENTRY_INIT(DESC_CODE64 | DESC_USER, 0, 0xfffff),
#else
[GDT_ENTRY_KERNEL_CS] = GDT_ENTRY_INIT(0xc09a, 0, 0xfffff),
[GDT_ENTRY_KERNEL_DS] = GDT_ENTRY_INIT(0xc092, 0, 0xfffff),
[GDT_ENTRY_DEFAULT_USER_CS] = GDT_ENTRY_INIT(0xc0fa, 0, 0xfffff),
[GDT_ENTRY_DEFAULT_USER_DS] = GDT_ENTRY_INIT(0xc0f2, 0, 0xfffff),
[GDT_ENTRY_KERNEL_CS] = GDT_ENTRY_INIT(DESC_CODE32, 0, 0xfffff),
[GDT_ENTRY_KERNEL_DS] = GDT_ENTRY_INIT(DESC_DATA32, 0, 0xfffff),
[GDT_ENTRY_DEFAULT_USER_CS] = GDT_ENTRY_INIT(DESC_CODE32 | DESC_USER, 0, 0xfffff),
[GDT_ENTRY_DEFAULT_USER_DS] = GDT_ENTRY_INIT(DESC_DATA32 | DESC_USER, 0, 0xfffff),
/*
* Segments used for calling PnP BIOS have byte granularity.
* They code segments and data segments have fixed 64k limits,
* the transfer segment sizes are set at run time.
*/
/* 32-bit code */
[GDT_ENTRY_PNPBIOS_CS32] = GDT_ENTRY_INIT(0x409a, 0, 0xffff),
/* 16-bit code */
[GDT_ENTRY_PNPBIOS_CS16] = GDT_ENTRY_INIT(0x009a, 0, 0xffff),
/* 16-bit data */
[GDT_ENTRY_PNPBIOS_DS] = GDT_ENTRY_INIT(0x0092, 0, 0xffff),
/* 16-bit data */
[GDT_ENTRY_PNPBIOS_TS1] = GDT_ENTRY_INIT(0x0092, 0, 0),
/* 16-bit data */
[GDT_ENTRY_PNPBIOS_TS2] = GDT_ENTRY_INIT(0x0092, 0, 0),
[GDT_ENTRY_PNPBIOS_CS32] = GDT_ENTRY_INIT(DESC_CODE32_BIOS, 0, 0xffff),
[GDT_ENTRY_PNPBIOS_CS16] = GDT_ENTRY_INIT(DESC_CODE16, 0, 0xffff),
[GDT_ENTRY_PNPBIOS_DS] = GDT_ENTRY_INIT(DESC_DATA16, 0, 0xffff),
[GDT_ENTRY_PNPBIOS_TS1] = GDT_ENTRY_INIT(DESC_DATA16, 0, 0),
[GDT_ENTRY_PNPBIOS_TS2] = GDT_ENTRY_INIT(DESC_DATA16, 0, 0),
/*
* The APM segments have byte granularity and their bases
* are set at run time. All have 64k limits.
*/
/* 32-bit code */
[GDT_ENTRY_APMBIOS_BASE] = GDT_ENTRY_INIT(0x409a, 0, 0xffff),
/* 16-bit code */
[GDT_ENTRY_APMBIOS_BASE+1] = GDT_ENTRY_INIT(0x009a, 0, 0xffff),
/* data */
[GDT_ENTRY_APMBIOS_BASE+2] = GDT_ENTRY_INIT(0x4092, 0, 0xffff),
[GDT_ENTRY_ESPFIX_SS] = GDT_ENTRY_INIT(0xc092, 0, 0xfffff),
[GDT_ENTRY_PERCPU] = GDT_ENTRY_INIT(0xc092, 0, 0xfffff),
[GDT_ENTRY_APMBIOS_BASE] = GDT_ENTRY_INIT(DESC_CODE32_BIOS, 0, 0xffff),
[GDT_ENTRY_APMBIOS_BASE+1] = GDT_ENTRY_INIT(DESC_CODE16, 0, 0xffff),
[GDT_ENTRY_APMBIOS_BASE+2] = GDT_ENTRY_INIT(DESC_DATA32_BIOS, 0, 0xffff),
[GDT_ENTRY_ESPFIX_SS] = GDT_ENTRY_INIT(DESC_DATA32, 0, 0xfffff),
[GDT_ENTRY_PERCPU] = GDT_ENTRY_INIT(DESC_DATA32, 0, 0xfffff),
#endif
} };
EXPORT_PER_CPU_SYMBOL_GPL(gdt_page);
......
arch/x86/kernel/head64.c
View file @ 106b88d7
......@@ -71,9 +71,9 @@ EXPORT_SYMBOL(vmemmap_base);
* GDT used on the boot CPU before switching to virtual addresses.
*/
static struct desc_struct startup_gdt[GDT_ENTRIES] __initdata = {
[GDT_ENTRY_KERNEL32_CS] = GDT_ENTRY_INIT(0xc09b, 0, 0xfffff),
[GDT_ENTRY_KERNEL_CS] = GDT_ENTRY_INIT(0xa09b, 0, 0xfffff),
[GDT_ENTRY_KERNEL_DS] = GDT_ENTRY_INIT(0xc093, 0, 0xfffff),
[GDT_ENTRY_KERNEL32_CS] = GDT_ENTRY_INIT(DESC_CODE32, 0, 0xfffff),
[GDT_ENTRY_KERNEL_CS] = GDT_ENTRY_INIT(DESC_CODE64, 0, 0xfffff),
[GDT_ENTRY_KERNEL_DS] = GDT_ENTRY_INIT(DESC_DATA64, 0, 0xfffff),
};
/*
......
arch/x86/kernel/setup_percpu.c
View file @ 106b88d7
......@@ -106,8 +106,8 @@ void __init pcpu_populate_pte(unsigned long addr)
static inline void setup_percpu_segment(int cpu)
{
#ifdef CONFIG_X86_32
struct desc_struct d = GDT_ENTRY_INIT(0x8092, per_cpu_offset(cpu),
0xFFFFF);
struct desc_struct d = GDT_ENTRY_INIT(DESC_DATA32,
per_cpu_offset(cpu), 0xFFFFF);
write_gdt_entry(get_cpu_gdt_rw(cpu), GDT_ENTRY_PERCPU, &d, DESCTYPE_S);
#endif
......
arch/x86/platform/pvh/head.S
View file @ 106b88d7
......@@ -11,6 +11,7 @@
#include <linux/elfnote.h>
#include <linux/init.h>
#include <linux/linkage.h>
#include <asm/desc_defs.h>
#include <asm/segment.h>
#include <asm/asm.h>
#include <asm/boot.h>
......@@ -148,11 +149,11 @@ SYM_DATA_END(gdt)
SYM_DATA_START_LOCAL(gdt_start)
.quad 0x0000000000000000 /* NULL descriptor */
#ifdef CONFIG_X86_64
.quad GDT_ENTRY(0xa09a, 0, 0xfffff) /* PVH_CS_SEL */
.quad GDT_ENTRY(DESC_CODE64, 0, 0xfffff) /* PVH_CS_SEL */
#else
.quad GDT_ENTRY(0xc09a, 0, 0xfffff) /* PVH_CS_SEL */
.quad GDT_ENTRY(DESC_CODE32, 0, 0xfffff) /* PVH_CS_SEL */
#endif
.quad GDT_ENTRY(0xc092, 0, 0xfffff) /* PVH_DS_SEL */
.quad GDT_ENTRY(DESC_DATA32, 0, 0xfffff) /* PVH_DS_SEL */
SYM_DATA_END_LABEL(gdt_start, SYM_L_LOCAL, gdt_end)
.balign 16
......
arch/x86/realmode/rm/reboot.S
View file @ 106b88d7
/* SPDX-License-Identifier: GPL-2.0 */
#include <linux/linkage.h>
#include <asm/desc_defs.h>
#include <asm/segment.h>
#include <asm/page_types.h>
#include <asm/processor-flags.h>
......@@ -153,5 +154,5 @@ SYM_DATA_START(machine_real_restart_gdt)
* base value 0x100; since this is consistent with real mode
* semantics we don't have to reload the segments once CR0.PE = 0.
*/
.quad GDT_ENTRY(0x0093, 0x100, 0xffff)
.quad GDT_ENTRY(DESC_DATA16, 0x100, 0xffff)
SYM_DATA_END(machine_real_restart_gdt)
drivers/firmware/efi/libstub/x86-5lvl.c
View file @ 106b88d7
......@@ -13,8 +13,8 @@ bool efi_no5lvl;
static void (*la57_toggle)(void *cr3);
static const struct desc_struct gdt[] = {
[GDT_ENTRY_KERNEL32_CS] = GDT_ENTRY_INIT(0xc09b, 0, 0xfffff),
[GDT_ENTRY_KERNEL_CS] = GDT_ENTRY_INIT(0xa09b, 0, 0xfffff),
[GDT_ENTRY_KERNEL32_CS] = GDT_ENTRY_INIT(DESC_CODE32, 0, 0xfffff),
[GDT_ENTRY_KERNEL_CS] = GDT_ENTRY_INIT(DESC_CODE64, 0, 0xfffff),
};
/*
......
drivers/pnp/pnpbios/bioscalls.c
View file @ 106b88d7
......@@ -60,7 +60,7 @@ do { \
set_desc_limit(&gdt[(selname) >> 3], (size) - 1); \
} while(0)
static struct desc_struct bad_bios_desc = GDT_ENTRY_INIT(0x4092,
static struct desc_struct bad_bios_desc = GDT_ENTRY_INIT(DESC_DATA32_BIOS,
(unsigned long)__va(0x400UL), PAGE_SIZE - 0x400 - 1);
/*
......
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