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Date: Tue, 19 Dec 2023 16:11:58 +0100
From: Vegard Nossum <vegard.nossum@...cle.com>
To: Thomas Gleixner <tglx@...utronix.de>, Ingo Molnar <mingo@...hat.com>,
Borislav Petkov <bp@...en8.de>,
Dave Hansen <dave.hansen@...ux.intel.com>, x86@...nel.org
Cc: "H. Peter Anvin" <hpa@...or.com>, linux-kernel@...r.kernel.org,
Brian Gerst <brgerst@...il.com>, Peter Zijlstra <peterz@...radead.org>,
Linus Torvalds <torvalds@...uxfoundation.org>,
Vegard Nossum <vegard.nossum@...cle.com>
Subject: [PATCH 3/5] x86: replace magic numbers in GDT descriptors, part 2
Actually replace the numeric values by the new symbolic values.
I used this to find all the existing users of the GDT_ENTRY*() macros:
$ git grep -P 'GDT_ENTRY(_INIT)?\('
Some of the lines will exceed 80 characters, but some of them will be
shorter again in the next couple of patches.
Link: https://lore.kernel.org/all/CAHk-=wib5XLebuEra7y2YH96wxdk=8vJnA8XoVq0FExpzVvN=Q@mail.gmail.com/
Signed-off-by: Vegard Nossum <vegard.nossum@...cle.com>
---
arch/x86/boot/pm.c | 6 ++--
arch/x86/kernel/apm_32.c | 2 +-
arch/x86/kernel/cpu/common.c | 40 ++++++++++++-------------
arch/x86/kernel/head64.c | 6 ++--
arch/x86/kernel/setup_percpu.c | 4 +--
arch/x86/platform/pvh/head.S | 6 ++--
arch/x86/realmode/rm/reboot.S | 2 +-
drivers/firmware/efi/libstub/x86-5lvl.c | 4 +--
drivers/pnp/pnpbios/bioscalls.c | 2 +-
9 files changed, 36 insertions(+), 36 deletions(-)
diff --git a/arch/x86/boot/pm.c b/arch/x86/boot/pm.c
index 0361b5307bd8..ab35b52d2c4b 100644
--- a/arch/x86/boot/pm.c
+++ b/arch/x86/boot/pm.c
@@ -68,13 +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 | _DESC_ACCESSED, 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 | _DESC_ACCESSED, 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
diff --git a/arch/x86/kernel/apm_32.c b/arch/x86/kernel/apm_32.c
index 5934ee5bc087..76a5ced278c2 100644
--- a/arch/x86/kernel/apm_32.c
+++ b/arch/x86/kernel/apm_32.c
@@ -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 */
diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c
index ceb6e4b6d57e..32934a0656af 100644
--- a/arch/x86/kernel/cpu/common.c
+++ b/arch/x86/kernel/cpu/common.c
@@ -188,37 +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 | _DESC_ACCESSED, 0, 0xfffff),
+ [GDT_ENTRY_KERNEL_CS] = GDT_ENTRY_INIT(DESC_CODE64 | _DESC_ACCESSED, 0, 0xfffff),
+ [GDT_ENTRY_KERNEL_DS] = GDT_ENTRY_INIT(DESC_DATA64 | _DESC_ACCESSED, 0, 0xfffff),
+ [GDT_ENTRY_DEFAULT_USER32_CS] = GDT_ENTRY_INIT(DESC_CODE32 | DESC_USER | _DESC_ACCESSED, 0, 0xfffff),
+ [GDT_ENTRY_DEFAULT_USER_DS] = GDT_ENTRY_INIT(DESC_DATA64 | DESC_USER | _DESC_ACCESSED, 0, 0xfffff),
+ [GDT_ENTRY_DEFAULT_USER_CS] = GDT_ENTRY_INIT(DESC_CODE64 | DESC_USER | _DESC_ACCESSED, 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.
*/
- [GDT_ENTRY_PNPBIOS_CS32] = GDT_ENTRY_INIT(0x409a, 0, 0xffff),
- [GDT_ENTRY_PNPBIOS_CS16] = GDT_ENTRY_INIT(0x009a, 0, 0xffff),
- [GDT_ENTRY_PNPBIOS_DS] = GDT_ENTRY_INIT(0x0092, 0, 0xffff),
- [GDT_ENTRY_PNPBIOS_TS1] = GDT_ENTRY_INIT(0x0092, 0, 0),
- [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.
*/
- [GDT_ENTRY_APMBIOS_BASE] = GDT_ENTRY_INIT(0x409a, 0, 0xffff),
- [GDT_ENTRY_APMBIOS_BASE+1] = GDT_ENTRY_INIT(0x009a, 0, 0xffff),
- [GDT_ENTRY_APMBIOS_BASE+2] = GDT_ENTRY_INIT(0x4092, 0, 0xffff),
+ [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(0xc092, 0, 0xfffff),
- [GDT_ENTRY_PERCPU] = GDT_ENTRY_INIT(0xc092, 0, 0xfffff),
+ [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);
diff --git a/arch/x86/kernel/head64.c b/arch/x86/kernel/head64.c
index 05a110c97111..00dbddfdfece 100644
--- a/arch/x86/kernel/head64.c
+++ b/arch/x86/kernel/head64.c
@@ -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 | _DESC_ACCESSED, 0, 0xfffff),
+ [GDT_ENTRY_KERNEL_CS] = GDT_ENTRY_INIT(DESC_CODE64 | _DESC_ACCESSED, 0, 0xfffff),
+ [GDT_ENTRY_KERNEL_DS] = GDT_ENTRY_INIT(DESC_DATA64 | _DESC_ACCESSED, 0, 0xfffff),
};
/*
diff --git a/arch/x86/kernel/setup_percpu.c b/arch/x86/kernel/setup_percpu.c
index 2c97bf7b56ae..f2583de97a64 100644
--- a/arch/x86/kernel/setup_percpu.c
+++ b/arch/x86/kernel/setup_percpu.c
@@ -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 & ~_DESC_DB,
+ per_cpu_offset(cpu), 0xFFFFF);
write_gdt_entry(get_cpu_gdt_rw(cpu), GDT_ENTRY_PERCPU, &d, DESCTYPE_S);
#endif
diff --git a/arch/x86/platform/pvh/head.S b/arch/x86/platform/pvh/head.S
index 9bcafdded2a1..7c6a1089ce1c 100644
--- a/arch/x86/platform/pvh/head.S
+++ b/arch/x86/platform/pvh/head.S
@@ -149,11 +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
diff --git a/arch/x86/realmode/rm/reboot.S b/arch/x86/realmode/rm/reboot.S
index 447641820a8d..5bc068b9acdd 100644
--- a/arch/x86/realmode/rm/reboot.S
+++ b/arch/x86/realmode/rm/reboot.S
@@ -154,5 +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 | _DESC_ACCESSED, 0x100, 0xffff)
SYM_DATA_END(machine_real_restart_gdt)
diff --git a/drivers/firmware/efi/libstub/x86-5lvl.c b/drivers/firmware/efi/libstub/x86-5lvl.c
index 479dd445acdc..005dd9b14f95 100644
--- a/drivers/firmware/efi/libstub/x86-5lvl.c
+++ b/drivers/firmware/efi/libstub/x86-5lvl.c
@@ -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 | _DESC_ACCESSED, 0, 0xfffff),
+ [GDT_ENTRY_KERNEL_CS] = GDT_ENTRY_INIT(DESC_CODE64 | _DESC_ACCESSED, 0, 0xfffff),
};
/*
diff --git a/drivers/pnp/pnpbios/bioscalls.c b/drivers/pnp/pnpbios/bioscalls.c
index ddc6f2163c8e..1f31dce5835a 100644
--- a/drivers/pnp/pnpbios/bioscalls.c
+++ b/drivers/pnp/pnpbios/bioscalls.c
@@ -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);
/*
--
2.34.1
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