From 41ef75c848e33beb1f7b981866b62b0066f744c7 Mon Sep 17 00:00:00 2001 From: Vegard Nossum Date: Tue, 19 Dec 2023 16:11:57 +0100 Subject: x86/asm: Replace magic numbers in GDT descriptors, preparations We'd like to replace all the magic numbers in various GDT descriptors with new, semantically meaningful, symbolic values. In order to be able to verify that the change doesn't cause any actual changes to the compiled binary code, I've split the change into two patches: - Part 1 (this commit): everything _but_ actually replacing the numbers - Part 2 (the following commit): _only_ replacing the numbers The reason we need this split for verification is that including new headers causes some spurious changes to the object files, mostly line number changes in the debug info but occasionally other subtle codegen changes. Signed-off-by: Vegard Nossum Signed-off-by: Ingo Molnar Acked-by: Linus Torvalds Link: https://lore.kernel.org/r/20231219151200.2878271-3-vegard.nossum@oracle.com --- arch/x86/kernel/cpu/common.c | 8 -------- 1 file changed, 8 deletions(-) (limited to 'arch/x86/kernel/cpu/common.c') diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c index b14fc8c1c953..ceb6e4b6d57e 100644 --- a/arch/x86/kernel/cpu/common.c +++ b/arch/x86/kernel/cpu/common.c @@ -204,25 +204,17 @@ DEFINE_PER_CPU_PAGE_ALIGNED(struct gdt_page, gdt_page) = { .gdt = { * 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), /* * 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), -- cgit