From b1bd27b9ad45d77a2924e2168c6982c8ff1d8083 Mon Sep 17 00:00:00 2001 From: Jiri Slaby Date: Fri, 11 Oct 2019 13:50:51 +0200 Subject: x86/asm/head: Annotate data appropriately Use the new SYM_DATA, SYM_DATA_START, and SYM_DATA_END in both 32 and 64 bit head_*.S. In the 64-bit version, define also SYM_DATA_START_PAGE_ALIGNED locally using the new SYM_START. It is used in the code instead of NEXT_PAGE() which was defined in this file and had been using the obsolete macro GLOBAL(). Now, the data in the 64-bit object file look sane: Value Size Type Bind Vis Ndx Name 0000 4096 OBJECT GLOBAL DEFAULT 15 init_level4_pgt 1000 4096 OBJECT GLOBAL DEFAULT 15 level3_kernel_pgt 2000 2048 OBJECT GLOBAL DEFAULT 15 level2_kernel_pgt 3000 4096 OBJECT GLOBAL DEFAULT 15 level2_fixmap_pgt 4000 4096 OBJECT GLOBAL DEFAULT 15 level1_fixmap_pgt 5000 2 OBJECT GLOBAL DEFAULT 15 early_gdt_descr 5002 8 OBJECT LOCAL DEFAULT 15 early_gdt_descr_base 500a 8 OBJECT GLOBAL DEFAULT 15 phys_base 0000 8 OBJECT GLOBAL DEFAULT 17 initial_code 0008 8 OBJECT GLOBAL DEFAULT 17 initial_gs 0010 8 OBJECT GLOBAL DEFAULT 17 initial_stack 0000 4 OBJECT GLOBAL DEFAULT 19 early_recursion_flag 1000 4096 OBJECT GLOBAL DEFAULT 19 early_level4_pgt 2000 0x40000 OBJECT GLOBAL DEFAULT 19 early_dynamic_pgts 0000 4096 OBJECT GLOBAL DEFAULT 22 empty_zero_page All have correct size and type now. Note that this also removes implicit 16B alignment previously inserted by ENTRY: * initial_code, setup_once_ref, initial_page_table, initial_stack, boot_gdt are still aligned * early_gdt_descr is now properly aligned as was intended before ENTRY was added there long time ago * phys_base's alignment is kept by an explicitly added new alignment Signed-off-by: Jiri Slaby Signed-off-by: Borislav Petkov Cc: Andy Lutomirski Cc: Cao jin Cc: "H. Peter Anvin" Cc: Ingo Molnar Cc: Josh Poimboeuf Cc: Juergen Gross Cc: linux-arch@vger.kernel.org Cc: Maran Wilson Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: x86-ml Link: https://lkml.kernel.org/r/20191011115108.12392-12-jslaby@suse.cz --- arch/x86/kernel/head_32.S | 35 ++++++++++++++++++----------------- 1 file changed, 18 insertions(+), 17 deletions(-) (limited to 'arch/x86/kernel/head_32.S') diff --git a/arch/x86/kernel/head_32.S b/arch/x86/kernel/head_32.S index aec1fdb80221..e2b3e6cf86ca 100644 --- a/arch/x86/kernel/head_32.S +++ b/arch/x86/kernel/head_32.S @@ -502,15 +502,12 @@ ENDPROC(early_ignore_irq) __INITDATA .align 4 -GLOBAL(early_recursion_flag) - .long 0 +SYM_DATA(early_recursion_flag, .long 0) __REFDATA .align 4 -ENTRY(initial_code) - .long i386_start_kernel -ENTRY(setup_once_ref) - .long setup_once +SYM_DATA(initial_code, .long i386_start_kernel) +SYM_DATA(setup_once_ref, .long setup_once) #ifdef CONFIG_PAGE_TABLE_ISOLATION #define PGD_ALIGN (2 * PAGE_SIZE) @@ -553,7 +550,7 @@ EXPORT_SYMBOL(empty_zero_page) __PAGE_ALIGNED_DATA /* Page-aligned for the benefit of paravirt? */ .align PGD_ALIGN -ENTRY(initial_page_table) +SYM_DATA_START(initial_page_table) .long pa(initial_pg_pmd+PGD_IDENT_ATTR),0 /* low identity map */ # if KPMDS == 3 .long pa(initial_pg_pmd+PGD_IDENT_ATTR),0 @@ -571,17 +568,18 @@ ENTRY(initial_page_table) # error "Kernel PMDs should be 1, 2 or 3" # endif .align PAGE_SIZE /* needs to be page-sized too */ +SYM_DATA_END(initial_page_table) #endif .data .balign 4 -ENTRY(initial_stack) - /* - * The SIZEOF_PTREGS gap is a convention which helps the in-kernel - * unwinder reliably detect the end of the stack. - */ - .long init_thread_union + THREAD_SIZE - SIZEOF_PTREGS - \ - TOP_OF_KERNEL_STACK_PADDING; +/* + * The SIZEOF_PTREGS gap is a convention which helps the in-kernel unwinder + * reliably detect the end of the stack. + */ +SYM_DATA(initial_stack, + .long init_thread_union + THREAD_SIZE - + SIZEOF_PTREGS - TOP_OF_KERNEL_STACK_PADDING) __INITRODATA int_msg: @@ -600,22 +598,25 @@ int_msg: ALIGN # early boot GDT descriptor (must use 1:1 address mapping) .word 0 # 32 bit align gdt_desc.address -boot_gdt_descr: +SYM_DATA_START_LOCAL(boot_gdt_descr) .word __BOOT_DS+7 .long boot_gdt - __PAGE_OFFSET +SYM_DATA_END(boot_gdt_descr) # boot GDT descriptor (later on used by CPU#0): .word 0 # 32 bit align gdt_desc.address -ENTRY(early_gdt_descr) +SYM_DATA_START(early_gdt_descr) .word GDT_ENTRIES*8-1 .long gdt_page /* Overwritten for secondary CPUs */ +SYM_DATA_END(early_gdt_descr) /* * The boot_gdt must mirror the equivalent in setup.S and is * used only for booting. */ .align L1_CACHE_BYTES -ENTRY(boot_gdt) +SYM_DATA_START(boot_gdt) .fill GDT_ENTRY_BOOT_CS,8,0 .quad 0x00cf9a000000ffff /* kernel 4GB code at 0x00000000 */ .quad 0x00cf92000000ffff /* kernel 4GB data at 0x00000000 */ +SYM_DATA_END(boot_gdt) -- cgit