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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 <jslaby@suse.cz>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Cao jin <caoj.fnst@cn.fujitsu.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: linux-arch@vger.kernel.org
Cc: Maran Wilson <maran.wilson@oracle.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: x86-ml <x86@kernel.org>
Link: https://lkml.kernel.org/r/20191011115108.12392-12-jslaby@suse.cz
This commit is contained in:
Jiri Slaby 2019-10-11 13:50:51 +02:00 committed by Borislav Petkov
parent cc66936e50
commit b1bd27b9ad
2 changed files with 64 additions and 56 deletions
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35
arch/x86/kernel/head_32.S
View File

@ -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)

85
arch/x86/kernel/head_64.S
View File

@ -260,16 +260,14 @@ END(start_cpu0)
/* Both SMP bootup and ACPI suspend change these variables */
__REFDATA
.balign 8
GLOBAL(initial_code)
.quad x86_64_start_kernel
GLOBAL(initial_gs)
.quad INIT_PER_CPU_VAR(fixed_percpu_data)
GLOBAL(initial_stack)
/*
* The SIZEOF_PTREGS gap is a convention which helps the in-kernel
* unwinder reliably detect the end of the stack.
*/
.quad init_thread_union + THREAD_SIZE - SIZEOF_PTREGS
SYM_DATA(initial_code, .quad x86_64_start_kernel)
SYM_DATA(initial_gs, .quad INIT_PER_CPU_VAR(fixed_percpu_data))
/*
* The SIZEOF_PTREGS gap is a convention which helps the in-kernel unwinder
* reliably detect the end of the stack.
*/
SYM_DATA(initial_stack, .quad init_thread_union + THREAD_SIZE - SIZEOF_PTREGS)
__FINITDATA
__INIT
@ -335,9 +333,9 @@ SYM_CODE_START_LOCAL(early_idt_handler_common)
jmp restore_regs_and_return_to_kernel
SYM_CODE_END(early_idt_handler_common)
#define NEXT_PAGE(name) \
.balign PAGE_SIZE; \
GLOBAL(name)
#define SYM_DATA_START_PAGE_ALIGNED(name) \
SYM_START(name, SYM_L_GLOBAL, .balign PAGE_SIZE)
#ifdef CONFIG_PAGE_TABLE_ISOLATION
/*
@ -352,11 +350,11 @@ GLOBAL(name)
*/
#define PTI_USER_PGD_FILL 512
/* This ensures they are 8k-aligned: */
#define NEXT_PGD_PAGE(name) \
.balign 2 * PAGE_SIZE; \
GLOBAL(name)
#define SYM_DATA_START_PTI_ALIGNED(name) \
SYM_START(name, SYM_L_GLOBAL, .balign 2 * PAGE_SIZE)
#else
#define NEXT_PGD_PAGE(name) NEXT_PAGE(name)
#define SYM_DATA_START_PTI_ALIGNED(name) \
SYM_DATA_START_PAGE_ALIGNED(name)
#define PTI_USER_PGD_FILL 0
#endif
@ -371,20 +369,21 @@ GLOBAL(name)
__INITDATA
.balign 4
NEXT_PGD_PAGE(early_top_pgt)
SYM_DATA_START_PTI_ALIGNED(early_top_pgt)
.fill 512,8,0
.fill PTI_USER_PGD_FILL,8,0
SYM_DATA_END(early_top_pgt)
NEXT_PAGE(early_dynamic_pgts)
SYM_DATA_START_PAGE_ALIGNED(early_dynamic_pgts)
.fill 512*EARLY_DYNAMIC_PAGE_TABLES,8,0
SYM_DATA_END(early_dynamic_pgts)
GLOBAL(early_recursion_flag)
.long 0
SYM_DATA(early_recursion_flag, .long 0)
.data
#if defined(CONFIG_XEN_PV) || defined(CONFIG_PVH)
NEXT_PGD_PAGE(init_top_pgt)
SYM_DATA_START_PTI_ALIGNED(init_top_pgt)
.quad level3_ident_pgt - __START_KERNEL_map + _KERNPG_TABLE_NOENC
.org init_top_pgt + L4_PAGE_OFFSET*8, 0
.quad level3_ident_pgt - __START_KERNEL_map + _KERNPG_TABLE_NOENC
@ -392,11 +391,13 @@ NEXT_PGD_PAGE(init_top_pgt)
/* (2^48-(2*1024*1024*1024))/(2^39) = 511 */
.quad level3_kernel_pgt - __START_KERNEL_map + _PAGE_TABLE_NOENC
.fill PTI_USER_PGD_FILL,8,0
SYM_DATA_END(init_top_pgt)
NEXT_PAGE(level3_ident_pgt)
SYM_DATA_START_PAGE_ALIGNED(level3_ident_pgt)
.quad level2_ident_pgt - __START_KERNEL_map + _KERNPG_TABLE_NOENC
.fill 511, 8, 0
NEXT_PAGE(level2_ident_pgt)
SYM_DATA_END(level3_ident_pgt)
SYM_DATA_START_PAGE_ALIGNED(level2_ident_pgt)
/*
* Since I easily can, map the first 1G.
* Don't set NX because code runs from these pages.
@ -406,25 +407,29 @@ NEXT_PAGE(level2_ident_pgt)
* the CPU should ignore the bit.
*/
PMDS(0, __PAGE_KERNEL_IDENT_LARGE_EXEC, PTRS_PER_PMD)
SYM_DATA_END(level2_ident_pgt)
#else
NEXT_PGD_PAGE(init_top_pgt)
SYM_DATA_START_PTI_ALIGNED(init_top_pgt)
.fill 512,8,0
.fill PTI_USER_PGD_FILL,8,0
SYM_DATA_END(init_top_pgt)
#endif
#ifdef CONFIG_X86_5LEVEL
NEXT_PAGE(level4_kernel_pgt)
SYM_DATA_START_PAGE_ALIGNED(level4_kernel_pgt)
.fill 511,8,0
.quad level3_kernel_pgt - __START_KERNEL_map + _PAGE_TABLE_NOENC
SYM_DATA_END(level4_kernel_pgt)
#endif
NEXT_PAGE(level3_kernel_pgt)
SYM_DATA_START_PAGE_ALIGNED(level3_kernel_pgt)
.fill L3_START_KERNEL,8,0
/* (2^48-(2*1024*1024*1024)-((2^39)*511))/(2^30) = 510 */
.quad level2_kernel_pgt - __START_KERNEL_map + _KERNPG_TABLE_NOENC
.quad level2_fixmap_pgt - __START_KERNEL_map + _PAGE_TABLE_NOENC
SYM_DATA_END(level3_kernel_pgt)
NEXT_PAGE(level2_kernel_pgt)
SYM_DATA_START_PAGE_ALIGNED(level2_kernel_pgt)
/*
* 512 MB kernel mapping. We spend a full page on this pagetable
* anyway.
@ -441,8 +446,9 @@ NEXT_PAGE(level2_kernel_pgt)
*/
PMDS(0, __PAGE_KERNEL_LARGE_EXEC,
KERNEL_IMAGE_SIZE/PMD_SIZE)
SYM_DATA_END(level2_kernel_pgt)
NEXT_PAGE(level2_fixmap_pgt)
SYM_DATA_START_PAGE_ALIGNED(level2_fixmap_pgt)
.fill (512 - 4 - FIXMAP_PMD_NUM),8,0
pgtno = 0
.rept (FIXMAP_PMD_NUM)
@ -452,31 +458,32 @@ NEXT_PAGE(level2_fixmap_pgt)
.endr
/* 6 MB reserved space + a 2MB hole */
.fill 4,8,0
SYM_DATA_END(level2_fixmap_pgt)
NEXT_PAGE(level1_fixmap_pgt)
SYM_DATA_START_PAGE_ALIGNED(level1_fixmap_pgt)
.rept (FIXMAP_PMD_NUM)
.fill 512,8,0
.endr
SYM_DATA_END(level1_fixmap_pgt)
#undef PMDS
.data
.align 16
.globl early_gdt_descr
early_gdt_descr:
.word GDT_ENTRIES*8-1
early_gdt_descr_base:
.quad INIT_PER_CPU_VAR(gdt_page)
ENTRY(phys_base)
/* This must match the first entry in level2_kernel_pgt */
.quad 0x0000000000000000
SYM_DATA(early_gdt_descr, .word GDT_ENTRIES*8-1)
SYM_DATA_LOCAL(early_gdt_descr_base, .quad INIT_PER_CPU_VAR(gdt_page))
.align 16
/* This must match the first entry in level2_kernel_pgt */
SYM_DATA(phys_base, .quad 0x0)
EXPORT_SYMBOL(phys_base)
#include "../../x86/xen/xen-head.S"
__PAGE_ALIGNED_BSS
NEXT_PAGE(empty_zero_page)
SYM_DATA_START_PAGE_ALIGNED(empty_zero_page)
.skip PAGE_SIZE
SYM_DATA_END(empty_zero_page)
EXPORT_SYMBOL(empty_zero_page)