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b24413180f
kernel-ark/arch/x86/kernel/head_64.S
Greg Kroah-Hartman b24413180f License cleanup: add SPDX GPL-2.0 license identifier to files with no license 
Many source files in the tree are missing licensing information, which
makes it harder for compliance tools to determine the correct license.

By default all files without license information are under the default
license of the kernel, which is GPL version 2.

Update the files which contain no license information with the 'GPL-2.0'
SPDX license identifier.  The SPDX identifier is a legally binding
shorthand, which can be used instead of the full boiler plate text.

This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne.

How this work was done:

Patches were generated and checked against linux-4.14-rc6 for a subset of
the use cases:
 - file had no licensing information it it.
 - file was a */uapi/* one with no licensing information in it,
 - file was a */uapi/* one with existing licensing information,

Further patches will be generated in subsequent months to fix up cases
where non-standard license headers were used, and references to license
had to be inferred by heuristics based on keywords.

The analysis to determine which SPDX License Identifier to be applied to
a file was done in a spreadsheet of side by side results from of the
output of two independent scanners (ScanCode & Windriver) producing SPDX
tag:value files created by Philippe Ombredanne.  Philippe prepared the
base worksheet, and did an initial spot review of a few 1000 files.

The 4.13 kernel was the starting point of the analysis with 60,537 files
assessed.  Kate Stewart did a file by file comparison of the scanner
results in the spreadsheet to determine which SPDX license identifier(s)
to be applied to the file. She confirmed any determination that was not
immediately clear with lawyers working with the Linux Foundation.

Criteria used to select files for SPDX license identifier tagging was:
 - Files considered eligible had to be source code files.
 - Make and config files were included as candidates if they contained >5
   lines of source
 - File already had some variant of a license header in it (even if <5
   lines).

All documentation files were explicitly excluded.

The following heuristics were used to determine which SPDX license
identifiers to apply.

 - when both scanners couldn't find any license traces, file was
   considered to have no license information in it, and the top level
   COPYING file license applied.

   For non */uapi/* files that summary was:

   SPDX license identifier                            # files
   ---------------------------------------------------|-------
   GPL-2.0                                              11139

   and resulted in the first patch in this series.

   If that file was a */uapi/* path one, it was "GPL-2.0 WITH
   Linux-syscall-note" otherwise it was "GPL-2.0".  Results of that was:

   SPDX license identifier                            # files
   ---------------------------------------------------|-------
   GPL-2.0 WITH Linux-syscall-note                        930

   and resulted in the second patch in this series.

 - if a file had some form of licensing information in it, and was one
   of the */uapi/* ones, it was denoted with the Linux-syscall-note if
   any GPL family license was found in the file or had no licensing in
   it (per prior point).  Results summary:

   SPDX license identifier                            # files
   ---------------------------------------------------|------
   GPL-2.0 WITH Linux-syscall-note                       270
   GPL-2.0+ WITH Linux-syscall-note                      169
   ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause)    21
   ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause)    17
   LGPL-2.1+ WITH Linux-syscall-note                      15
   GPL-1.0+ WITH Linux-syscall-note                       14
   ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause)    5
   LGPL-2.0+ WITH Linux-syscall-note                       4
   LGPL-2.1 WITH Linux-syscall-note                        3
   ((GPL-2.0 WITH Linux-syscall-note) OR MIT)              3
   ((GPL-2.0 WITH Linux-syscall-note) AND MIT)             1

   and that resulted in the third patch in this series.

 - when the two scanners agreed on the detected license(s), that became
   the concluded license(s).

 - when there was disagreement between the two scanners (one detected a
   license but the other didn't, or they both detected different
   licenses) a manual inspection of the file occurred.

 - In most cases a manual inspection of the information in the file
   resulted in a clear resolution of the license that should apply (and
   which scanner probably needed to revisit its heuristics).

 - When it was not immediately clear, the license identifier was
   confirmed with lawyers working with the Linux Foundation.

 - If there was any question as to the appropriate license identifier,
   the file was flagged for further research and to be revisited later
   in time.

In total, over 70 hours of logged manual review was done on the
spreadsheet to determine the SPDX license identifiers to apply to the
source files by Kate, Philippe, Thomas and, in some cases, confirmation
by lawyers working with the Linux Foundation.

Kate also obtained a third independent scan of the 4.13 code base from
FOSSology, and compared selected files where the other two scanners
disagreed against that SPDX file, to see if there was new insights.  The
Windriver scanner is based on an older version of FOSSology in part, so
they are related.

Thomas did random spot checks in about 500 files from the spreadsheets
for the uapi headers and agreed with SPDX license identifier in the
files he inspected. For the non-uapi files Thomas did random spot checks
in about 15000 files.

In initial set of patches against 4.14-rc6, 3 files were found to have
copy/paste license identifier errors, and have been fixed to reflect the
correct identifier.

Additionally Philippe spent 10 hours this week doing a detailed manual
inspection and review of the 12,461 patched files from the initial patch
version early this week with:
 - a full scancode scan run, collecting the matched texts, detected
   license ids and scores
 - reviewing anything where there was a license detected (about 500+
   files) to ensure that the applied SPDX license was correct
 - reviewing anything where there was no detection but the patch license
   was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied
   SPDX license was correct

This produced a worksheet with 20 files needing minor correction.  This
worksheet was then exported into 3 different .csv files for the
different types of files to be modified.

These .csv files were then reviewed by Greg.  Thomas wrote a script to
parse the csv files and add the proper SPDX tag to the file, in the
format that the file expected.  This script was further refined by Greg
based on the output to detect more types of files automatically and to
distinguish between header and source .c files (which need different
comment types.)  Finally Greg ran the script using the .csv files to
generate the patches.

Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-02 11:10:55 +01:00

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/* SPDX-License-Identifier: GPL-2.0 */
/*
* linux/arch/x86/kernel/head_64.S -- start in 32bit and switch to 64bit
*
* Copyright (C) 2000 Andrea Arcangeli <andrea@suse.de> SuSE
* Copyright (C) 2000 Pavel Machek <pavel@suse.cz>
* Copyright (C) 2000 Karsten Keil <kkeil@suse.de>
* Copyright (C) 2001,2002 Andi Kleen <ak@suse.de>
* Copyright (C) 2005 Eric Biederman <ebiederm@xmission.com>
*/
#include <linux/linkage.h>
#include <linux/threads.h>
#include <linux/init.h>
#include <asm/segment.h>
#include <asm/pgtable.h>
#include <asm/page.h>
#include <asm/msr.h>
#include <asm/cache.h>
#include <asm/processor-flags.h>
#include <asm/percpu.h>
#include <asm/nops.h>
#include "../entry/calling.h"
#include <asm/export.h>
#ifdef CONFIG_PARAVIRT
#include <asm/asm-offsets.h>
#include <asm/paravirt.h>
#define GET_CR2_INTO(reg) GET_CR2_INTO_RAX ; movq %rax, reg
#else
#define GET_CR2_INTO(reg) movq %cr2, reg
#define INTERRUPT_RETURN iretq
#endif
/* we are not able to switch in one step to the final KERNEL ADDRESS SPACE
* because we need identity-mapped pages.
*
*/
#define p4d_index(x) (((x) >> P4D_SHIFT) & (PTRS_PER_P4D-1))
#define pud_index(x) (((x) >> PUD_SHIFT) & (PTRS_PER_PUD-1))
PGD_PAGE_OFFSET = pgd_index(__PAGE_OFFSET_BASE)
PGD_START_KERNEL = pgd_index(__START_KERNEL_map)
L3_START_KERNEL = pud_index(__START_KERNEL_map)
.text
__HEAD
.code64
.globl startup_64
startup_64:
/*
* At this point the CPU runs in 64bit mode CS.L = 1 CS.D = 0,
* and someone has loaded an identity mapped page table
* for us. These identity mapped page tables map all of the
* kernel pages and possibly all of memory.
*
* %rsi holds a physical pointer to real_mode_data.
*
* We come here either directly from a 64bit bootloader, or from
* arch/x86/boot/compressed/head_64.S.
*
* We only come here initially at boot nothing else comes here.
*
* Since we may be loaded at an address different from what we were
* compiled to run at we first fixup the physical addresses in our page
* tables and then reload them.
*/
/* Set up the stack for verify_cpu(), similar to initial_stack below */
leaq (__end_init_task - SIZEOF_PTREGS)(%rip), %rsp
/* Sanitize CPU configuration */
call verify_cpu
/*
* Perform pagetable fixups. Additionally, if SME is active, encrypt
* the kernel and retrieve the modifier (SME encryption mask if SME
* is active) to be added to the initial pgdir entry that will be
* programmed into CR3.
*/
leaq _text(%rip), %rdi
pushq %rsi
call __startup_64
popq %rsi
/* Form the CR3 value being sure to include the CR3 modifier */
addq $(early_top_pgt - __START_KERNEL_map), %rax
jmp 1f
ENTRY(secondary_startup_64)
/*
* At this point the CPU runs in 64bit mode CS.L = 1 CS.D = 0,
* and someone has loaded a mapped page table.
*
* %rsi holds a physical pointer to real_mode_data.
*
* We come here either from startup_64 (using physical addresses)
* or from trampoline.S (using virtual addresses).
*
* Using virtual addresses from trampoline.S removes the need
* to have any identity mapped pages in the kernel page table
* after the boot processor executes this code.
*/
/* Sanitize CPU configuration */
call verify_cpu
/*
* Retrieve the modifier (SME encryption mask if SME is active) to be
* added to the initial pgdir entry that will be programmed into CR3.
*/
pushq %rsi
call __startup_secondary_64
popq %rsi
/* Form the CR3 value being sure to include the CR3 modifier */
addq $(init_top_pgt - __START_KERNEL_map), %rax
1:
/* Enable PAE mode, PGE and LA57 */
movl $(X86_CR4_PAE | X86_CR4_PGE), %ecx
#ifdef CONFIG_X86_5LEVEL
orl $X86_CR4_LA57, %ecx
#endif
movq %rcx, %cr4
/* Setup early boot stage 4-/5-level pagetables. */
addq phys_base(%rip), %rax
movq %rax, %cr3
/* Ensure I am executing from virtual addresses */
movq $1f, %rax
jmp *%rax
1:
/* Check if nx is implemented */
movl $0x80000001, %eax
cpuid
movl %edx,%edi
/* Setup EFER (Extended Feature Enable Register) */
movl $MSR_EFER, %ecx
rdmsr
btsl $_EFER_SCE, %eax /* Enable System Call */
btl $20,%edi /* No Execute supported? */
jnc 1f
btsl $_EFER_NX, %eax
btsq $_PAGE_BIT_NX,early_pmd_flags(%rip)
1: wrmsr /* Make changes effective */
/* Setup cr0 */
#define CR0_STATE (X86_CR0_PE | X86_CR0_MP | X86_CR0_ET | \
X86_CR0_NE | X86_CR0_WP | X86_CR0_AM | \
X86_CR0_PG)
movl $CR0_STATE, %eax
/* Make changes effective */
movq %rax, %cr0
/* Setup a boot time stack */
movq initial_stack(%rip), %rsp
/* zero EFLAGS after setting rsp */
pushq $0
popfq
/*
* We must switch to a new descriptor in kernel space for the GDT
* because soon the kernel won't have access anymore to the userspace
* addresses where we're currently running on. We have to do that here
* because in 32bit we couldn't load a 64bit linear address.
*/
lgdt early_gdt_descr(%rip)
/* set up data segments */
xorl %eax,%eax
movl %eax,%ds
movl %eax,%ss
movl %eax,%es
/*
* We don't really need to load %fs or %gs, but load them anyway
* to kill any stale realmode selectors. This allows execution
* under VT hardware.
*/
movl %eax,%fs
movl %eax,%gs
/* Set up %gs.
*
* The base of %gs always points to the bottom of the irqstack
* union. If the stack protector canary is enabled, it is
* located at %gs:40. Note that, on SMP, the boot cpu uses
* init data section till per cpu areas are set up.
*/
movl $MSR_GS_BASE,%ecx
movl initial_gs(%rip),%eax
movl initial_gs+4(%rip),%edx
wrmsr
/* rsi is pointer to real mode structure with interesting info.
pass it to C */
movq %rsi, %rdi
.Ljump_to_C_code:
/*
* Jump to run C code and to be on a real kernel address.
* Since we are running on identity-mapped space we have to jump
* to the full 64bit address, this is only possible as indirect
* jump. In addition we need to ensure %cs is set so we make this
* a far return.
*
* Note: do not change to far jump indirect with 64bit offset.
*
* AMD does not support far jump indirect with 64bit offset.
* AMD64 Architecture Programmer's Manual, Volume 3: states only
* JMP FAR mem16:16 FF /5 Far jump indirect,
* with the target specified by a far pointer in memory.
* JMP FAR mem16:32 FF /5 Far jump indirect,
* with the target specified by a far pointer in memory.
*
* Intel64 does support 64bit offset.
* Software Developer Manual Vol 2: states:
* FF /5 JMP m16:16 Jump far, absolute indirect,
* address given in m16:16
* FF /5 JMP m16:32 Jump far, absolute indirect,
* address given in m16:32.
* REX.W + FF /5 JMP m16:64 Jump far, absolute indirect,
* address given in m16:64.
*/
pushq $.Lafter_lret # put return address on stack for unwinder
xorq %rbp, %rbp # clear frame pointer
movq initial_code(%rip), %rax
pushq $__KERNEL_CS # set correct cs
pushq %rax # target address in negative space
lretq
.Lafter_lret:
ENDPROC(secondary_startup_64)
#include "verify_cpu.S"
#ifdef CONFIG_HOTPLUG_CPU
/*
* Boot CPU0 entry point. It's called from play_dead(). Everything has been set
* up already except stack. We just set up stack here. Then call
* start_secondary() via .Ljump_to_C_code.
*/
ENTRY(start_cpu0)
movq initial_stack(%rip), %rsp
jmp .Ljump_to_C_code
ENDPROC(start_cpu0)
#endif
/* 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(irq_stack_union)
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
__FINITDATA
bad_address:
jmp bad_address
__INIT
ENTRY(early_idt_handler_array)
# 104(%rsp) %rflags
# 96(%rsp) %cs
# 88(%rsp) %rip
# 80(%rsp) error code
i = 0
.rept NUM_EXCEPTION_VECTORS
.ifeq (EXCEPTION_ERRCODE_MASK >> i) & 1
pushq $0 # Dummy error code, to make stack frame uniform
.endif
pushq $i # 72(%rsp) Vector number
jmp early_idt_handler_common
i = i + 1
.fill early_idt_handler_array + i*EARLY_IDT_HANDLER_SIZE - ., 1, 0xcc
.endr
ENDPROC(early_idt_handler_array)
early_idt_handler_common:
/*
* The stack is the hardware frame, an error code or zero, and the
* vector number.
*/
cld
incl early_recursion_flag(%rip)
/* The vector number is currently in the pt_regs->di slot. */
pushq %rsi /* pt_regs->si */
movq 8(%rsp), %rsi /* RSI = vector number */
movq %rdi, 8(%rsp) /* pt_regs->di = RDI */
pushq %rdx /* pt_regs->dx */
pushq %rcx /* pt_regs->cx */
pushq %rax /* pt_regs->ax */
pushq %r8 /* pt_regs->r8 */
pushq %r9 /* pt_regs->r9 */
pushq %r10 /* pt_regs->r10 */
pushq %r11 /* pt_regs->r11 */
pushq %rbx /* pt_regs->bx */
pushq %rbp /* pt_regs->bp */
pushq %r12 /* pt_regs->r12 */
pushq %r13 /* pt_regs->r13 */
pushq %r14 /* pt_regs->r14 */
pushq %r15 /* pt_regs->r15 */
cmpq $14,%rsi /* Page fault? */
jnz 10f
GET_CR2_INTO(%rdi) /* Can clobber any volatile register if pv */
call early_make_pgtable
andl %eax,%eax
jz 20f /* All good */
10:
movq %rsp,%rdi /* RDI = pt_regs; RSI is already trapnr */
call early_fixup_exception
20:
decl early_recursion_flag(%rip)
jmp restore_regs_and_iret
ENDPROC(early_idt_handler_common)
__INITDATA
.balign 4
GLOBAL(early_recursion_flag)
.long 0
#define NEXT_PAGE(name) \
.balign PAGE_SIZE; \
GLOBAL(name)
/* Automate the creation of 1 to 1 mapping pmd entries */
#define PMDS(START, PERM, COUNT) \
i = 0 ; \
.rept (COUNT) ; \
.quad (START) + (i << PMD_SHIFT) + (PERM) ; \
i = i + 1 ; \
.endr
__INITDATA
NEXT_PAGE(early_top_pgt)
.fill 511,8,0
#ifdef CONFIG_X86_5LEVEL
.quad level4_kernel_pgt - __START_KERNEL_map + _PAGE_TABLE_NOENC
#else
.quad level3_kernel_pgt - __START_KERNEL_map + _PAGE_TABLE_NOENC
#endif
NEXT_PAGE(early_dynamic_pgts)
.fill 512*EARLY_DYNAMIC_PAGE_TABLES,8,0
.data
#ifndef CONFIG_XEN
NEXT_PAGE(init_top_pgt)
.fill 512,8,0
#else
NEXT_PAGE(init_top_pgt)
.quad level3_ident_pgt - __START_KERNEL_map + _KERNPG_TABLE_NOENC
.org init_top_pgt + PGD_PAGE_OFFSET*8, 0
.quad level3_ident_pgt - __START_KERNEL_map + _KERNPG_TABLE_NOENC
.org init_top_pgt + PGD_START_KERNEL*8, 0
/* (2^48-(2*1024*1024*1024))/(2^39) = 511 */
.quad level3_kernel_pgt - __START_KERNEL_map + _PAGE_TABLE_NOENC
NEXT_PAGE(level3_ident_pgt)
.quad level2_ident_pgt - __START_KERNEL_map + _KERNPG_TABLE_NOENC
.fill 511, 8, 0
NEXT_PAGE(level2_ident_pgt)
/* Since I easily can, map the first 1G.
* Don't set NX because code runs from these pages.
*/
PMDS(0, __PAGE_KERNEL_IDENT_LARGE_EXEC, PTRS_PER_PMD)
#endif
#ifdef CONFIG_X86_5LEVEL
NEXT_PAGE(level4_kernel_pgt)
.fill 511,8,0
.quad level3_kernel_pgt - __START_KERNEL_map + _PAGE_TABLE_NOENC
#endif
NEXT_PAGE(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
NEXT_PAGE(level2_kernel_pgt)
/*
* 512 MB kernel mapping. We spend a full page on this pagetable
* anyway.
*
* The kernel code+data+bss must not be bigger than that.
*
* (NOTE: at +512MB starts the module area, see MODULES_VADDR.
* If you want to increase this then increase MODULES_VADDR
* too.)
*/
PMDS(0, __PAGE_KERNEL_LARGE_EXEC,
KERNEL_IMAGE_SIZE/PMD_SIZE)
NEXT_PAGE(level2_fixmap_pgt)
.fill 506,8,0
.quad level1_fixmap_pgt - __START_KERNEL_map + _PAGE_TABLE_NOENC
/* 8MB reserved for vsyscalls + a 2MB hole = 4 + 1 entries */
.fill 5,8,0
NEXT_PAGE(level1_fixmap_pgt)
.fill 512,8,0
#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
EXPORT_SYMBOL(phys_base)
#include "../../x86/xen/xen-head.S"
__PAGE_ALIGNED_BSS
NEXT_PAGE(empty_zero_page)
.skip PAGE_SIZE
EXPORT_SYMBOL(empty_zero_page)
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