cregit-Linux how code gets into the kernel

Release 4.14 arch/x86/include/asm/kexec.h

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _ASM_X86_KEXEC_H

#define _ASM_X86_KEXEC_H

#ifdef CONFIG_X86_32

# define PA_CONTROL_PAGE	0

# define VA_CONTROL_PAGE	1

# define PA_PGD			2

# define PA_SWAP_PAGE		3

# define PAGES_NR		4
#else

# define PA_CONTROL_PAGE	0

# define VA_CONTROL_PAGE	1

# define PA_TABLE_PAGE		2

# define PA_SWAP_PAGE		3

# define PAGES_NR		4
#endif


# define KEXEC_CONTROL_CODE_MAX_SIZE	2048

#ifndef __ASSEMBLY__

#include <linux/string.h>

#include <asm/page.h>
#include <asm/ptrace.h>
#include <asm/bootparam.h>

struct kimage;

/*
 * KEXEC_SOURCE_MEMORY_LIMIT maximum page get_free_page can return.
 * I.e. Maximum page that is mapped directly into kernel memory,
 * and kmap is not required.
 *
 * So far x86_64 is limited to 40 physical address bits.
 */
#ifdef CONFIG_X86_32
/* Maximum physical address we can use pages from */

# define KEXEC_SOURCE_MEMORY_LIMIT (-1UL)
/* Maximum address we can reach in physical address mode */

# define KEXEC_DESTINATION_MEMORY_LIMIT (-1UL)
/* Maximum address we can use for the control code buffer */

# define KEXEC_CONTROL_MEMORY_LIMIT TASK_SIZE


# define KEXEC_CONTROL_PAGE_SIZE	4096

/* The native architecture */

# define KEXEC_ARCH KEXEC_ARCH_386

/* We can also handle crash dumps from 64 bit kernel. */

# define vmcore_elf_check_arch_cross(x) ((x)->e_machine == EM_X86_64)
#else
/* Maximum physical address we can use pages from */

# define KEXEC_SOURCE_MEMORY_LIMIT      (MAXMEM-1)
/* Maximum address we can reach in physical address mode */

# define KEXEC_DESTINATION_MEMORY_LIMIT (MAXMEM-1)
/* Maximum address we can use for the control pages */

# define KEXEC_CONTROL_MEMORY_LIMIT     (MAXMEM-1)

/* Allocate one page for the pdp and the second for the code */

# define KEXEC_CONTROL_PAGE_SIZE  (4096UL + 4096UL)

/* The native architecture */

# define KEXEC_ARCH KEXEC_ARCH_X86_64
#endif

/* Memory to backup during crash kdump */

#define KEXEC_BACKUP_SRC_START	(0UL)

#define KEXEC_BACKUP_SRC_END	(640 * 1024UL)	
/* 640K */

/*
 * CPU does not save ss and sp on stack if execution is already
 * running in kernel mode at the time of NMI occurrence. This code
 * fixes it.
 */

static inline void crash_fixup_ss_esp(struct pt_regs *newregs, struct pt_regs *oldregs) { #ifdef CONFIG_X86_32 newregs->sp = (unsigned long)&(oldregs->sp); asm volatile("xorl %%eax, %%eax\n\t" "movw %%ss, %%ax\n\t" :"=a"(newregs->ss)); #endif }

Contributors

PersonTokensPropCommitsCommitProp
Harvey Harrison3792.50%150.00%
Joe Perches37.50%150.00%
Total40100.00%2100.00%

/* * This function is responsible for capturing register states if coming * via panic otherwise just fix up the ss and sp if coming via kernel * mode exception. */
static inline void crash_setup_regs(struct pt_regs *newregs, struct pt_regs *oldregs) { if (oldregs) { memcpy(newregs, oldregs, sizeof(*newregs)); crash_fixup_ss_esp(newregs, oldregs); } else { #ifdef CONFIG_X86_32 asm volatile("movl %%ebx,%0" : "=m"(newregs->bx)); asm volatile("movl %%ecx,%0" : "=m"(newregs->cx)); asm volatile("movl %%edx,%0" : "=m"(newregs->dx)); asm volatile("movl %%esi,%0" : "=m"(newregs->si)); asm volatile("movl %%edi,%0" : "=m"(newregs->di)); asm volatile("movl %%ebp,%0" : "=m"(newregs->bp)); asm volatile("movl %%eax,%0" : "=m"(newregs->ax)); asm volatile("movl %%esp,%0" : "=m"(newregs->sp)); asm volatile("movl %%ss, %%eax;" :"=a"(newregs->ss)); asm volatile("movl %%cs, %%eax;" :"=a"(newregs->cs)); asm volatile("movl %%ds, %%eax;" :"=a"(newregs->ds)); asm volatile("movl %%es, %%eax;" :"=a"(newregs->es)); asm volatile("pushfl; popl %0" :"=m"(newregs->flags)); #else asm volatile("movq %%rbx,%0" : "=m"(newregs->bx)); asm volatile("movq %%rcx,%0" : "=m"(newregs->cx)); asm volatile("movq %%rdx,%0" : "=m"(newregs->dx)); asm volatile("movq %%rsi,%0" : "=m"(newregs->si)); asm volatile("movq %%rdi,%0" : "=m"(newregs->di)); asm volatile("movq %%rbp,%0" : "=m"(newregs->bp)); asm volatile("movq %%rax,%0" : "=m"(newregs->ax)); asm volatile("movq %%rsp,%0" : "=m"(newregs->sp)); asm volatile("movq %%r8,%0" : "=m"(newregs->r8)); asm volatile("movq %%r9,%0" : "=m"(newregs->r9)); asm volatile("movq %%r10,%0" : "=m"(newregs->r10)); asm volatile("movq %%r11,%0" : "=m"(newregs->r11)); asm volatile("movq %%r12,%0" : "=m"(newregs->r12)); asm volatile("movq %%r13,%0" : "=m"(newregs->r13)); asm volatile("movq %%r14,%0" : "=m"(newregs->r14)); asm volatile("movq %%r15,%0" : "=m"(newregs->r15)); asm volatile("movl %%ss, %%eax;" :"=a"(newregs->ss)); asm volatile("movl %%cs, %%eax;" :"=a"(newregs->cs)); asm volatile("pushfq; popq %0" :"=m"(newregs->flags)); #endif newregs->ip = (unsigned long)current_text_addr(); } }

Contributors

PersonTokensPropCommitsCommitProp
Harvey Harrison9660.00%150.00%
Joe Perches6440.00%150.00%
Total160100.00%2100.00%

#ifdef CONFIG_X86_32 asmlinkage unsigned long relocate_kernel(unsigned long indirection_page, unsigned long control_page, unsigned long start_address, unsigned int has_pae, unsigned int preserve_context); #else unsigned long relocate_kernel(unsigned long indirection_page, unsigned long page_list, unsigned long start_address, unsigned int preserve_context, unsigned int sme_active); #endif #define ARCH_HAS_KIMAGE_ARCH #ifdef CONFIG_X86_32 struct kimage_arch { pgd_t *pgd; #ifdef CONFIG_X86_PAE pmd_t *pmd0; pmd_t *pmd1; #endif pte_t *pte0; pte_t *pte1; }; #else struct kimage_arch { p4d_t *p4d; pud_t *pud; pmd_t *pmd; pte_t *pte; /* Details of backup region */ unsigned long backup_src_start; unsigned long backup_src_sz; /* Physical address of backup segment */ unsigned long backup_load_addr; /* Core ELF header buffer */ void *elf_headers; unsigned long elf_headers_sz; unsigned long elf_load_addr; }; #endif /* CONFIG_X86_32 */ #ifdef CONFIG_X86_64 /* * Number of elements and order of elements in this structure should match * with the ones in arch/x86/purgatory/entry64.S. If you make a change here * make an appropriate change in purgatory too. */ struct kexec_entry64_regs { uint64_t rax; uint64_t rcx; uint64_t rdx; uint64_t rbx; uint64_t rsp; uint64_t rbp; uint64_t rsi; uint64_t rdi; uint64_t r8; uint64_t r9; uint64_t r10; uint64_t r11; uint64_t r12; uint64_t r13; uint64_t r14; uint64_t r15; uint64_t rip; }; extern int arch_kexec_post_alloc_pages(void *vaddr, unsigned int pages, gfp_t gfp); #define arch_kexec_post_alloc_pages arch_kexec_post_alloc_pages extern void arch_kexec_pre_free_pages(void *vaddr, unsigned int pages); #define arch_kexec_pre_free_pages arch_kexec_pre_free_pages #endif typedef void crash_vmclear_fn(void); extern crash_vmclear_fn __rcu *crash_vmclear_loaded_vmcss; extern void kdump_nmi_shootdown_cpus(void); #endif /* __ASSEMBLY__ */ #endif /* _ASM_X86_KEXEC_H */

Overall Contributors

PersonTokensPropCommitsCommitProp
Harvey Harrison27043.20%14.76%
Vivek Goyal10616.96%29.52%
Huang Ying10116.16%733.33%
Joe Perches6710.72%14.76%
Tom Lendacky416.56%29.52%
Zhang Yanfei132.08%29.52%
Thomas Gleixner91.44%14.76%
Hidehiro Kawai71.12%14.76%
Kirill A. Shutemov40.64%14.76%
H. Peter Anvin30.48%14.76%
Yinghai Lu30.48%14.76%
Greg Kroah-Hartman10.16%14.76%
Total625100.00%21100.00%
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