linux_dsm_epyc7002/arch/x86/include/asm/kexec.h
Peter Zijlstra 3c88c692c2 x86/stackframe/32: Provide consistent pt_regs
Currently pt_regs on x86_32 has an oddity in that kernel regs
(!user_mode(regs)) are short two entries (esp/ss). This means that any
code trying to use them (typically: regs->sp) needs to jump through
some unfortunate hoops.

Change the entry code to fix this up and create a full pt_regs frame.

This then simplifies various trampolines in ftrace and kprobes, the
stack unwinder, ptrace, kdump and kgdb.

Much thanks to Josh for help with the cleanups!

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Josh Poimboeuf <jpoimboe@redhat.com>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-06-25 10:23:47 +02:00

213 lines
6.0 KiB
C

/* 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 <linux/kernel.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 - 1) /* 640K */
/*
* 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));
} 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 = _THIS_IP_;
}
}
#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 */