ec9ce0dbaa
- Saving the cpu registers of all cpus before booting in to the crash kernel. - crash_setup_regs will save the registers of the cpu on which panic has occured. One of the concerns ppc64 folks raised is that after capturing the register states, one should not pop the current call frame and push new one. Hence it has been inlined. More call frames later get pushed on to stack (machine_crash_shutdown() and machine_kexec()), but one will not want to backtrace those. - Not very sure about the CFI annotations. With this patch I am getting decent backtrace with gdb. Assuming, compiler has generated enough debugging information for crash_kexec(). Coding crash_setup_regs() in pure assembly makes it tricky because then it can not be inlined and we don't want to return back after capturing register states we don't want to pop this call frame. - Saving the non-panicing cpus registers will be done in the NMI handler while shooting down them in machine_crash_shutdown. - Introducing CRASH_DUMP option in Kconfig for x86_64. Signed-off-by: Murali M Chakravarthy <muralim@in.ibm.com> Signed-off-by: Vivek Goyal <vgoyal@in.ibm.com> Cc: Andi Kleen <ak@muc.de> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
66 lines
2.5 KiB
C
66 lines
2.5 KiB
C
#ifndef _X86_64_KEXEC_H
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#define _X86_64_KEXEC_H
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#include <asm/page.h>
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#include <asm/proto.h>
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#include <asm/ptrace.h>
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/*
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* KEXEC_SOURCE_MEMORY_LIMIT maximum page get_free_page can return.
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* I.e. Maximum page that is mapped directly into kernel memory,
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* and kmap is not required.
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*
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* So far x86_64 is limited to 40 physical address bits.
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*/
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/* Maximum physical address we can use pages from */
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#define KEXEC_SOURCE_MEMORY_LIMIT (0xFFFFFFFFFFUL)
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/* Maximum address we can reach in physical address mode */
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#define KEXEC_DESTINATION_MEMORY_LIMIT (0xFFFFFFFFFFUL)
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/* Maximum address we can use for the control pages */
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#define KEXEC_CONTROL_MEMORY_LIMIT (0xFFFFFFFFFFUL)
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/* Allocate one page for the pdp and the second for the code */
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#define KEXEC_CONTROL_CODE_SIZE (4096UL + 4096UL)
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/* The native architecture */
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#define KEXEC_ARCH KEXEC_ARCH_X86_64
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#define MAX_NOTE_BYTES 1024
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/*
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* Saving the registers of the cpu on which panic occured in
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* crash_kexec to save a valid sp. The registers of other cpus
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* will be saved in machine_crash_shutdown while shooting down them.
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*/
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static inline void crash_setup_regs(struct pt_regs *newregs,
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struct pt_regs *oldregs)
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{
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if (oldregs)
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memcpy(newregs, oldregs, sizeof(*newregs));
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else {
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__asm__ __volatile__("movq %%rbx,%0" : "=m"(newregs->rbx));
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__asm__ __volatile__("movq %%rcx,%0" : "=m"(newregs->rcx));
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__asm__ __volatile__("movq %%rdx,%0" : "=m"(newregs->rdx));
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__asm__ __volatile__("movq %%rsi,%0" : "=m"(newregs->rsi));
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__asm__ __volatile__("movq %%rdi,%0" : "=m"(newregs->rdi));
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__asm__ __volatile__("movq %%rbp,%0" : "=m"(newregs->rbp));
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__asm__ __volatile__("movq %%rax,%0" : "=m"(newregs->rax));
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__asm__ __volatile__("movq %%rsp,%0" : "=m"(newregs->rsp));
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__asm__ __volatile__("movq %%r8,%0" : "=m"(newregs->r8));
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__asm__ __volatile__("movq %%r9,%0" : "=m"(newregs->r9));
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__asm__ __volatile__("movq %%r10,%0" : "=m"(newregs->r10));
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__asm__ __volatile__("movq %%r11,%0" : "=m"(newregs->r11));
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__asm__ __volatile__("movq %%r12,%0" : "=m"(newregs->r12));
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__asm__ __volatile__("movq %%r13,%0" : "=m"(newregs->r13));
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__asm__ __volatile__("movq %%r14,%0" : "=m"(newregs->r14));
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__asm__ __volatile__("movq %%r15,%0" : "=m"(newregs->r15));
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__asm__ __volatile__("movl %%ss, %%eax;" :"=a"(newregs->ss));
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__asm__ __volatile__("movl %%cs, %%eax;" :"=a"(newregs->cs));
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__asm__ __volatile__("pushfq; popq %0" :"=m"(newregs->eflags));
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newregs->rip = (unsigned long)current_text_addr();
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}
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}
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#endif /* _X86_64_KEXEC_H */
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