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[PATCH] Kexec / Kdump: Unify elf note code

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The elf note saving code is currently duplicated over several
architectures.  This cleanup patch simply adds code to a common file and
then replaces the arch-specific code with calls to the newly added code.

The only drawback with this approach is that s390 doesn't fully support
kexec-on-panic which for that arch leads to introduction of unused code.

Signed-off-by: Magnus Damm <magnus@valinux.co.jp>
Cc: Vivek Goyal <vgoyal@in.ibm.com>
Cc: Andi Kleen <ak@suse.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This commit is contained in:
Magnus Damm 2006-12-06 20:40:41 -08:00 committed by Linus Torvalds
parent 6d4df677f8
commit 85916f8166
5 changed files with 63 additions and 188 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

66
arch/i386/kernel/crash.c
View file

@ -31,68 +31,6 @@
/* This keeps a track of which one is crashing cpu. */
static int crashing_cpu;
static u32 *append_elf_note(u32 *buf, char *name, unsigned type, void *data,
size_t data_len)
{
struct elf_note note;
note.n_namesz = strlen(name) + 1;
note.n_descsz = data_len;
note.n_type = type;
memcpy(buf, &note, sizeof(note));
buf += (sizeof(note) +3)/4;
memcpy(buf, name, note.n_namesz);
buf += (note.n_namesz + 3)/4;
memcpy(buf, data, note.n_descsz);
buf += (note.n_descsz + 3)/4;
return buf;
}
static void final_note(u32 *buf)
{
struct elf_note note;
note.n_namesz = 0;
note.n_descsz = 0;
note.n_type = 0;
memcpy(buf, &note, sizeof(note));
}
static void crash_save_this_cpu(struct pt_regs *regs, int cpu)
{
struct elf_prstatus prstatus;
u32 *buf;
if ((cpu < 0) || (cpu >= NR_CPUS))
return;
/* Using ELF notes here is opportunistic.
* I need a well defined structure format
* for the data I pass, and I need tags
* on the data to indicate what information I have
* squirrelled away. ELF notes happen to provide
* all of that, so there is no need to invent something new.
*/
buf = (u32*)per_cpu_ptr(crash_notes, cpu);
if (!buf)
return;
memset(&prstatus, 0, sizeof(prstatus));
prstatus.pr_pid = current->pid;
elf_core_copy_regs(&prstatus.pr_reg, regs);
buf = append_elf_note(buf, "CORE", NT_PRSTATUS, &prstatus,
sizeof(prstatus));
final_note(buf);
}
static void crash_save_self(struct pt_regs *regs)
{
int cpu;
cpu = safe_smp_processor_id();
crash_save_this_cpu(regs, cpu);
}
#if defined(CONFIG_SMP) && defined(CONFIG_X86_LOCAL_APIC)
static atomic_t waiting_for_crash_ipi;
@ -121,7 +59,7 @@ static int crash_nmi_callback(struct notifier_block *self,
crash_fixup_ss_esp(&fixed_regs, regs);
regs = &fixed_regs;
}
crash_save_this_cpu(regs, cpu);
crash_save_cpu(regs, cpu);
disable_local_APIC();
atomic_dec(&waiting_for_crash_ipi);
/* Assume hlt works */
@ -195,5 +133,5 @@ void machine_crash_shutdown(struct pt_regs *regs)
#if defined(CONFIG_X86_IO_APIC)
disable_IO_APIC();
#endif
crash_save_self(regs);
crash_save_cpu(regs, safe_smp_processor_id());
}

59
arch/powerpc/kernel/crash.c
View file

@ -46,61 +46,6 @@ int crashing_cpu = -1;
static cpumask_t cpus_in_crash = CPU_MASK_NONE;
cpumask_t cpus_in_sr = CPU_MASK_NONE;
static u32 *append_elf_note(u32 *buf, char *name, unsigned type, void *data,
size_t data_len)
{
struct elf_note note;
note.n_namesz = strlen(name) + 1;
note.n_descsz = data_len;
note.n_type = type;
memcpy(buf, &note, sizeof(note));
buf += (sizeof(note) +3)/4;
memcpy(buf, name, note.n_namesz);
buf += (note.n_namesz + 3)/4;
memcpy(buf, data, note.n_descsz);
buf += (note.n_descsz + 3)/4;
return buf;
}
static void final_note(u32 *buf)
{
struct elf_note note;
note.n_namesz = 0;
note.n_descsz = 0;
note.n_type = 0;
memcpy(buf, &note, sizeof(note));
}
static void crash_save_this_cpu(struct pt_regs *regs, int cpu)
{
struct elf_prstatus prstatus;
u32 *buf;
if ((cpu < 0) || (cpu >= NR_CPUS))
return;
/* Using ELF notes here is opportunistic.
* I need a well defined structure format
* for the data I pass, and I need tags
* on the data to indicate what information I have
* squirrelled away. ELF notes happen to provide
* all of that that no need to invent something new.
*/
buf = (u32*)per_cpu_ptr(crash_notes, cpu);
if (!buf)
return;
memset(&prstatus, 0, sizeof(prstatus));
prstatus.pr_pid = current->pid;
elf_core_copy_regs(&prstatus.pr_reg, regs);
buf = append_elf_note(buf, "CORE", NT_PRSTATUS, &prstatus,
sizeof(prstatus));
final_note(buf);
}
#ifdef CONFIG_SMP
static atomic_t enter_on_soft_reset = ATOMIC_INIT(0);
@ -113,7 +58,7 @@ void crash_ipi_callback(struct pt_regs *regs)
hard_irq_disable();
if (!cpu_isset(cpu, cpus_in_crash))
crash_save_this_cpu(regs, cpu);
crash_save_cpu(regs, cpu);
cpu_set(cpu, cpus_in_crash);
/*
@ -306,7 +251,7 @@ void default_machine_crash_shutdown(struct pt_regs *regs)
* such that another IPI will not be sent.
*/
crashing_cpu = smp_processor_id();
crash_save_this_cpu(regs, crashing_cpu);
crash_save_cpu(regs, crashing_cpu);
crash_kexec_prepare_cpus(crashing_cpu);
cpu_set(crashing_cpu, cpus_in_crash);
if (ppc_md.kexec_cpu_down)

69
arch/x86_64/kernel/crash.c
View file

@ -28,71 +28,6 @@
/* This keeps a track of which one is crashing cpu. */
static int crashing_cpu;
static u32 *append_elf_note(u32 *buf, char *name, unsigned type,
void *data, size_t data_len)
{
struct elf_note note;
note.n_namesz = strlen(name) + 1;
note.n_descsz = data_len;
note.n_type = type;
memcpy(buf, &note, sizeof(note));
buf += (sizeof(note) +3)/4;
memcpy(buf, name, note.n_namesz);
buf += (note.n_namesz + 3)/4;
memcpy(buf, data, note.n_descsz);
buf += (note.n_descsz + 3)/4;
return buf;
}
static void final_note(u32 *buf)
{
struct elf_note note;
note.n_namesz = 0;
note.n_descsz = 0;
note.n_type = 0;
memcpy(buf, &note, sizeof(note));
}
static void crash_save_this_cpu(struct pt_regs *regs, int cpu)
{
struct elf_prstatus prstatus;
u32 *buf;
if ((cpu < 0) || (cpu >= NR_CPUS))
return;
/* Using ELF notes here is opportunistic.
* I need a well defined structure format
* for the data I pass, and I need tags
* on the data to indicate what information I have
* squirrelled away. ELF notes happen to provide
* all of that, no need to invent something new.
*/
buf = (u32*)per_cpu_ptr(crash_notes, cpu);
if (!buf)
return;
memset(&prstatus, 0, sizeof(prstatus));
prstatus.pr_pid = current->pid;
elf_core_copy_regs(&prstatus.pr_reg, regs);
buf = append_elf_note(buf, "CORE", NT_PRSTATUS, &prstatus,
sizeof(prstatus));
final_note(buf);
}
static void crash_save_self(struct pt_regs *regs)
{
int cpu;
cpu = smp_processor_id();
crash_save_this_cpu(regs, cpu);
}
#ifdef CONFIG_SMP
static atomic_t waiting_for_crash_ipi;
@ -117,7 +52,7 @@ static int crash_nmi_callback(struct notifier_block *self,
return NOTIFY_STOP;
local_irq_disable();
crash_save_this_cpu(regs, cpu);
crash_save_cpu(regs, cpu);
disable_local_APIC();
atomic_dec(&waiting_for_crash_ipi);
/* Assume hlt works */
@ -196,5 +131,5 @@ void machine_crash_shutdown(struct pt_regs *regs)
disable_IO_APIC();
crash_save_self(regs);
crash_save_cpu(regs, smp_processor_id());
}

1
include/linux/kexec.h
View file

@ -105,6 +105,7 @@ extern struct page *kimage_alloc_control_pages(struct kimage *image,
unsigned int order);
extern void crash_kexec(struct pt_regs *);
int kexec_should_crash(struct task_struct *);
void crash_save_cpu(struct pt_regs *regs, int cpu);
extern struct kimage *kexec_image;
extern struct kimage *kexec_crash_image;

56
kernel/kexec.c
View file

@ -20,6 +20,8 @@
#include <linux/syscalls.h>
#include <linux/ioport.h>
#include <linux/hardirq.h>
#include <linux/elf.h>
#include <linux/elfcore.h>
#include <asm/page.h>
#include <asm/uaccess.h>
@ -1066,6 +1068,60 @@ void crash_kexec(struct pt_regs *regs)
}
}
static u32 *append_elf_note(u32 *buf, char *name, unsigned type, void *data,
size_t data_len)
{
struct elf_note note;
note.n_namesz = strlen(name) + 1;
note.n_descsz = data_len;
note.n_type = type;
memcpy(buf, &note, sizeof(note));
buf += (sizeof(note) + 3)/4;
memcpy(buf, name, note.n_namesz);
buf += (note.n_namesz + 3)/4;
memcpy(buf, data, note.n_descsz);
buf += (note.n_descsz + 3)/4;
return buf;
}
static void final_note(u32 *buf)
{
struct elf_note note;
note.n_namesz = 0;
note.n_descsz = 0;
note.n_type = 0;
memcpy(buf, &note, sizeof(note));
}
void crash_save_cpu(struct pt_regs *regs, int cpu)
{
struct elf_prstatus prstatus;
u32 *buf;
if ((cpu < 0) || (cpu >= NR_CPUS))
return;
/* Using ELF notes here is opportunistic.
* I need a well defined structure format
* for the data I pass, and I need tags
* on the data to indicate what information I have
* squirrelled away. ELF notes happen to provide
* all of that, so there is no need to invent something new.
*/
buf = (u32*)per_cpu_ptr(crash_notes, cpu);
if (!buf)
return;
memset(&prstatus, 0, sizeof(prstatus));
prstatus.pr_pid = current->pid;
elf_core_copy_regs(&prstatus.pr_reg, regs);
buf = append_elf_note(buf, "CORE", NT_PRSTATUS, &prstatus,
sizeof(prstatus));
final_note(buf);
}
static int __init crash_notes_memory_init(void)
{
/* Allocate memory for saving cpu registers. */