android_kernel_xiaomi_sm8350/arch/ia64/kernel/machine_kexec.c
Hidetoshi Seto 07a6a4ae82 [IA64] kexec: Make INIT safe while transition to
kdump/kexec kernel

Summary:

  Asserting INIT on the beginning of kdump/kexec kernel will result
  in unexpected behavior because INIT handler for previous kernel is
  invoked on new kernel.

Description:

  In panic situation, we can receive INIT while kernel transition,
  i.e. from beginning of panic to bootstrap of kdump kernel.
  Since we initialize registers on leave from current kernel, no
  longer monarch/slave handlers of current kernel in virtual mode are
  called safely.  (In fact system goes hang as far as I confirmed)

How to Reproduce:

  Start kdump
    # echo c > /proc/sysrq-trigger
  Then assert INIT while kdump kernel is booting, before new INIT
  handler for kdump kernel is registered.

Expected(Desirable) result:

  kdump kernel boots without any problem, crashdump retrieved

Actual result:

  INIT handler for previous kernel is invoked on kdump kernel
  => panic, hang etc. (unexpected)

Proposed fix:

  We can unregister these init handlers from SAL before jumping into
  new kernel, however then the INIT will fallback to default behavior,
  result in warmboot by SAL (according to the SAL specification) and
  we cannot retrieve the crashdump.

  Therefore this patch introduces a NOP init handler and register it
  to SAL before leave from current kernel, to start kdump safely by
  preventing INITs from entering virtual mode and resulting in warmboot.

  On the other hand, in case of kexec that not for kdump, it also
  has same problem with INIT while kernel transition.
  This patch handles this case differently, because for kexec
  unregistering handlers will be preferred than registering NOP
  handler, since the situation "no handlers registered" is usual
  state for kernel's entry.

Signed-off-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Haren Myneni <hbabu@us.ibm.com>
Cc: kexec@lists.infradead.org
Acked-by: Fenghua Yu <fenghua.yu@intel.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
2009-09-14 16:18:02 -07:00

167 lines
4.4 KiB
C

/*
* arch/ia64/kernel/machine_kexec.c
*
* Handle transition of Linux booting another kernel
* Copyright (C) 2005 Hewlett-Packard Development Comapny, L.P.
* Copyright (C) 2005 Khalid Aziz <khalid.aziz@hp.com>
* Copyright (C) 2006 Intel Corp, Zou Nan hai <nanhai.zou@intel.com>
*
* This source code is licensed under the GNU General Public License,
* Version 2. See the file COPYING for more details.
*/
#include <linux/mm.h>
#include <linux/kexec.h>
#include <linux/cpu.h>
#include <linux/irq.h>
#include <linux/efi.h>
#include <linux/numa.h>
#include <linux/mmzone.h>
#include <asm/numa.h>
#include <asm/mmu_context.h>
#include <asm/setup.h>
#include <asm/delay.h>
#include <asm/meminit.h>
#include <asm/processor.h>
#include <asm/sal.h>
#include <asm/mca.h>
typedef NORET_TYPE void (*relocate_new_kernel_t)(
unsigned long indirection_page,
unsigned long start_address,
struct ia64_boot_param *boot_param,
unsigned long pal_addr) ATTRIB_NORET;
struct kimage *ia64_kimage;
struct resource efi_memmap_res = {
.name = "EFI Memory Map",
.start = 0,
.end = 0,
.flags = IORESOURCE_BUSY | IORESOURCE_MEM
};
struct resource boot_param_res = {
.name = "Boot parameter",
.start = 0,
.end = 0,
.flags = IORESOURCE_BUSY | IORESOURCE_MEM
};
/*
* Do what every setup is needed on image and the
* reboot code buffer to allow us to avoid allocations
* later.
*/
int machine_kexec_prepare(struct kimage *image)
{
void *control_code_buffer;
const unsigned long *func;
func = (unsigned long *)&relocate_new_kernel;
/* Pre-load control code buffer to minimize work in kexec path */
control_code_buffer = page_address(image->control_code_page);
memcpy((void *)control_code_buffer, (const void *)func[0],
relocate_new_kernel_size);
flush_icache_range((unsigned long)control_code_buffer,
(unsigned long)control_code_buffer + relocate_new_kernel_size);
ia64_kimage = image;
return 0;
}
void machine_kexec_cleanup(struct kimage *image)
{
}
/*
* Do not allocate memory (or fail in any way) in machine_kexec().
* We are past the point of no return, committed to rebooting now.
*/
static void ia64_machine_kexec(struct unw_frame_info *info, void *arg)
{
struct kimage *image = arg;
relocate_new_kernel_t rnk;
void *pal_addr = efi_get_pal_addr();
unsigned long code_addr = (unsigned long)page_address(image->control_code_page);
int ii;
u64 fp, gp;
ia64_fptr_t *init_handler = (ia64_fptr_t *)ia64_os_init_on_kdump;
BUG_ON(!image);
if (image->type == KEXEC_TYPE_CRASH) {
crash_save_this_cpu();
current->thread.ksp = (__u64)info->sw - 16;
/* Register noop init handler */
fp = ia64_tpa(init_handler->fp);
gp = ia64_tpa(ia64_getreg(_IA64_REG_GP));
ia64_sal_set_vectors(SAL_VECTOR_OS_INIT, fp, gp, 0, fp, gp, 0);
} else {
/* Unregister init handlers of current kernel */
ia64_sal_set_vectors(SAL_VECTOR_OS_INIT, 0, 0, 0, 0, 0, 0);
}
/* Interrupts aren't acceptable while we reboot */
local_irq_disable();
/* Mask CMC and Performance Monitor interrupts */
ia64_setreg(_IA64_REG_CR_PMV, 1 << 16);
ia64_setreg(_IA64_REG_CR_CMCV, 1 << 16);
/* Mask ITV and Local Redirect Registers */
ia64_set_itv(1 << 16);
ia64_set_lrr0(1 << 16);
ia64_set_lrr1(1 << 16);
/* terminate possible nested in-service interrupts */
for (ii = 0; ii < 16; ii++)
ia64_eoi();
/* unmask TPR and clear any pending interrupts */
ia64_setreg(_IA64_REG_CR_TPR, 0);
ia64_srlz_d();
while (ia64_get_ivr() != IA64_SPURIOUS_INT_VECTOR)
ia64_eoi();
platform_kernel_launch_event();
rnk = (relocate_new_kernel_t)&code_addr;
(*rnk)(image->head, image->start, ia64_boot_param,
GRANULEROUNDDOWN((unsigned long) pal_addr));
BUG();
}
void machine_kexec(struct kimage *image)
{
BUG_ON(!image);
unw_init_running(ia64_machine_kexec, image);
for(;;);
}
void arch_crash_save_vmcoreinfo(void)
{
#if defined(CONFIG_DISCONTIGMEM) || defined(CONFIG_SPARSEMEM)
VMCOREINFO_SYMBOL(pgdat_list);
VMCOREINFO_LENGTH(pgdat_list, MAX_NUMNODES);
#endif
#ifdef CONFIG_NUMA
VMCOREINFO_SYMBOL(node_memblk);
VMCOREINFO_LENGTH(node_memblk, NR_NODE_MEMBLKS);
VMCOREINFO_STRUCT_SIZE(node_memblk_s);
VMCOREINFO_OFFSET(node_memblk_s, start_paddr);
VMCOREINFO_OFFSET(node_memblk_s, size);
#endif
#ifdef CONFIG_PGTABLE_3
VMCOREINFO_CONFIG(PGTABLE_3);
#elif CONFIG_PGTABLE_4
VMCOREINFO_CONFIG(PGTABLE_4);
#endif
}
unsigned long paddr_vmcoreinfo_note(void)
{
return ia64_tpa((unsigned long)(char *)&vmcoreinfo_note);
}