The name comes from the similarity to the exec system call.
+config CRASH_DUMP
+ bool "Build kdump crash kernel"
+ help
+ Generate crash dump after being started by kexec. This should
+ be normally only set in special crash dump kernels which are
+ loaded in the main kernel with kexec-tools into a specially
+ reserved region and then later executed after a crash by
+ kdump/kexec.
+
+ For more details see Documentation/admin-guide/kdump/kdump.rst
+
+config PHYSICAL_START
+ hex "Physical address where the kernel is loaded"
+ default "0x90000000a0000000"
+ depends on CRASH_DUMP
+ help
+ This gives the XKPRANGE address where the kernel is loaded.
+ If you plan to use kernel for capturing the crash dump change
+ this value to start of the reserved region (the "X" value as
+ specified in the "crashkernel=YM@XM" command line boot parameter
+ passed to the panic-ed kernel).
+
config SECCOMP
bool "Enable seccomp to safely compute untrusted bytecode"
depends on PROC_FS
cflags-y += -ffreestanding
cflags-y += $(call cc-option, -mno-check-zero-division)
+ifndef CONFIG_PHYSICAL_START
load-y = 0x9000000000200000
+else
+load-y = $(CONFIG_PHYSICAL_START)
+endif
bootvars-y = VMLINUX_LOAD_ADDRESS=$(load-y)
drivers-$(CONFIG_PCI) += arch/loongarch/pci/
obj-$(CONFIG_MAGIC_SYSRQ) += sysrq.o
obj-$(CONFIG_KEXEC) += machine_kexec.o relocate_kernel.o
+obj-$(CONFIG_CRASH_DUMP) += crash_dump.o
obj-$(CONFIG_UNWINDER_GUESS) += unwind_guess.o
obj-$(CONFIG_UNWINDER_PROLOGUE) += unwind_prologue.o
--- /dev/null
+// SPDX-License-Identifier: GPL-2.0
+#include <linux/crash_dump.h>
+#include <linux/io.h>
+#include <linux/uio.h>
+
+ssize_t copy_oldmem_page(struct iov_iter *iter, unsigned long pfn,
+ size_t csize, unsigned long offset)
+{
+ void *vaddr;
+
+ if (!csize)
+ return 0;
+
+ vaddr = memremap(__pfn_to_phys(pfn), PAGE_SIZE, MEMREMAP_WB);
+ if (!vaddr)
+ return -ENOMEM;
+
+ csize = copy_to_iter(vaddr + offset, csize, iter);
+
+ memunmap(vaddr);
+
+ return csize;
+}
#include <linux/compiler.h>
#include <linux/cpu.h>
#include <linux/kexec.h>
-#include <linux/mm.h>
+#include <linux/crash_dump.h>
#include <linux/delay.h>
+#include <linux/irq.h>
#include <linux/libfdt.h>
+#include <linux/mm.h>
#include <linux/of_fdt.h>
+#include <linux/reboot.h>
+#include <linux/sched.h>
+#include <linux/sched/task_stack.h>
#include <asm/bootinfo.h>
#include <asm/cacheflush.h>
#define KEXEC_CMDLINE_ADDR TO_CACHE(0x108000UL)
static unsigned long reboot_code_buffer;
+static cpumask_t cpus_in_crash = CPU_MASK_NONE;
#ifdef CONFIG_SMP
static void (*relocated_kexec_smp_wait)(void *);
return -EINVAL;
}
- /* kexec need a safe page to save reboot_code_buffer */
+ /* kexec/kdump need a safe page to save reboot_code_buffer */
kimage->control_code_page = virt_to_page((void *)KEXEC_CONTROL_CODE);
reboot_code_buffer = (unsigned long)page_address(kimage->control_code_page);
/*
* We know we were online, and there will be no incoming IPIs at
- * this point.
+ * this point. Mark online again before rebooting so that the crash
+ * analysis tool will see us correctly.
*/
set_cpu_online(smp_processor_id(), true);
kexec_reboot();
}
-#endif
+
+static void crash_shutdown_secondary(void *passed_regs)
+{
+ int cpu = smp_processor_id();
+ struct pt_regs *regs = passed_regs;
+
+ /*
+ * If we are passed registers, use those. Otherwise get the
+ * regs from the last interrupt, which should be correct, as
+ * we are in an interrupt. But if the regs are not there,
+ * pull them from the top of the stack. They are probably
+ * wrong, but we need something to keep from crashing again.
+ */
+ if (!regs)
+ regs = get_irq_regs();
+ if (!regs)
+ regs = task_pt_regs(current);
+
+ if (!cpu_online(cpu))
+ return;
+
+ /* We won't be sent IPIs any more. */
+ set_cpu_online(cpu, false);
+
+ local_irq_disable();
+ if (!cpumask_test_cpu(cpu, &cpus_in_crash))
+ crash_save_cpu(regs, cpu);
+ cpumask_set_cpu(cpu, &cpus_in_crash);
+
+ while (!atomic_read(&kexec_ready_to_reboot))
+ cpu_relax();
+
+ kexec_reboot();
+}
+
+void crash_smp_send_stop(void)
+{
+ unsigned int ncpus;
+ unsigned long timeout;
+ static int cpus_stopped;
+
+ /*
+ * This function can be called twice in panic path, but obviously
+ * we should execute this only once.
+ */
+ if (cpus_stopped)
+ return;
+
+ cpus_stopped = 1;
+
+ /* Excluding the panic cpu */
+ ncpus = num_online_cpus() - 1;
+
+ smp_call_function(crash_shutdown_secondary, NULL, 0);
+ smp_wmb();
+
+ /*
+ * The crash CPU sends an IPI and wait for other CPUs to
+ * respond. Delay of at least 10 seconds.
+ */
+ timeout = MSEC_PER_SEC * 10;
+ pr_emerg("Sending IPI to other cpus...\n");
+ while ((cpumask_weight(&cpus_in_crash) < ncpus) && timeout--) {
+ mdelay(1);
+ cpu_relax();
+ }
+}
+#endif /* defined(CONFIG_SMP) */
void machine_shutdown(void)
{
void machine_crash_shutdown(struct pt_regs *regs)
{
+ int crashing_cpu;
+
+ local_irq_disable();
+
+ crashing_cpu = smp_processor_id();
+ crash_save_cpu(regs, crashing_cpu);
+
+#ifdef CONFIG_SMP
+ crash_smp_send_stop();
+#endif
+ cpumask_set_cpu(crashing_cpu, &cpus_in_crash);
+
+ pr_info("Starting crashdump kernel...\n");
}
void machine_kexec(struct kimage *image)
start_addr = (unsigned long)phys_to_virt(image->start);
- first_ind_entry = (unsigned long)phys_to_virt(image->head & PAGE_MASK);
+ first_ind_entry = (image->type == KEXEC_TYPE_DEFAULT) ?
+ (unsigned long)phys_to_virt(image->head & PAGE_MASK) : 0;
/*
* The generic kexec code builds a page list with physical
/* Reserve the kernel text/data/bss */
memblock_reserve(__pa_symbol(&_text),
__pa_symbol(&_end) - __pa_symbol(&_text));
-
- /* Reserve the initrd */
- reserve_initrd_mem();
}
*/
move s0, a4
+ /*
+ * In case of a kdump/crash kernel, the indirection page is not
+ * populated as the kernel is directly copied to a reserved location
+ */
+ beqz s0, done
+
process_entry:
PTR_L s1, s0, 0
PTR_ADDI s0, s0, SZREG
#include <linux/memblock.h>
#include <linux/initrd.h>
#include <linux/ioport.h>
+#include <linux/kexec.h>
+#include <linux/crash_dump.h>
#include <linux/root_dev.h>
#include <linux/console.h>
#include <linux/pfn.h>
}
early_param("mem", early_parse_mem);
+static void __init arch_reserve_vmcore(void)
+{
+#ifdef CONFIG_PROC_VMCORE
+ u64 i;
+ phys_addr_t start, end;
+
+ if (!is_kdump_kernel())
+ return;
+
+ if (!elfcorehdr_size) {
+ for_each_mem_range(i, &start, &end) {
+ if (elfcorehdr_addr >= start && elfcorehdr_addr < end) {
+ /*
+ * Reserve from the elf core header to the end of
+ * the memory segment, that should all be kdump
+ * reserved memory.
+ */
+ elfcorehdr_size = end - elfcorehdr_addr;
+ break;
+ }
+ }
+ }
+
+ if (memblock_is_region_reserved(elfcorehdr_addr, elfcorehdr_size)) {
+ pr_warn("elfcorehdr is overlapped\n");
+ return;
+ }
+
+ memblock_reserve(elfcorehdr_addr, elfcorehdr_size);
+
+ pr_info("Reserving %llu KiB of memory at 0x%llx for elfcorehdr\n",
+ elfcorehdr_size >> 10, elfcorehdr_addr);
+#endif
+}
+
+static void __init arch_parse_crashkernel(void)
+{
+#ifdef CONFIG_KEXEC
+ int ret;
+ unsigned long long start;
+ unsigned long long total_mem;
+ unsigned long long crash_base, crash_size;
+
+ total_mem = memblock_phys_mem_size();
+ ret = parse_crashkernel(boot_command_line, total_mem, &crash_size, &crash_base);
+ if (ret < 0 || crash_size <= 0)
+ return;
+
+ start = memblock_phys_alloc_range(crash_size, 1, crash_base, crash_base + crash_size);
+ if (start != crash_base) {
+ pr_warn("Invalid memory region reserved for crash kernel\n");
+ return;
+ }
+
+ crashk_res.start = crash_base;
+ crashk_res.end = crash_base + crash_size - 1;
+#endif
+}
+
void __init platform_init(void)
{
+ arch_reserve_vmcore();
+ arch_parse_crashkernel();
+
#ifdef CONFIG_ACPI_TABLE_UPGRADE
acpi_table_upgrade();
#endif
request_resource(res, &data_resource);
request_resource(res, &bss_resource);
}
+
+#ifdef CONFIG_KEXEC
+ if (crashk_res.start < crashk_res.end) {
+ insert_resource(&iomem_resource, &crashk_res);
+ pr_info("Reserving %ldMB of memory at %ldMB for crashkernel\n",
+ (unsigned long)((crashk_res.end - crashk_res.start + 1) >> 20),
+ (unsigned long)(crashk_res.start >> 20));
+ }
+#endif
}
static int __init reserve_memblock_reserved_regions(void)
memblock_init();
pagetable_init();
parse_early_param();
+ reserve_initrd_mem();
platform_init();
arch_mem_init(cmdline_p);
#include <linux/entry-common.h>
#include <linux/init.h>
#include <linux/kernel.h>
+#include <linux/kexec.h>
#include <linux/module.h>
#include <linux/extable.h>
#include <linux/mm.h>
oops_exit();
+ if (regs && kexec_should_crash(current))
+ crash_kexec(regs);
+
if (in_interrupt())
panic("Fatal exception in interrupt");
projects / kernel.git / commitdiff