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Diffstat (limited to 'arch/x86/kernel/crash.c')
-rw-r--r--arch/x86/kernel/crash.c128
1 files changed, 36 insertions, 92 deletions
diff --git a/arch/x86/kernel/crash.c b/arch/x86/kernel/crash.c
index eb651fbde92a..00fc55ac7ffa 100644
--- a/arch/x86/kernel/crash.c
+++ b/arch/x86/kernel/crash.c
@@ -24,6 +24,7 @@
#include <linux/export.h>
#include <linux/slab.h>
#include <linux/vmalloc.h>
+#include <linux/memblock.h>
#include <asm/processor.h>
#include <asm/hardirq.h>
@@ -39,6 +40,7 @@
#include <asm/virtext.h>
#include <asm/intel_pt.h>
#include <asm/crash.h>
+#include <asm/cmdline.h>
/* Used while preparing memory map entries for second kernel */
struct crash_memmap_data {
@@ -68,6 +70,19 @@ static inline void cpu_crash_vmclear_loaded_vmcss(void)
rcu_read_unlock();
}
+/*
+ * When the crashkernel option is specified, only use the low
+ * 1M for the real mode trampoline.
+ */
+void __init crash_reserve_low_1M(void)
+{
+ if (cmdline_find_option(boot_command_line, "crashkernel", NULL, 0) < 0)
+ return;
+
+ memblock_reserve(0, 1<<20);
+ pr_info("Reserving the low 1M of memory for crashkernel\n");
+}
+
#if defined(CONFIG_SMP) && defined(CONFIG_X86_LOCAL_APIC)
static void kdump_nmi_callback(int cpu, struct pt_regs *regs)
@@ -173,8 +188,6 @@ void native_machine_crash_shutdown(struct pt_regs *regs)
#ifdef CONFIG_KEXEC_FILE
-static unsigned long crash_zero_bytes;
-
static int get_nr_ram_ranges_callback(struct resource *res, void *arg)
{
unsigned int *nr_ranges = arg;
@@ -189,8 +202,7 @@ static struct crash_mem *fill_up_crash_elf_data(void)
unsigned int nr_ranges = 0;
struct crash_mem *cmem;
- walk_system_ram_res(0, -1, &nr_ranges,
- get_nr_ram_ranges_callback);
+ walk_system_ram_res(0, -1, &nr_ranges, get_nr_ram_ranges_callback);
if (!nr_ranges)
return NULL;
@@ -217,15 +229,19 @@ static int elf_header_exclude_ranges(struct crash_mem *cmem)
{
int ret = 0;
+ /* Exclude the low 1M because it is always reserved */
+ ret = crash_exclude_mem_range(cmem, 0, 1<<20);
+ if (ret)
+ return ret;
+
/* Exclude crashkernel region */
ret = crash_exclude_mem_range(cmem, crashk_res.start, crashk_res.end);
if (ret)
return ret;
- if (crashk_low_res.end) {
+ if (crashk_low_res.end)
ret = crash_exclude_mem_range(cmem, crashk_low_res.start,
- crashk_low_res.end);
- }
+ crashk_low_res.end);
return ret;
}
@@ -246,16 +262,13 @@ static int prepare_elf_headers(struct kimage *image, void **addr,
unsigned long *sz)
{
struct crash_mem *cmem;
- Elf64_Ehdr *ehdr;
- Elf64_Phdr *phdr;
- int ret, i;
+ int ret;
cmem = fill_up_crash_elf_data();
if (!cmem)
return -ENOMEM;
- ret = walk_system_ram_res(0, -1, cmem,
- prepare_elf64_ram_headers_callback);
+ ret = walk_system_ram_res(0, -1, cmem, prepare_elf64_ram_headers_callback);
if (ret)
goto out;
@@ -265,24 +278,8 @@ static int prepare_elf_headers(struct kimage *image, void **addr,
goto out;
/* By default prepare 64bit headers */
- ret = crash_prepare_elf64_headers(cmem,
- IS_ENABLED(CONFIG_X86_64), addr, sz);
- if (ret)
- goto out;
+ ret = crash_prepare_elf64_headers(cmem, IS_ENABLED(CONFIG_X86_64), addr, sz);
- /*
- * If a range matches backup region, adjust offset to backup
- * segment.
- */
- ehdr = (Elf64_Ehdr *)*addr;
- phdr = (Elf64_Phdr *)(ehdr + 1);
- for (i = 0; i < ehdr->e_phnum; phdr++, i++)
- if (phdr->p_type == PT_LOAD &&
- phdr->p_paddr == image->arch.backup_src_start &&
- phdr->p_memsz == image->arch.backup_src_sz) {
- phdr->p_offset = image->arch.backup_load_addr;
- break;
- }
out:
vfree(cmem);
return ret;
@@ -296,8 +293,7 @@ static int add_e820_entry(struct boot_params *params, struct e820_entry *entry)
if (nr_e820_entries >= E820_MAX_ENTRIES_ZEROPAGE)
return 1;
- memcpy(&params->e820_table[nr_e820_entries], entry,
- sizeof(struct e820_entry));
+ memcpy(&params->e820_table[nr_e820_entries], entry, sizeof(struct e820_entry));
params->e820_entries++;
return 0;
}
@@ -321,19 +317,11 @@ static int memmap_exclude_ranges(struct kimage *image, struct crash_mem *cmem,
unsigned long long mend)
{
unsigned long start, end;
- int ret = 0;
cmem->ranges[0].start = mstart;
cmem->ranges[0].end = mend;
cmem->nr_ranges = 1;
- /* Exclude Backup region */
- start = image->arch.backup_load_addr;
- end = start + image->arch.backup_src_sz - 1;
- ret = crash_exclude_mem_range(cmem, start, end);
- if (ret)
- return ret;
-
/* Exclude elf header region */
start = image->arch.elf_load_addr;
end = start + image->arch.elf_headers_sz - 1;
@@ -356,28 +344,28 @@ int crash_setup_memmap_entries(struct kimage *image, struct boot_params *params)
memset(&cmd, 0, sizeof(struct crash_memmap_data));
cmd.params = params;
- /* Add first 640K segment */
- ei.addr = image->arch.backup_src_start;
- ei.size = image->arch.backup_src_sz;
- ei.type = E820_TYPE_RAM;
- add_e820_entry(params, &ei);
+ /* Add the low 1M */
+ cmd.type = E820_TYPE_RAM;
+ flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;
+ walk_iomem_res_desc(IORES_DESC_NONE, flags, 0, (1<<20)-1, &cmd,
+ memmap_entry_callback);
/* Add ACPI tables */
cmd.type = E820_TYPE_ACPI;
flags = IORESOURCE_MEM | IORESOURCE_BUSY;
walk_iomem_res_desc(IORES_DESC_ACPI_TABLES, flags, 0, -1, &cmd,
- memmap_entry_callback);
+ memmap_entry_callback);
/* Add ACPI Non-volatile Storage */
cmd.type = E820_TYPE_NVS;
walk_iomem_res_desc(IORES_DESC_ACPI_NV_STORAGE, flags, 0, -1, &cmd,
- memmap_entry_callback);
+ memmap_entry_callback);
/* Add e820 reserved ranges */
cmd.type = E820_TYPE_RESERVED;
flags = IORESOURCE_MEM;
walk_iomem_res_desc(IORES_DESC_RESERVED, flags, 0, -1, &cmd,
- memmap_entry_callback);
+ memmap_entry_callback);
/* Add crashk_low_res region */
if (crashk_low_res.end) {
@@ -388,8 +376,7 @@ int crash_setup_memmap_entries(struct kimage *image, struct boot_params *params)
}
/* Exclude some ranges from crashk_res and add rest to memmap */
- ret = memmap_exclude_ranges(image, cmem, crashk_res.start,
- crashk_res.end);
+ ret = memmap_exclude_ranges(image, cmem, crashk_res.start, crashk_res.end);
if (ret)
goto out;
@@ -409,55 +396,12 @@ out:
return ret;
}
-static int determine_backup_region(struct resource *res, void *arg)
-{
- struct kimage *image = arg;
-
- image->arch.backup_src_start = res->start;
- image->arch.backup_src_sz = resource_size(res);
-
- /* Expecting only one range for backup region */
- return 1;
-}
-
int crash_load_segments(struct kimage *image)
{
int ret;
struct kexec_buf kbuf = { .image = image, .buf_min = 0,
.buf_max = ULONG_MAX, .top_down = false };
- /*
- * Determine and load a segment for backup area. First 640K RAM
- * region is backup source
- */
-
- ret = walk_system_ram_res(KEXEC_BACKUP_SRC_START, KEXEC_BACKUP_SRC_END,
- image, determine_backup_region);
-
- /* Zero or postive return values are ok */
- if (ret < 0)
- return ret;
-
- /* Add backup segment. */
- if (image->arch.backup_src_sz) {
- kbuf.buffer = &crash_zero_bytes;
- kbuf.bufsz = sizeof(crash_zero_bytes);
- kbuf.memsz = image->arch.backup_src_sz;
- kbuf.buf_align = PAGE_SIZE;
- /*
- * Ideally there is no source for backup segment. This is
- * copied in purgatory after crash. Just add a zero filled
- * segment for now to make sure checksum logic works fine.
- */
- ret = kexec_add_buffer(&kbuf);
- if (ret)
- return ret;
- image->arch.backup_load_addr = kbuf.mem;
- pr_debug("Loaded backup region at 0x%lx backup_start=0x%lx memsz=0x%lx\n",
- image->arch.backup_load_addr,
- image->arch.backup_src_start, kbuf.memsz);
- }
-
/* Prepare elf headers and add a segment */
ret = prepare_elf_headers(image, &kbuf.buffer, &kbuf.bufsz);
if (ret)
generated by cgit v1.2.3 (git 2.39.0) at 2024-12-03 22:19:36 +0300