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![Baoquan He](/assets/img/avatar_default.png)
Eric reported that handling corresponding crash hotplug event can be
failed easily when many memory hotplug event are notified in a short
period. They failed because failing to take __kexec_lock.
=======
[ 78.714569] Fallback order for Node 0: 0
[ 78.714575] Built 1 zonelists, mobility grouping on. Total pages: 1817886
[ 78.717133] Policy zone: Normal
[ 78.724423] crash hp: kexec_trylock() failed, elfcorehdr may be inaccurate
[ 78.727207] crash hp: kexec_trylock() failed, elfcorehdr may be inaccurate
[ 80.056643] PEFILE: Unsigned PE binary
=======
The memory hotplug events are notified very quickly and very many, while
the handling of crash hotplug is much slower relatively. So the atomic
variable __kexec_lock and kexec_trylock() can't guarantee the
serialization of crash hotplug handling.
Here, add a new mutex lock __crash_hotplug_lock to serialize crash hotplug
handling specifically. This doesn't impact the usage of __kexec_lock.
Link: https://lkml.kernel.org/r/20230926120905.392903-1-bhe@redhat.com
Fixes: 2472627561
("crash: add generic infrastructure for crash hotplug support")
Signed-off-by: Baoquan He <bhe@redhat.com>
Tested-by: Eric DeVolder <eric.devolder@oracle.com>
Reviewed-by: Eric DeVolder <eric.devolder@oracle.com>
Reviewed-by: Valentin Schneider <vschneid@redhat.com>
Cc: Sourabh Jain <sourabhjain@linux.ibm.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
923 lines
24 KiB
C
923 lines
24 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
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/*
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* crash.c - kernel crash support code.
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* Copyright (C) 2002-2004 Eric Biederman <ebiederm@xmission.com>
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*/
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#include <linux/buildid.h>
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#include <linux/crash_core.h>
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#include <linux/init.h>
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#include <linux/utsname.h>
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#include <linux/vmalloc.h>
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#include <linux/sizes.h>
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#include <linux/kexec.h>
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#include <linux/memory.h>
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#include <linux/cpuhotplug.h>
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#include <asm/page.h>
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#include <asm/sections.h>
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#include <crypto/sha1.h>
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#include "kallsyms_internal.h"
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#include "kexec_internal.h"
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/* Per cpu memory for storing cpu states in case of system crash. */
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note_buf_t __percpu *crash_notes;
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/* vmcoreinfo stuff */
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unsigned char *vmcoreinfo_data;
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size_t vmcoreinfo_size;
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u32 *vmcoreinfo_note;
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/* trusted vmcoreinfo, e.g. we can make a copy in the crash memory */
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static unsigned char *vmcoreinfo_data_safecopy;
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/*
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* parsing the "crashkernel" commandline
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*
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* this code is intended to be called from architecture specific code
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*/
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/*
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* This function parses command lines in the format
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*
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* crashkernel=ramsize-range:size[,...][@offset]
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*
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* The function returns 0 on success and -EINVAL on failure.
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*/
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static int __init parse_crashkernel_mem(char *cmdline,
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unsigned long long system_ram,
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unsigned long long *crash_size,
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unsigned long long *crash_base)
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{
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char *cur = cmdline, *tmp;
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unsigned long long total_mem = system_ram;
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/*
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* Firmware sometimes reserves some memory regions for its own use,
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* so the system memory size is less than the actual physical memory
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* size. Work around this by rounding up the total size to 128M,
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* which is enough for most test cases.
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*/
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total_mem = roundup(total_mem, SZ_128M);
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/* for each entry of the comma-separated list */
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do {
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unsigned long long start, end = ULLONG_MAX, size;
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/* get the start of the range */
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start = memparse(cur, &tmp);
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if (cur == tmp) {
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pr_warn("crashkernel: Memory value expected\n");
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return -EINVAL;
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}
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cur = tmp;
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if (*cur != '-') {
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pr_warn("crashkernel: '-' expected\n");
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return -EINVAL;
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}
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cur++;
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/* if no ':' is here, than we read the end */
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if (*cur != ':') {
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end = memparse(cur, &tmp);
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if (cur == tmp) {
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pr_warn("crashkernel: Memory value expected\n");
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return -EINVAL;
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}
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cur = tmp;
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if (end <= start) {
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pr_warn("crashkernel: end <= start\n");
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return -EINVAL;
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}
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}
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if (*cur != ':') {
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pr_warn("crashkernel: ':' expected\n");
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return -EINVAL;
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}
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cur++;
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size = memparse(cur, &tmp);
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if (cur == tmp) {
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pr_warn("Memory value expected\n");
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return -EINVAL;
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}
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cur = tmp;
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if (size >= total_mem) {
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pr_warn("crashkernel: invalid size\n");
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return -EINVAL;
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}
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/* match ? */
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if (total_mem >= start && total_mem < end) {
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*crash_size = size;
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break;
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}
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} while (*cur++ == ',');
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if (*crash_size > 0) {
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while (*cur && *cur != ' ' && *cur != '@')
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cur++;
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if (*cur == '@') {
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cur++;
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*crash_base = memparse(cur, &tmp);
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if (cur == tmp) {
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pr_warn("Memory value expected after '@'\n");
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return -EINVAL;
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}
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}
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} else
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pr_info("crashkernel size resulted in zero bytes\n");
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return 0;
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}
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/*
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* That function parses "simple" (old) crashkernel command lines like
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*
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* crashkernel=size[@offset]
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*
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* It returns 0 on success and -EINVAL on failure.
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*/
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static int __init parse_crashkernel_simple(char *cmdline,
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unsigned long long *crash_size,
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unsigned long long *crash_base)
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{
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char *cur = cmdline;
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*crash_size = memparse(cmdline, &cur);
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if (cmdline == cur) {
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pr_warn("crashkernel: memory value expected\n");
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return -EINVAL;
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}
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if (*cur == '@')
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*crash_base = memparse(cur+1, &cur);
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else if (*cur != ' ' && *cur != '\0') {
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pr_warn("crashkernel: unrecognized char: %c\n", *cur);
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return -EINVAL;
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}
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return 0;
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}
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#define SUFFIX_HIGH 0
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#define SUFFIX_LOW 1
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#define SUFFIX_NULL 2
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static __initdata char *suffix_tbl[] = {
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[SUFFIX_HIGH] = ",high",
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[SUFFIX_LOW] = ",low",
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[SUFFIX_NULL] = NULL,
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};
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/*
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* That function parses "suffix" crashkernel command lines like
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*
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* crashkernel=size,[high|low]
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*
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* It returns 0 on success and -EINVAL on failure.
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*/
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static int __init parse_crashkernel_suffix(char *cmdline,
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unsigned long long *crash_size,
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const char *suffix)
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{
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char *cur = cmdline;
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*crash_size = memparse(cmdline, &cur);
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if (cmdline == cur) {
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pr_warn("crashkernel: memory value expected\n");
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return -EINVAL;
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}
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/* check with suffix */
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if (strncmp(cur, suffix, strlen(suffix))) {
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pr_warn("crashkernel: unrecognized char: %c\n", *cur);
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return -EINVAL;
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}
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cur += strlen(suffix);
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if (*cur != ' ' && *cur != '\0') {
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pr_warn("crashkernel: unrecognized char: %c\n", *cur);
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return -EINVAL;
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}
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return 0;
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}
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static __init char *get_last_crashkernel(char *cmdline,
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const char *name,
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const char *suffix)
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{
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char *p = cmdline, *ck_cmdline = NULL;
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/* find crashkernel and use the last one if there are more */
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p = strstr(p, name);
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while (p) {
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char *end_p = strchr(p, ' ');
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char *q;
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if (!end_p)
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end_p = p + strlen(p);
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if (!suffix) {
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int i;
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/* skip the one with any known suffix */
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for (i = 0; suffix_tbl[i]; i++) {
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q = end_p - strlen(suffix_tbl[i]);
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if (!strncmp(q, suffix_tbl[i],
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strlen(suffix_tbl[i])))
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goto next;
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}
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ck_cmdline = p;
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} else {
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q = end_p - strlen(suffix);
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if (!strncmp(q, suffix, strlen(suffix)))
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ck_cmdline = p;
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}
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next:
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p = strstr(p+1, name);
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}
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return ck_cmdline;
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}
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static int __init __parse_crashkernel(char *cmdline,
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unsigned long long system_ram,
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unsigned long long *crash_size,
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unsigned long long *crash_base,
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const char *name,
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const char *suffix)
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{
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char *first_colon, *first_space;
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char *ck_cmdline;
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BUG_ON(!crash_size || !crash_base);
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*crash_size = 0;
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*crash_base = 0;
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ck_cmdline = get_last_crashkernel(cmdline, name, suffix);
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if (!ck_cmdline)
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return -ENOENT;
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ck_cmdline += strlen(name);
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if (suffix)
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return parse_crashkernel_suffix(ck_cmdline, crash_size,
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suffix);
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/*
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* if the commandline contains a ':', then that's the extended
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* syntax -- if not, it must be the classic syntax
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*/
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first_colon = strchr(ck_cmdline, ':');
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first_space = strchr(ck_cmdline, ' ');
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if (first_colon && (!first_space || first_colon < first_space))
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return parse_crashkernel_mem(ck_cmdline, system_ram,
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crash_size, crash_base);
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return parse_crashkernel_simple(ck_cmdline, crash_size, crash_base);
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}
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/*
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* That function is the entry point for command line parsing and should be
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* called from the arch-specific code.
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*/
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int __init parse_crashkernel(char *cmdline,
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unsigned long long system_ram,
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unsigned long long *crash_size,
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unsigned long long *crash_base)
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{
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return __parse_crashkernel(cmdline, system_ram, crash_size, crash_base,
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"crashkernel=", NULL);
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}
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int __init parse_crashkernel_high(char *cmdline,
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unsigned long long system_ram,
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unsigned long long *crash_size,
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unsigned long long *crash_base)
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{
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return __parse_crashkernel(cmdline, system_ram, crash_size, crash_base,
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"crashkernel=", suffix_tbl[SUFFIX_HIGH]);
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}
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int __init parse_crashkernel_low(char *cmdline,
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unsigned long long system_ram,
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unsigned long long *crash_size,
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unsigned long long *crash_base)
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{
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return __parse_crashkernel(cmdline, system_ram, crash_size, crash_base,
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"crashkernel=", suffix_tbl[SUFFIX_LOW]);
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}
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/*
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* Add a dummy early_param handler to mark crashkernel= as a known command line
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* parameter and suppress incorrect warnings in init/main.c.
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*/
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static int __init parse_crashkernel_dummy(char *arg)
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{
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return 0;
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}
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early_param("crashkernel", parse_crashkernel_dummy);
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int crash_prepare_elf64_headers(struct crash_mem *mem, int need_kernel_map,
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void **addr, unsigned long *sz)
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{
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Elf64_Ehdr *ehdr;
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Elf64_Phdr *phdr;
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unsigned long nr_cpus = num_possible_cpus(), nr_phdr, elf_sz;
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unsigned char *buf;
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unsigned int cpu, i;
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unsigned long long notes_addr;
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unsigned long mstart, mend;
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/* extra phdr for vmcoreinfo ELF note */
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nr_phdr = nr_cpus + 1;
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nr_phdr += mem->nr_ranges;
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/*
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* kexec-tools creates an extra PT_LOAD phdr for kernel text mapping
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* area (for example, ffffffff80000000 - ffffffffa0000000 on x86_64).
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* I think this is required by tools like gdb. So same physical
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* memory will be mapped in two ELF headers. One will contain kernel
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* text virtual addresses and other will have __va(physical) addresses.
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*/
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nr_phdr++;
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elf_sz = sizeof(Elf64_Ehdr) + nr_phdr * sizeof(Elf64_Phdr);
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elf_sz = ALIGN(elf_sz, ELF_CORE_HEADER_ALIGN);
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buf = vzalloc(elf_sz);
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if (!buf)
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return -ENOMEM;
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ehdr = (Elf64_Ehdr *)buf;
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phdr = (Elf64_Phdr *)(ehdr + 1);
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memcpy(ehdr->e_ident, ELFMAG, SELFMAG);
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ehdr->e_ident[EI_CLASS] = ELFCLASS64;
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ehdr->e_ident[EI_DATA] = ELFDATA2LSB;
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ehdr->e_ident[EI_VERSION] = EV_CURRENT;
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ehdr->e_ident[EI_OSABI] = ELF_OSABI;
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memset(ehdr->e_ident + EI_PAD, 0, EI_NIDENT - EI_PAD);
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ehdr->e_type = ET_CORE;
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ehdr->e_machine = ELF_ARCH;
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ehdr->e_version = EV_CURRENT;
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ehdr->e_phoff = sizeof(Elf64_Ehdr);
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ehdr->e_ehsize = sizeof(Elf64_Ehdr);
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ehdr->e_phentsize = sizeof(Elf64_Phdr);
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/* Prepare one phdr of type PT_NOTE for each possible CPU */
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for_each_possible_cpu(cpu) {
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phdr->p_type = PT_NOTE;
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notes_addr = per_cpu_ptr_to_phys(per_cpu_ptr(crash_notes, cpu));
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phdr->p_offset = phdr->p_paddr = notes_addr;
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phdr->p_filesz = phdr->p_memsz = sizeof(note_buf_t);
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(ehdr->e_phnum)++;
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phdr++;
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}
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/* Prepare one PT_NOTE header for vmcoreinfo */
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phdr->p_type = PT_NOTE;
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phdr->p_offset = phdr->p_paddr = paddr_vmcoreinfo_note();
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phdr->p_filesz = phdr->p_memsz = VMCOREINFO_NOTE_SIZE;
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(ehdr->e_phnum)++;
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phdr++;
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/* Prepare PT_LOAD type program header for kernel text region */
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if (need_kernel_map) {
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phdr->p_type = PT_LOAD;
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phdr->p_flags = PF_R|PF_W|PF_X;
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phdr->p_vaddr = (unsigned long) _text;
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phdr->p_filesz = phdr->p_memsz = _end - _text;
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phdr->p_offset = phdr->p_paddr = __pa_symbol(_text);
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ehdr->e_phnum++;
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phdr++;
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}
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/* Go through all the ranges in mem->ranges[] and prepare phdr */
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for (i = 0; i < mem->nr_ranges; i++) {
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mstart = mem->ranges[i].start;
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mend = mem->ranges[i].end;
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phdr->p_type = PT_LOAD;
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phdr->p_flags = PF_R|PF_W|PF_X;
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phdr->p_offset = mstart;
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phdr->p_paddr = mstart;
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phdr->p_vaddr = (unsigned long) __va(mstart);
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phdr->p_filesz = phdr->p_memsz = mend - mstart + 1;
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phdr->p_align = 0;
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ehdr->e_phnum++;
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pr_debug("Crash PT_LOAD ELF header. phdr=%p vaddr=0x%llx, paddr=0x%llx, sz=0x%llx e_phnum=%d p_offset=0x%llx\n",
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phdr, phdr->p_vaddr, phdr->p_paddr, phdr->p_filesz,
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ehdr->e_phnum, phdr->p_offset);
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phdr++;
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}
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*addr = buf;
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*sz = elf_sz;
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return 0;
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}
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int crash_exclude_mem_range(struct crash_mem *mem,
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unsigned long long mstart, unsigned long long mend)
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{
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int i, j;
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unsigned long long start, end, p_start, p_end;
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struct range temp_range = {0, 0};
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for (i = 0; i < mem->nr_ranges; i++) {
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start = mem->ranges[i].start;
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end = mem->ranges[i].end;
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p_start = mstart;
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p_end = mend;
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if (mstart > end || mend < start)
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continue;
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/* Truncate any area outside of range */
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if (mstart < start)
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p_start = start;
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if (mend > end)
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p_end = end;
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/* Found completely overlapping range */
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if (p_start == start && p_end == end) {
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mem->ranges[i].start = 0;
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mem->ranges[i].end = 0;
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if (i < mem->nr_ranges - 1) {
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/* Shift rest of the ranges to left */
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for (j = i; j < mem->nr_ranges - 1; j++) {
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mem->ranges[j].start =
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mem->ranges[j+1].start;
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mem->ranges[j].end =
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mem->ranges[j+1].end;
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}
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|
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/*
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* Continue to check if there are another overlapping ranges
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* from the current position because of shifting the above
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* mem ranges.
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*/
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i--;
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mem->nr_ranges--;
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continue;
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}
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mem->nr_ranges--;
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return 0;
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}
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|
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if (p_start > start && p_end < end) {
|
|
/* Split original range */
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mem->ranges[i].end = p_start - 1;
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temp_range.start = p_end + 1;
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temp_range.end = end;
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} else if (p_start != start)
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mem->ranges[i].end = p_start - 1;
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else
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mem->ranges[i].start = p_end + 1;
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break;
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}
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|
|
/* If a split happened, add the split to array */
|
|
if (!temp_range.end)
|
|
return 0;
|
|
|
|
/* Split happened */
|
|
if (i == mem->max_nr_ranges - 1)
|
|
return -ENOMEM;
|
|
|
|
/* Location where new range should go */
|
|
j = i + 1;
|
|
if (j < mem->nr_ranges) {
|
|
/* Move over all ranges one slot towards the end */
|
|
for (i = mem->nr_ranges - 1; i >= j; i--)
|
|
mem->ranges[i + 1] = mem->ranges[i];
|
|
}
|
|
|
|
mem->ranges[j].start = temp_range.start;
|
|
mem->ranges[j].end = temp_range.end;
|
|
mem->nr_ranges++;
|
|
return 0;
|
|
}
|
|
|
|
Elf_Word *append_elf_note(Elf_Word *buf, char *name, unsigned int type,
|
|
void *data, size_t data_len)
|
|
{
|
|
struct elf_note *note = (struct elf_note *)buf;
|
|
|
|
note->n_namesz = strlen(name) + 1;
|
|
note->n_descsz = data_len;
|
|
note->n_type = type;
|
|
buf += DIV_ROUND_UP(sizeof(*note), sizeof(Elf_Word));
|
|
memcpy(buf, name, note->n_namesz);
|
|
buf += DIV_ROUND_UP(note->n_namesz, sizeof(Elf_Word));
|
|
memcpy(buf, data, data_len);
|
|
buf += DIV_ROUND_UP(data_len, sizeof(Elf_Word));
|
|
|
|
return buf;
|
|
}
|
|
|
|
void final_note(Elf_Word *buf)
|
|
{
|
|
memset(buf, 0, sizeof(struct elf_note));
|
|
}
|
|
|
|
static void update_vmcoreinfo_note(void)
|
|
{
|
|
u32 *buf = vmcoreinfo_note;
|
|
|
|
if (!vmcoreinfo_size)
|
|
return;
|
|
buf = append_elf_note(buf, VMCOREINFO_NOTE_NAME, 0, vmcoreinfo_data,
|
|
vmcoreinfo_size);
|
|
final_note(buf);
|
|
}
|
|
|
|
void crash_update_vmcoreinfo_safecopy(void *ptr)
|
|
{
|
|
if (ptr)
|
|
memcpy(ptr, vmcoreinfo_data, vmcoreinfo_size);
|
|
|
|
vmcoreinfo_data_safecopy = ptr;
|
|
}
|
|
|
|
void crash_save_vmcoreinfo(void)
|
|
{
|
|
if (!vmcoreinfo_note)
|
|
return;
|
|
|
|
/* Use the safe copy to generate vmcoreinfo note if have */
|
|
if (vmcoreinfo_data_safecopy)
|
|
vmcoreinfo_data = vmcoreinfo_data_safecopy;
|
|
|
|
vmcoreinfo_append_str("CRASHTIME=%lld\n", ktime_get_real_seconds());
|
|
update_vmcoreinfo_note();
|
|
}
|
|
|
|
void vmcoreinfo_append_str(const char *fmt, ...)
|
|
{
|
|
va_list args;
|
|
char buf[0x50];
|
|
size_t r;
|
|
|
|
va_start(args, fmt);
|
|
r = vscnprintf(buf, sizeof(buf), fmt, args);
|
|
va_end(args);
|
|
|
|
r = min(r, (size_t)VMCOREINFO_BYTES - vmcoreinfo_size);
|
|
|
|
memcpy(&vmcoreinfo_data[vmcoreinfo_size], buf, r);
|
|
|
|
vmcoreinfo_size += r;
|
|
|
|
WARN_ONCE(vmcoreinfo_size == VMCOREINFO_BYTES,
|
|
"vmcoreinfo data exceeds allocated size, truncating");
|
|
}
|
|
|
|
/*
|
|
* provide an empty default implementation here -- architecture
|
|
* code may override this
|
|
*/
|
|
void __weak arch_crash_save_vmcoreinfo(void)
|
|
{}
|
|
|
|
phys_addr_t __weak paddr_vmcoreinfo_note(void)
|
|
{
|
|
return __pa(vmcoreinfo_note);
|
|
}
|
|
EXPORT_SYMBOL(paddr_vmcoreinfo_note);
|
|
|
|
static int __init crash_save_vmcoreinfo_init(void)
|
|
{
|
|
vmcoreinfo_data = (unsigned char *)get_zeroed_page(GFP_KERNEL);
|
|
if (!vmcoreinfo_data) {
|
|
pr_warn("Memory allocation for vmcoreinfo_data failed\n");
|
|
return -ENOMEM;
|
|
}
|
|
|
|
vmcoreinfo_note = alloc_pages_exact(VMCOREINFO_NOTE_SIZE,
|
|
GFP_KERNEL | __GFP_ZERO);
|
|
if (!vmcoreinfo_note) {
|
|
free_page((unsigned long)vmcoreinfo_data);
|
|
vmcoreinfo_data = NULL;
|
|
pr_warn("Memory allocation for vmcoreinfo_note failed\n");
|
|
return -ENOMEM;
|
|
}
|
|
|
|
VMCOREINFO_OSRELEASE(init_uts_ns.name.release);
|
|
VMCOREINFO_BUILD_ID();
|
|
VMCOREINFO_PAGESIZE(PAGE_SIZE);
|
|
|
|
VMCOREINFO_SYMBOL(init_uts_ns);
|
|
VMCOREINFO_OFFSET(uts_namespace, name);
|
|
VMCOREINFO_SYMBOL(node_online_map);
|
|
#ifdef CONFIG_MMU
|
|
VMCOREINFO_SYMBOL_ARRAY(swapper_pg_dir);
|
|
#endif
|
|
VMCOREINFO_SYMBOL(_stext);
|
|
VMCOREINFO_SYMBOL(vmap_area_list);
|
|
|
|
#ifndef CONFIG_NUMA
|
|
VMCOREINFO_SYMBOL(mem_map);
|
|
VMCOREINFO_SYMBOL(contig_page_data);
|
|
#endif
|
|
#ifdef CONFIG_SPARSEMEM
|
|
VMCOREINFO_SYMBOL_ARRAY(mem_section);
|
|
VMCOREINFO_LENGTH(mem_section, NR_SECTION_ROOTS);
|
|
VMCOREINFO_STRUCT_SIZE(mem_section);
|
|
VMCOREINFO_OFFSET(mem_section, section_mem_map);
|
|
VMCOREINFO_NUMBER(SECTION_SIZE_BITS);
|
|
VMCOREINFO_NUMBER(MAX_PHYSMEM_BITS);
|
|
#endif
|
|
VMCOREINFO_STRUCT_SIZE(page);
|
|
VMCOREINFO_STRUCT_SIZE(pglist_data);
|
|
VMCOREINFO_STRUCT_SIZE(zone);
|
|
VMCOREINFO_STRUCT_SIZE(free_area);
|
|
VMCOREINFO_STRUCT_SIZE(list_head);
|
|
VMCOREINFO_SIZE(nodemask_t);
|
|
VMCOREINFO_OFFSET(page, flags);
|
|
VMCOREINFO_OFFSET(page, _refcount);
|
|
VMCOREINFO_OFFSET(page, mapping);
|
|
VMCOREINFO_OFFSET(page, lru);
|
|
VMCOREINFO_OFFSET(page, _mapcount);
|
|
VMCOREINFO_OFFSET(page, private);
|
|
VMCOREINFO_OFFSET(page, compound_head);
|
|
VMCOREINFO_OFFSET(pglist_data, node_zones);
|
|
VMCOREINFO_OFFSET(pglist_data, nr_zones);
|
|
#ifdef CONFIG_FLATMEM
|
|
VMCOREINFO_OFFSET(pglist_data, node_mem_map);
|
|
#endif
|
|
VMCOREINFO_OFFSET(pglist_data, node_start_pfn);
|
|
VMCOREINFO_OFFSET(pglist_data, node_spanned_pages);
|
|
VMCOREINFO_OFFSET(pglist_data, node_id);
|
|
VMCOREINFO_OFFSET(zone, free_area);
|
|
VMCOREINFO_OFFSET(zone, vm_stat);
|
|
VMCOREINFO_OFFSET(zone, spanned_pages);
|
|
VMCOREINFO_OFFSET(free_area, free_list);
|
|
VMCOREINFO_OFFSET(list_head, next);
|
|
VMCOREINFO_OFFSET(list_head, prev);
|
|
VMCOREINFO_OFFSET(vmap_area, va_start);
|
|
VMCOREINFO_OFFSET(vmap_area, list);
|
|
VMCOREINFO_LENGTH(zone.free_area, MAX_ORDER + 1);
|
|
log_buf_vmcoreinfo_setup();
|
|
VMCOREINFO_LENGTH(free_area.free_list, MIGRATE_TYPES);
|
|
VMCOREINFO_NUMBER(NR_FREE_PAGES);
|
|
VMCOREINFO_NUMBER(PG_lru);
|
|
VMCOREINFO_NUMBER(PG_private);
|
|
VMCOREINFO_NUMBER(PG_swapcache);
|
|
VMCOREINFO_NUMBER(PG_swapbacked);
|
|
VMCOREINFO_NUMBER(PG_slab);
|
|
#ifdef CONFIG_MEMORY_FAILURE
|
|
VMCOREINFO_NUMBER(PG_hwpoison);
|
|
#endif
|
|
VMCOREINFO_NUMBER(PG_head_mask);
|
|
#define PAGE_BUDDY_MAPCOUNT_VALUE (~PG_buddy)
|
|
VMCOREINFO_NUMBER(PAGE_BUDDY_MAPCOUNT_VALUE);
|
|
#ifdef CONFIG_HUGETLB_PAGE
|
|
VMCOREINFO_NUMBER(PG_hugetlb);
|
|
#define PAGE_OFFLINE_MAPCOUNT_VALUE (~PG_offline)
|
|
VMCOREINFO_NUMBER(PAGE_OFFLINE_MAPCOUNT_VALUE);
|
|
#endif
|
|
|
|
#ifdef CONFIG_KALLSYMS
|
|
VMCOREINFO_SYMBOL(kallsyms_names);
|
|
VMCOREINFO_SYMBOL(kallsyms_num_syms);
|
|
VMCOREINFO_SYMBOL(kallsyms_token_table);
|
|
VMCOREINFO_SYMBOL(kallsyms_token_index);
|
|
#ifdef CONFIG_KALLSYMS_BASE_RELATIVE
|
|
VMCOREINFO_SYMBOL(kallsyms_offsets);
|
|
VMCOREINFO_SYMBOL(kallsyms_relative_base);
|
|
#else
|
|
VMCOREINFO_SYMBOL(kallsyms_addresses);
|
|
#endif /* CONFIG_KALLSYMS_BASE_RELATIVE */
|
|
#endif /* CONFIG_KALLSYMS */
|
|
|
|
arch_crash_save_vmcoreinfo();
|
|
update_vmcoreinfo_note();
|
|
|
|
return 0;
|
|
}
|
|
|
|
subsys_initcall(crash_save_vmcoreinfo_init);
|
|
|
|
static int __init crash_notes_memory_init(void)
|
|
{
|
|
/* Allocate memory for saving cpu registers. */
|
|
size_t size, align;
|
|
|
|
/*
|
|
* crash_notes could be allocated across 2 vmalloc pages when percpu
|
|
* is vmalloc based . vmalloc doesn't guarantee 2 continuous vmalloc
|
|
* pages are also on 2 continuous physical pages. In this case the
|
|
* 2nd part of crash_notes in 2nd page could be lost since only the
|
|
* starting address and size of crash_notes are exported through sysfs.
|
|
* Here round up the size of crash_notes to the nearest power of two
|
|
* and pass it to __alloc_percpu as align value. This can make sure
|
|
* crash_notes is allocated inside one physical page.
|
|
*/
|
|
size = sizeof(note_buf_t);
|
|
align = min(roundup_pow_of_two(sizeof(note_buf_t)), PAGE_SIZE);
|
|
|
|
/*
|
|
* Break compile if size is bigger than PAGE_SIZE since crash_notes
|
|
* definitely will be in 2 pages with that.
|
|
*/
|
|
BUILD_BUG_ON(size > PAGE_SIZE);
|
|
|
|
crash_notes = __alloc_percpu(size, align);
|
|
if (!crash_notes) {
|
|
pr_warn("Memory allocation for saving cpu register states failed\n");
|
|
return -ENOMEM;
|
|
}
|
|
return 0;
|
|
}
|
|
subsys_initcall(crash_notes_memory_init);
|
|
|
|
#ifdef CONFIG_CRASH_HOTPLUG
|
|
#undef pr_fmt
|
|
#define pr_fmt(fmt) "crash hp: " fmt
|
|
|
|
/*
|
|
* Different than kexec/kdump loading/unloading/jumping/shrinking which
|
|
* usually rarely happen, there will be many crash hotplug events notified
|
|
* during one short period, e.g one memory board is hot added and memory
|
|
* regions are online. So mutex lock __crash_hotplug_lock is used to
|
|
* serialize the crash hotplug handling specifically.
|
|
*/
|
|
DEFINE_MUTEX(__crash_hotplug_lock);
|
|
#define crash_hotplug_lock() mutex_lock(&__crash_hotplug_lock)
|
|
#define crash_hotplug_unlock() mutex_unlock(&__crash_hotplug_lock)
|
|
|
|
/*
|
|
* This routine utilized when the crash_hotplug sysfs node is read.
|
|
* It reflects the kernel's ability/permission to update the crash
|
|
* elfcorehdr directly.
|
|
*/
|
|
int crash_check_update_elfcorehdr(void)
|
|
{
|
|
int rc = 0;
|
|
|
|
crash_hotplug_lock();
|
|
/* Obtain lock while reading crash information */
|
|
if (!kexec_trylock()) {
|
|
pr_info("kexec_trylock() failed, elfcorehdr may be inaccurate\n");
|
|
crash_hotplug_unlock();
|
|
return 0;
|
|
}
|
|
if (kexec_crash_image) {
|
|
if (kexec_crash_image->file_mode)
|
|
rc = 1;
|
|
else
|
|
rc = kexec_crash_image->update_elfcorehdr;
|
|
}
|
|
/* Release lock now that update complete */
|
|
kexec_unlock();
|
|
crash_hotplug_unlock();
|
|
|
|
return rc;
|
|
}
|
|
|
|
/*
|
|
* To accurately reflect hot un/plug changes of cpu and memory resources
|
|
* (including onling and offlining of those resources), the elfcorehdr
|
|
* (which is passed to the crash kernel via the elfcorehdr= parameter)
|
|
* must be updated with the new list of CPUs and memories.
|
|
*
|
|
* In order to make changes to elfcorehdr, two conditions are needed:
|
|
* First, the segment containing the elfcorehdr must be large enough
|
|
* to permit a growing number of resources; the elfcorehdr memory size
|
|
* is based on NR_CPUS_DEFAULT and CRASH_MAX_MEMORY_RANGES.
|
|
* Second, purgatory must explicitly exclude the elfcorehdr from the
|
|
* list of segments it checks (since the elfcorehdr changes and thus
|
|
* would require an update to purgatory itself to update the digest).
|
|
*/
|
|
static void crash_handle_hotplug_event(unsigned int hp_action, unsigned int cpu)
|
|
{
|
|
struct kimage *image;
|
|
|
|
crash_hotplug_lock();
|
|
/* Obtain lock while changing crash information */
|
|
if (!kexec_trylock()) {
|
|
pr_info("kexec_trylock() failed, elfcorehdr may be inaccurate\n");
|
|
crash_hotplug_unlock();
|
|
return;
|
|
}
|
|
|
|
/* Check kdump is not loaded */
|
|
if (!kexec_crash_image)
|
|
goto out;
|
|
|
|
image = kexec_crash_image;
|
|
|
|
/* Check that updating elfcorehdr is permitted */
|
|
if (!(image->file_mode || image->update_elfcorehdr))
|
|
goto out;
|
|
|
|
if (hp_action == KEXEC_CRASH_HP_ADD_CPU ||
|
|
hp_action == KEXEC_CRASH_HP_REMOVE_CPU)
|
|
pr_debug("hp_action %u, cpu %u\n", hp_action, cpu);
|
|
else
|
|
pr_debug("hp_action %u\n", hp_action);
|
|
|
|
/*
|
|
* The elfcorehdr_index is set to -1 when the struct kimage
|
|
* is allocated. Find the segment containing the elfcorehdr,
|
|
* if not already found.
|
|
*/
|
|
if (image->elfcorehdr_index < 0) {
|
|
unsigned long mem;
|
|
unsigned char *ptr;
|
|
unsigned int n;
|
|
|
|
for (n = 0; n < image->nr_segments; n++) {
|
|
mem = image->segment[n].mem;
|
|
ptr = kmap_local_page(pfn_to_page(mem >> PAGE_SHIFT));
|
|
if (ptr) {
|
|
/* The segment containing elfcorehdr */
|
|
if (memcmp(ptr, ELFMAG, SELFMAG) == 0)
|
|
image->elfcorehdr_index = (int)n;
|
|
kunmap_local(ptr);
|
|
}
|
|
}
|
|
}
|
|
|
|
if (image->elfcorehdr_index < 0) {
|
|
pr_err("unable to locate elfcorehdr segment");
|
|
goto out;
|
|
}
|
|
|
|
/* Needed in order for the segments to be updated */
|
|
arch_kexec_unprotect_crashkres();
|
|
|
|
/* Differentiate between normal load and hotplug update */
|
|
image->hp_action = hp_action;
|
|
|
|
/* Now invoke arch-specific update handler */
|
|
arch_crash_handle_hotplug_event(image);
|
|
|
|
/* No longer handling a hotplug event */
|
|
image->hp_action = KEXEC_CRASH_HP_NONE;
|
|
image->elfcorehdr_updated = true;
|
|
|
|
/* Change back to read-only */
|
|
arch_kexec_protect_crashkres();
|
|
|
|
/* Errors in the callback is not a reason to rollback state */
|
|
out:
|
|
/* Release lock now that update complete */
|
|
kexec_unlock();
|
|
crash_hotplug_unlock();
|
|
}
|
|
|
|
static int crash_memhp_notifier(struct notifier_block *nb, unsigned long val, void *v)
|
|
{
|
|
switch (val) {
|
|
case MEM_ONLINE:
|
|
crash_handle_hotplug_event(KEXEC_CRASH_HP_ADD_MEMORY,
|
|
KEXEC_CRASH_HP_INVALID_CPU);
|
|
break;
|
|
|
|
case MEM_OFFLINE:
|
|
crash_handle_hotplug_event(KEXEC_CRASH_HP_REMOVE_MEMORY,
|
|
KEXEC_CRASH_HP_INVALID_CPU);
|
|
break;
|
|
}
|
|
return NOTIFY_OK;
|
|
}
|
|
|
|
static struct notifier_block crash_memhp_nb = {
|
|
.notifier_call = crash_memhp_notifier,
|
|
.priority = 0
|
|
};
|
|
|
|
static int crash_cpuhp_online(unsigned int cpu)
|
|
{
|
|
crash_handle_hotplug_event(KEXEC_CRASH_HP_ADD_CPU, cpu);
|
|
return 0;
|
|
}
|
|
|
|
static int crash_cpuhp_offline(unsigned int cpu)
|
|
{
|
|
crash_handle_hotplug_event(KEXEC_CRASH_HP_REMOVE_CPU, cpu);
|
|
return 0;
|
|
}
|
|
|
|
static int __init crash_hotplug_init(void)
|
|
{
|
|
int result = 0;
|
|
|
|
if (IS_ENABLED(CONFIG_MEMORY_HOTPLUG))
|
|
register_memory_notifier(&crash_memhp_nb);
|
|
|
|
if (IS_ENABLED(CONFIG_HOTPLUG_CPU)) {
|
|
result = cpuhp_setup_state_nocalls(CPUHP_BP_PREPARE_DYN,
|
|
"crash/cpuhp", crash_cpuhp_online, crash_cpuhp_offline);
|
|
}
|
|
|
|
return result;
|
|
}
|
|
|
|
subsys_initcall(crash_hotplug_init);
|
|
#endif
|