From 102a0743326a03cd1a1202ceda21e175b7d3575c Mon Sep 17 00:00:00 2001
From: hc <hc@nodka.com>
Date: Tue, 20 Feb 2024 01:20:52 +0000
Subject: [PATCH] add new system file
---
kernel/kernel/kexec_core.c | 34 +++++++++++++++++++---------------
1 files changed, 19 insertions(+), 15 deletions(-)
diff --git a/kernel/kernel/kexec_core.c b/kernel/kernel/kexec_core.c
index fb0ca1a..3a37fc6 100644
--- a/kernel/kernel/kexec_core.c
+++ b/kernel/kernel/kexec_core.c
@@ -45,7 +45,7 @@
#include <crypto/sha.h>
#include "kexec_internal.h"
-DEFINE_MUTEX(kexec_mutex);
+atomic_t __kexec_lock = ATOMIC_INIT(0);
/* Per cpu memory for storing cpu states in case of system crash. */
note_buf_t __percpu *crash_notes;
@@ -943,7 +943,7 @@
*/
void __noclone __crash_kexec(struct pt_regs *regs)
{
- /* Take the kexec_mutex here to prevent sys_kexec_load
+ /* Take the kexec_lock here to prevent sys_kexec_load
* running on one cpu from replacing the crash kernel
* we are using after a panic on a different cpu.
*
@@ -951,7 +951,7 @@
* of memory the xchg(&kexec_crash_image) would be
* sufficient. But since I reuse the memory...
*/
- if (mutex_trylock(&kexec_mutex)) {
+ if (kexec_trylock()) {
if (kexec_crash_image) {
struct pt_regs fixed_regs;
@@ -960,7 +960,7 @@
machine_crash_shutdown(&fixed_regs);
machine_kexec(kexec_crash_image);
}
- mutex_unlock(&kexec_mutex);
+ kexec_unlock();
}
}
STACK_FRAME_NON_STANDARD(__crash_kexec);
@@ -978,6 +978,7 @@
old_cpu = atomic_cmpxchg(&panic_cpu, PANIC_CPU_INVALID, this_cpu);
if (old_cpu == PANIC_CPU_INVALID) {
/* This is the 1st CPU which comes here, so go ahead. */
+ printk_safe_flush_on_panic();
__crash_kexec(regs);
/*
@@ -988,14 +989,17 @@
}
}
-size_t crash_get_memory_size(void)
+ssize_t crash_get_memory_size(void)
{
- size_t size = 0;
+ ssize_t size = 0;
- mutex_lock(&kexec_mutex);
+ if (!kexec_trylock())
+ return -EBUSY;
+
if (crashk_res.end != crashk_res.start)
size = resource_size(&crashk_res);
- mutex_unlock(&kexec_mutex);
+
+ kexec_unlock();
return size;
}
@@ -1015,7 +1019,8 @@
unsigned long old_size;
struct resource *ram_res;
- mutex_lock(&kexec_mutex);
+ if (!kexec_trylock())
+ return -EBUSY;
if (kexec_crash_image) {
ret = -ENOENT;
@@ -1024,6 +1029,7 @@
start = crashk_res.start;
end = crashk_res.end;
old_size = (end == 0) ? 0 : end - start + 1;
+ new_size = roundup(new_size, KEXEC_CRASH_MEM_ALIGN);
if (new_size >= old_size) {
ret = (new_size == old_size) ? 0 : -EINVAL;
goto unlock;
@@ -1035,9 +1041,7 @@
goto unlock;
}
- start = roundup(start, KEXEC_CRASH_MEM_ALIGN);
- end = roundup(start + new_size, KEXEC_CRASH_MEM_ALIGN);
-
+ end = start + new_size;
crash_free_reserved_phys_range(end, crashk_res.end);
if ((start == end) && (crashk_res.parent != NULL))
@@ -1053,7 +1057,7 @@
insert_resource(&iomem_resource, ram_res);
unlock:
- mutex_unlock(&kexec_mutex);
+ kexec_unlock();
return ret;
}
@@ -1125,7 +1129,7 @@
{
int error = 0;
- if (!mutex_trylock(&kexec_mutex))
+ if (!kexec_trylock())
return -EBUSY;
if (!kexec_image) {
error = -EINVAL;
@@ -1200,7 +1204,7 @@
#endif
Unlock:
- mutex_unlock(&kexec_mutex);
+ kexec_unlock();
return error;
}
--
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