The patch titled
Subject: kexec: add helper __crash_shrink_memory()
has been added to the -mm mm-nonmm-unstable branch. Its filename is
kexec-add-helper-__crash_shrink_memory.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/kexec-add-helper-__crash_shrink_memory.patch
This patch will later appear in the mm-nonmm-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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------------------------------------------------------
From: Zhen Lei <thunder.leizhen@xxxxxxxxxx>
Subject: kexec: add helper __crash_shrink_memory()
Date: Sat, 27 May 2023 20:34:38 +0800
No functional change, in preparation for the next patch so that it is
easier to review.
Link: https://lkml.kernel.org/r/20230527123439.772-6-thunder.leizhen@xxxxxxxxxx
Signed-off-by: Zhen Lei <thunder.leizhen@xxxxxxxxxx>
Cc: Baoquan He <bhe@xxxxxxxxxx>
Cc: Cong Wang <amwang@xxxxxxxxxx>
Cc: Eric W. Biederman <ebiederm@xxxxxxxxxxxx>
Cc: Michael Holzheu <holzheu@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
kernel/kexec_core.c | 50 +++++++++++++++++++++++-------------------
1 file changed, 28 insertions(+), 22 deletions(-)
--- a/kernel/kexec_core.c~kexec-add-helper-__crash_shrink_memory
+++ a/kernel/kexec_core.c
@@ -1105,11 +1105,37 @@ ssize_t crash_get_memory_size(void)
return size;
}
+int __crash_shrink_memory(struct resource *old_res, unsigned long new_size)
+{
+ struct resource *ram_res;
+
+ ram_res = kzalloc(sizeof(*ram_res), GFP_KERNEL);
+ if (!ram_res)
+ return -ENOMEM;
+
+ ram_res->start = old_res->start + new_size;
+ ram_res->end = old_res->end;
+ ram_res->flags = IORESOURCE_BUSY | IORESOURCE_SYSTEM_RAM;
+ ram_res->name = "System RAM";
+
+ if (!new_size) {
+ release_resource(old_res);
+ old_res->start = 0;
+ old_res->end = 0;
+ } else {
+ crashk_res.end = ram_res->start - 1;
+ }
+
+ crash_free_reserved_phys_range(ram_res->start, ram_res->end);
+ insert_resource(&iomem_resource, ram_res);
+
+ return 0;
+}
+
int crash_shrink_memory(unsigned long new_size)
{
int ret = 0;
unsigned long old_size;
- struct resource *ram_res;
if (!kexec_trylock())
return -EBUSY;
@@ -1125,27 +1151,7 @@ int crash_shrink_memory(unsigned long ne
goto unlock;
}
- ram_res = kzalloc(sizeof(*ram_res), GFP_KERNEL);
- if (!ram_res) {
- ret = -ENOMEM;
- goto unlock;
- }
-
- ram_res->start = crashk_res.start + new_size;
- ram_res->end = crashk_res.end;
- ram_res->flags = IORESOURCE_BUSY | IORESOURCE_SYSTEM_RAM;
- ram_res->name = "System RAM";
-
- if (!new_size) {
- release_resource(&crashk_res);
- crashk_res.start = 0;
- crashk_res.end = 0;
- } else {
- crashk_res.end = ram_res->start - 1;
- }
-
- crash_free_reserved_phys_range(ram_res->start, ram_res->end);
- insert_resource(&iomem_resource, ram_res);
+ ret = __crash_shrink_memory(&crashk_res, new_size);
unlock:
kexec_unlock();
_
Patches currently in -mm which might be from thunder.leizhen@xxxxxxxxxx are
kexec-fix-a-memory-leak-in-crash_shrink_memory.patch
kexec-delete-a-useless-check-in-crash_shrink_memory.patch
kexec-clear-crashk_res-if-all-its-memory-has-been-released.patch
kexec-improve-the-readability-of-crash_shrink_memory.patch
kexec-add-helper-__crash_shrink_memory.patch
kexec-enable-kexec_crash_size-to-support-two-crash-kernel-regions.patch
