"/sys/kernel/kexec_crash_size" only includes crashk_res, it
is fine in most cases, but sometimes we have crashk_low_res.
For example, when "crashkernel=size[KMG],high" combined with
"crashkernel=size[KMG],low" is used for 64-bit x86.
Let "/sys/kernel/kexec_crash_size" reflect all the reserved
memory including crashk_low_res, this is more understandable
from its naming.
Although we can get all the crash memory from "/proc/iomem"
by filtering all "Crash kernel" keyword, it is more convenient
to utilize this file, and the two ways should stay consistent.
Note that write to "/sys/kernel/kexec_crash_size" is to shrink
the reserved memory, and we want to shrink crashk_res only.
So we add some additional check in crash_shrink_memory() since
crashk_low_res now is involved.
Signed-off-by: Xunlei Pang <xlpang at redhat.com>
---
kernel/kexec_core.c | 15 ++++++++++++++-
1 file changed, 14 insertions(+), 1 deletion(-)
diff --git a/kernel/kexec_core.c b/kernel/kexec_core.c
index 5616755..d5ae780 100644
--- a/kernel/kexec_core.c
+++ b/kernel/kexec_core.c
@@ -932,6 +932,8 @@ size_t crash_get_memory_size(void)
mutex_lock(&kexec_mutex);
if (crashk_res.end != crashk_res.start)
size = resource_size(&crashk_res);
+ if (crashk_low_res.end != crashk_low_res.start)
+ size += resource_size(&crashk_low_res);
mutex_unlock(&kexec_mutex);
return size;
}
@@ -949,7 +951,7 @@ int crash_shrink_memory(unsigned long new_size)
{
int ret = 0;
unsigned long start, end;
- unsigned long old_size;
+ unsigned long low_size, old_size;
struct resource *ram_res;
mutex_lock(&kexec_mutex);
@@ -958,6 +960,17 @@ int crash_shrink_memory(unsigned long new_size)
ret = -ENOENT;
goto unlock;
}
+
+ start = crashk_low_res.start;
+ end = crashk_low_res.end;
+ low_size = (end == 0) ? 0 : end - start + 1;
+ /* Do not shrink crashk_low_res. */
+ if (new_size <= low_size) {
+ ret = -EINVAL;
+ goto unlock;
+ }
+
+ new_size -= low_size;
start = crashk_res.start;
end = crashk_res.end;
old_size = (end == 0) ? 0 : end - start + 1;
--
1.8.3.1
