[PATCH v4 13/17] kexec: add machine_kexec_post_load()

From: Pavel Tatashin
Date: Mon Sep 09 2019 - 14:13:12 EST


It is the same as machine_kexec_prepare(), but is called after segments are
loaded. This way, can do processing work with already loaded relocation
segments. One such example is arm64: it has to have segments loaded in
order to create a page table, but it cannot do it during kexec time,
because at that time allocations won't be possible anymore.

Signed-off-by: Pavel Tatashin <pasha.tatashin@xxxxxxxxxx>
---
kernel/kexec.c | 4 ++++
kernel/kexec_core.c | 6 ++++++
kernel/kexec_file.c | 4 ++++
kernel/kexec_internal.h | 2 ++
4 files changed, 16 insertions(+)

diff --git a/kernel/kexec.c b/kernel/kexec.c
index 1b018f1a6e0d..27b71dc7b35a 100644
--- a/kernel/kexec.c
+++ b/kernel/kexec.c
@@ -159,6 +159,10 @@ static int do_kexec_load(unsigned long entry, unsigned long nr_segments,

kimage_terminate(image);

+ ret = machine_kexec_post_load(image);
+ if (ret)
+ goto out;
+
/* Install the new kernel and uninstall the old */
image = xchg(dest_image, image);

diff --git a/kernel/kexec_core.c b/kernel/kexec_core.c
index 2c5b72863b7b..8360645d1bbe 100644
--- a/kernel/kexec_core.c
+++ b/kernel/kexec_core.c
@@ -587,6 +587,12 @@ static void kimage_free_extra_pages(struct kimage *image)
kimage_free_page_list(&image->unusable_pages);

}
+
+int __weak machine_kexec_post_load(struct kimage *image)
+{
+ return 0;
+}
+
void kimage_terminate(struct kimage *image)
{
if (*image->entry != 0)
diff --git a/kernel/kexec_file.c b/kernel/kexec_file.c
index b8cc032d5620..cb531d768114 100644
--- a/kernel/kexec_file.c
+++ b/kernel/kexec_file.c
@@ -391,6 +391,10 @@ SYSCALL_DEFINE5(kexec_file_load, int, kernel_fd, int, initrd_fd,

kimage_terminate(image);

+ ret = machine_kexec_post_load(image);
+ if (ret)
+ goto out;
+
/*
* Free up any temporary buffers allocated which are not needed
* after image has been loaded
diff --git a/kernel/kexec_internal.h b/kernel/kexec_internal.h
index 48aaf2ac0d0d..39d30ccf8d87 100644
--- a/kernel/kexec_internal.h
+++ b/kernel/kexec_internal.h
@@ -13,6 +13,8 @@ void kimage_terminate(struct kimage *image);
int kimage_is_destination_range(struct kimage *image,
unsigned long start, unsigned long end);

+int machine_kexec_post_load(struct kimage *image);
+
extern struct mutex kexec_mutex;

#ifdef CONFIG_KEXEC_FILE
--
2.23.0