[PATCH 3/8] initramfs: cleanup initrd freeing

Christoph Hellwig
2019-02-13T17:46:45Z

Factor the kexec logic into a separate helper, and then inline the
rest of free_initrd into the only caller.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
init/initramfs.c | 53 +++++++++++++++++++++++++++---------------------
1 file changed, 30 insertions(+), 23 deletions(-)

diff --git a/init/initramfs.c b/init/initramfs.c
index 1cba6bbeeb75..6c2ed1d7276e 100644
--- a/init/initramfs.c
+++ b/init/initramfs.c
@@ -518,37 +518,35 @@ extern unsigned long __initramfs_size;
#include <linux/initrd.h>
#include <linux/kexec.h>

-static void __init free_initrd(void)
-{
#ifdef CONFIG_KEXEC_CORE
+static bool kexec_free_initrd(void)
+{
unsigned long crashk_start = (unsigned long)__va(crashk_res.start);
unsigned long crashk_end = (unsigned long)__va(crashk_res.end);
-#endif
- if (do_retain_initrd)
- goto skip;

-#ifdef CONFIG_KEXEC_CORE
/*
* If the initrd region is overlapped with crashkernel reserved region,
* free only memory that is not part of crashkernel region.
*/
- if (initrd_start < crashk_end && initrd_end > crashk_start) {
- /*
- * Initialize initrd memory region since the kexec boot does
- * not do.
- */
- memset((void *)initrd_start, 0, initrd_end - initrd_start);
- if (initrd_start < crashk_start)
- free_initrd_mem(initrd_start, crashk_start);
- if (initrd_end > crashk_end)
- free_initrd_mem(crashk_end, initrd_end);
- } else
-#endif
- free_initrd_mem(initrd_start, initrd_end);
-skip:
- initrd_start = 0;
- initrd_end = 0;
+ if (initrd_start >= crashk_end || initrd_end <= crashk_start)
+ return false;
+
+ /*
+ * Initialize initrd memory region since the kexec boot does not do.
+ */
+ memset((void *)initrd_start, 0, initrd_end - initrd_start);
+ if (initrd_start < crashk_start)
+ free_initrd_mem(initrd_start, crashk_start);
+ if (initrd_end > crashk_end)
+ free_initrd_mem(crashk_end, initrd_end);
+ return true;
}
+#else
+static inline bool kexec_free_initrd(void)
+{
+ return false;
+}
+#endif /* CONFIG_KEXEC_CORE */

#define BUF_SIZE 1024
static void __init clean_rootfs(void)
@@ -642,7 +640,16 @@ static int __init populate_rootfs(void)
}
#endif
}
- free_initrd();
+
+ /*
+ * If the initrd region is overlapped with crashkernel reserved region,
+ * free only memory that is not part of crashkernel region.
+ */
+ if (!do_retain_initrd && !kexec_free_initrd())
+ free_initrd_mem(initrd_start, initrd_end);
+ initrd_start = 0;
+ initrd_end = 0;
+
flush_delayed_fput();
return 0;
}
--
2.20.1