initramfs: cleanup initrd freeing

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

Link: http://lkml.kernel.org/r/20190213174621.29297-4-hch@lst.de
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Mike Rapoport <rppt@linux.ibm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>	[arm64]
Cc: Geert Uytterhoeven <geert@linux-m68k.org>	[m68k]
Cc: Steven Price <steven.price@arm.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Guan Xuetao <gxt@pku.edu.cn>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/init/initramfs.c b/init/initramfs.c
index c322e1099f435cfee4bb1b96a880cf07fd31e751..5fda9557a134d98de35b42b84d9ddcad7cb61fc3 100644 (file)
--- 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 */
 
 #ifdef CONFIG_BLK_DEV_RAM
 #define BUF_SIZE 1024
@@ -642,7 +640,16 @@ static int __init populate_rootfs(void)
                        printk(KERN_EMERG "Initramfs unpacking failed: %s\n", err);
 #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;
 }