Commit dd23e809 authored by Florian Fainelli's avatar Florian Fainelli Committed by Linus Torvalds
Browse files

initramfs: panic with memory information 

On systems with large amounts of reserved memory we may fail to
successfully complete unpack_to_rootfs() and be left with:

 Kernel panic - not syncing: write error

this is not too helpful to understand what happened, so let's wrap the
panic() calls with a surrounding show_mem() such that we have a chance of
understanding the memory conditions leading to these allocation failures.

[akpm@linux-foundation.org: replace macro with C function]

Link: https://lkml.kernel.org/r/20210114231517.1854379-1-f.fainelli@gmail.com


Signed-off-by: default avatarFlorian Fainelli <f.fainelli@gmail.com>
Cc: Barret Rhoden <brho@google.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 6aaa31ae

init/initramfs.c

+15 −4
Original line number Diff line number Diff line
@@ -11,6 +11,7 @@ 
#include <linux/utime.h>

#include <linux/file.h>

#include <linux/memblock.h>

#include <linux/mm.h>

#include <linux/namei.h>

#include <linux/init_syscalls.h>
@@ -45,6 +46,16 @@ static void __init error(char *x) 
		message = x;

}



static void panic_show_mem(const char *fmt, ...)

{

	va_list args;



	show_mem(0, NULL);

	va_start(args, fmt);

	panic(fmt, args);

	va_end(args);

}



/* link hash */



#define N_ALIGN(len) ((((len) + 1) & ~3) + 2)
@@ -80,7 +91,7 @@ static char __init *find_link(int major, int minor, int ino, 
	}

	q = kmalloc(sizeof(struct hash), GFP_KERNEL);

	if (!q)

		panic("can't allocate link hash entry");

		panic_show_mem("can't allocate link hash entry");

	q->major = major;

	q->minor = minor;

	q->ino = ino;
@@ -125,7 +136,7 @@ static void __init dir_add(const char *name, time64_t mtime) 
{

	struct dir_entry *de = kmalloc(sizeof(struct dir_entry), GFP_KERNEL);

	if (!de)

		panic("can't allocate dir_entry buffer");

		panic_show_mem("can't allocate dir_entry buffer");

	INIT_LIST_HEAD(&de->list);

	de->name = kstrdup(name, GFP_KERNEL);

	de->mtime = mtime;
@@ -460,7 +471,7 @@ static char * __init unpack_to_rootfs(char *buf, unsigned long len) 
	name_buf = kmalloc(N_ALIGN(PATH_MAX), GFP_KERNEL);



	if (!header_buf || !symlink_buf || !name_buf)

		panic("can't allocate buffers");

		panic_show_mem("can't allocate buffers");



	state = Start;

	this_header = 0;
@@ -607,7 +618,7 @@ static int __init populate_rootfs(void) 
	/* Load the built in initramfs */

	char *err = unpack_to_rootfs(__initramfs_start, __initramfs_size);

	if (err)

		panic("%s", err); /* Failed to decompress INTERNAL initramfs */

		panic_show_mem("%s", err); /* Failed to decompress INTERNAL initramfs */



	if (!initrd_start || IS_ENABLED(CONFIG_INITRAMFS_FORCE))

		goto done;