kernel-ark/arch/alpha/boot/misc.c
Jeremy Fitzhardinge 35c7422649 [PATCH] x86: deflate stack usage in lib/inflate.c
inflate_fixed and huft_build together use around 2.7k of stack.  When
using 4k stacks, I saw stack overflows from interrupts arriving while
unpacking the root initrd:

do_IRQ: stack overflow: 384
 [<c0106b64>] show_trace_log_lvl+0x1a/0x30
 [<c01075e6>] show_trace+0x12/0x14
 [<c010763f>] dump_stack+0x16/0x18
 [<c0107ca4>] do_IRQ+0x6d/0xd9
 [<c010202b>] xen_evtchn_do_upcall+0x6e/0xa2
 [<c0106781>] xen_hypervisor_callback+0x25/0x2c
 [<c010116c>] xen_restore_fl+0x27/0x29
 [<c0330f63>] _spin_unlock_irqrestore+0x4a/0x50
 [<c0117aab>] change_page_attr+0x577/0x584
 [<c0117b45>] kernel_map_pages+0x8d/0xb4
 [<c016a314>] cache_alloc_refill+0x53f/0x632
 [<c016a6c2>] __kmalloc+0xc1/0x10d
 [<c0463d34>] malloc+0x10/0x12
 [<c04641c1>] huft_build+0x2a7/0x5fa
 [<c04645a5>] inflate_fixed+0x91/0x136
 [<c04657e2>] unpack_to_rootfs+0x5f2/0x8c1
 [<c0465acf>] populate_rootfs+0x1e/0xe4

(This was under Xen, but there's no reason it couldn't happen on bare
  hardware.)

This patch mallocs the local variables, thereby reducing the stack
usage to sane levels.

Also, up the heap size for the kernel decompressor to deal with the
extra allocation.

Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Cc: Tim Yamin <plasmaroo@gentoo.org>
Cc: Andi Kleen <ak@suse.de>
Cc: Matt Mackall <mpm@selenic.com>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Ian Molton <spyro@f2s.com>
2007-05-02 19:27:15 +02:00

208 lines
5.0 KiB
C

/*
* misc.c
*
* This is a collection of several routines from gzip-1.0.3
* adapted for Linux.
*
* malloc by Hannu Savolainen 1993 and Matthias Urlichs 1994
*
* Modified for ARM Linux by Russell King
*
* Nicolas Pitre <nico@visuaide.com> 1999/04/14 :
* For this code to run directly from Flash, all constant variables must
* be marked with 'const' and all other variables initialized at run-time
* only. This way all non constant variables will end up in the bss segment,
* which should point to addresses in RAM and cleared to 0 on start.
* This allows for a much quicker boot time.
*
* Modified for Alpha, from the ARM version, by Jay Estabrook 2003.
*/
#include <linux/kernel.h>
#include <asm/uaccess.h>
#define memzero(s,n) memset ((s),0,(n))
#define puts srm_printk
extern long srm_printk(const char *, ...)
__attribute__ ((format (printf, 1, 2)));
/*
* gzip delarations
*/
#define OF(args) args
#define STATIC static
typedef unsigned char uch;
typedef unsigned short ush;
typedef unsigned long ulg;
#define WSIZE 0x8000 /* Window size must be at least 32k, */
/* and a power of two */
static uch *inbuf; /* input buffer */
static uch *window; /* Sliding window buffer */
static unsigned insize; /* valid bytes in inbuf */
static unsigned inptr; /* index of next byte to be processed in inbuf */
static unsigned outcnt; /* bytes in output buffer */
/* gzip flag byte */
#define ASCII_FLAG 0x01 /* bit 0 set: file probably ascii text */
#define CONTINUATION 0x02 /* bit 1 set: continuation of multi-part gzip file */
#define EXTRA_FIELD 0x04 /* bit 2 set: extra field present */
#define ORIG_NAME 0x08 /* bit 3 set: original file name present */
#define COMMENT 0x10 /* bit 4 set: file comment present */
#define ENCRYPTED 0x20 /* bit 5 set: file is encrypted */
#define RESERVED 0xC0 /* bit 6,7: reserved */
#define get_byte() (inptr < insize ? inbuf[inptr++] : fill_inbuf())
/* Diagnostic functions */
#ifdef DEBUG
# define Assert(cond,msg) {if(!(cond)) error(msg);}
# define Trace(x) fprintf x
# define Tracev(x) {if (verbose) fprintf x ;}
# define Tracevv(x) {if (verbose>1) fprintf x ;}
# define Tracec(c,x) {if (verbose && (c)) fprintf x ;}
# define Tracecv(c,x) {if (verbose>1 && (c)) fprintf x ;}
#else
# define Assert(cond,msg)
# define Trace(x)
# define Tracev(x)
# define Tracevv(x)
# define Tracec(c,x)
# define Tracecv(c,x)
#endif
static int fill_inbuf(void);
static void flush_window(void);
static void error(char *m);
static void gzip_mark(void **);
static void gzip_release(void **);
static char *input_data;
static int input_data_size;
static uch *output_data;
static ulg output_ptr;
static ulg bytes_out;
static void *malloc(int size);
static void free(void *where);
static void error(char *m);
static void gzip_mark(void **);
static void gzip_release(void **);
extern int end;
static ulg free_mem_ptr;
static ulg free_mem_ptr_end;
#define HEAP_SIZE 0x3000
#include "../../../lib/inflate.c"
static void *malloc(int size)
{
void *p;
if (size <0) error("Malloc error");
if (free_mem_ptr <= 0) error("Memory error");
free_mem_ptr = (free_mem_ptr + 3) & ~3; /* Align */
p = (void *)free_mem_ptr;
free_mem_ptr += size;
if (free_mem_ptr >= free_mem_ptr_end)
error("Out of memory");
return p;
}
static void free(void *where)
{ /* gzip_mark & gzip_release do the free */
}
static void gzip_mark(void **ptr)
{
*ptr = (void *) free_mem_ptr;
}
static void gzip_release(void **ptr)
{
free_mem_ptr = (long) *ptr;
}
/* ===========================================================================
* Fill the input buffer. This is called only when the buffer is empty
* and at least one byte is really needed.
*/
int fill_inbuf(void)
{
if (insize != 0)
error("ran out of input data");
inbuf = input_data;
insize = input_data_size;
inptr = 1;
return inbuf[0];
}
/* ===========================================================================
* Write the output window window[0..outcnt-1] and update crc and bytes_out.
* (Used for the decompressed data only.)
*/
void flush_window(void)
{
ulg c = crc;
unsigned n;
uch *in, *out, ch;
in = window;
out = &output_data[output_ptr];
for (n = 0; n < outcnt; n++) {
ch = *out++ = *in++;
c = crc_32_tab[((int)c ^ ch) & 0xff] ^ (c >> 8);
}
crc = c;
bytes_out += (ulg)outcnt;
output_ptr += (ulg)outcnt;
outcnt = 0;
/* puts("."); */
}
static void error(char *x)
{
puts("\n\n");
puts(x);
puts("\n\n -- System halted");
while(1); /* Halt */
}
unsigned int
decompress_kernel(void *output_start,
void *input_start,
size_t ksize,
size_t kzsize)
{
output_data = (uch *)output_start;
input_data = (uch *)input_start;
input_data_size = kzsize; /* use compressed size */
/* FIXME FIXME FIXME */
free_mem_ptr = (ulg)output_start + ksize;
free_mem_ptr_end = (ulg)output_start + ksize + 0x200000;
/* FIXME FIXME FIXME */
/* put in temp area to reduce initial footprint */
window = malloc(WSIZE);
makecrc();
/* puts("Uncompressing Linux..."); */
gunzip();
/* puts(" done, booting the kernel.\n"); */
return output_ptr;
}