inflate: refactor inflate malloc code

Inflate requires some dynamic memory allocation very early in the boot
process and this is provided with a set of four functions:
malloc/free/gzip_mark/gzip_release.

The old inflate code used a mark/release strategy rather than implement
free.  This new version instead keeps a count on the number of outstanding
allocations and when it hits zero, it resets the malloc arena.

This allows removing all the mark and release implementations and unifying
all the malloc/free implementations.

The architecture-dependent code must define two addresses:
 - free_mem_ptr, the address of the beginning of the area in which
   allocations should be made
 - free_mem_end_ptr, the address of the end of the area in which
   allocations should be made. If set to 0, then no check is made on
   the number of allocations, it just grows as much as needed

The architecture-dependent code can also provide an arch_decomp_wdog()
function call.  This function will be called several times during the
decompression process, and allow to notify the watchdog that the system is
still running.  If an architecture provides such a call, then it must
define ARCH_HAS_DECOMP_WDOG so that the generic inflate code calls
arch_decomp_wdog().

Work initially done by Matt Mackall, updated to a recent version of the
kernel and improved by me.

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Cc: Matt Mackall <mpm@selenic.com>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Mikael Starvik <mikael.starvik@axis.com>
Cc: Jesper Nilsson <jesper.nilsson@axis.com>
Cc: Haavard Skinnemoen <hskinnemoen@atmel.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Acked-by: Paul Mundt <lethal@linux-sh.org>
Acked-by: Yoshinori Sato <ysato@users.sourceforge.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

arch/alpha/boot/misc.c

@@ -78,8 +78,6 @@ static unsigned outcnt;		/* bytes in output buffer */
 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;
@@ -88,51 +86,18 @@ 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;
+static ulg free_mem_end_ptr;
 
 #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.
@@ -193,7 +158,7 @@ decompress_kernel(void *output_start,
 
 	/* FIXME FIXME FIXME */
 	free_mem_ptr		= (ulg)output_start + ksize;
-	free_mem_ptr_end	= (ulg)output_start + ksize + 0x200000;
+	free_mem_end_ptr	= (ulg)output_start + ksize + 0x200000;
 	/* FIXME FIXME FIXME */
 
 	/* put in temp area to reduce initial footprint */

arch/arm/boot/compressed/misc.c

@@ -217,8 +217,6 @@ static unsigned outcnt;		/* bytes in output buffer */
 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 **);
 
 extern char input_data[];
 extern char input_data_end[];
@@ -227,64 +225,21 @@ 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 **);
 
 static void putstr(const char *);
 
 extern int end;
 static ulg free_mem_ptr;
-static ulg free_mem_ptr_end;
+static ulg free_mem_end_ptr;
 
-#define HEAP_SIZE 0x3000
-
-#include "../../../../lib/inflate.c"
-
-#ifndef STANDALONE_DEBUG
-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)
-{
-	arch_decomp_wdog();
-	*ptr = (void *) free_mem_ptr;
-}
+#ifdef STANDALONE_DEBUG
+#define NO_INFLATE_MALLOC
+#endif
 
-static void gzip_release(void **ptr)
-{
-	arch_decomp_wdog();
-	free_mem_ptr = (long) *ptr;
-}
-#else
-static void gzip_mark(void **ptr)
-{
-}
+#define ARCH_HAS_DECOMP_WDOG
 
-static void gzip_release(void **ptr)
-{
-}
-#endif
+#include "../../../../lib/inflate.c"
 
 /* ===========================================================================
  * Fill the input buffer. This is called only when the buffer is empty
@@ -348,7 +303,7 @@ decompress_kernel(ulg output_start, ulg free_mem_ptr_p, ulg free_mem_ptr_end_p,
 {
 	output_data		= (uch *)output_start;	/* Points to kernel start */
 	free_mem_ptr		= free_mem_ptr_p;
-	free_mem_ptr_end	= free_mem_ptr_end_p;
+	free_mem_end_ptr	= free_mem_ptr_end_p;
 	__machine_arch_type	= arch_id;
 
 	arch_decomp_setup();

arch/cris/arch-v10/boot/compressed/misc.c

@@ -102,50 +102,16 @@ extern char *input_data;  /* lives in head.S */
 static long bytes_out = 0;
 static uch *output_data;
 static unsigned long output_ptr = 0;
-
-static void *malloc(int size);
-static void free(void *where);
-static void gzip_mark(void **);
-static void gzip_release(void **);
-
 static void puts(const char *);
 
 /* the "heap" is put directly after the BSS ends, at end */
 
 extern int _end;
 static long free_mem_ptr = (long)&_end;
+static long free_mem_end_ptr;
 
 #include "../../../../../lib/inflate.c"
 
-static void *malloc(int size)
-{
-	void *p;
-
-	if (size < 0)
-		error("Malloc error");
-
-	free_mem_ptr = (free_mem_ptr + 3) & ~3;	/* Align */
-
-	p = (void *)free_mem_ptr;
-	free_mem_ptr += size;
-
-	return p;
-}
-
-static void free(void *where)
-{	/* Don't care */
-}
-
-static void gzip_mark(void **ptr)
-{
-	*ptr = (void *) free_mem_ptr;
-}
-
-static void gzip_release(void **ptr)
-{
-	free_mem_ptr = (long) *ptr;
-}
-
 /* decompressor info and error messages to serial console */
 
 static void

arch/cris/arch-v32/boot/compressed/misc.c

@@ -89,20 +89,14 @@ static unsigned outcnt = 0;  /* bytes in output buffer */
 
 static void flush_window(void);
 static void error(char *m);
-static void gzip_mark(void **);
-static void gzip_release(void **);
 
 extern char *input_data;  /* lives in head.S */
 
-static long bytes_out = 0;
+static long bytes_out;
 static uch *output_data;
-static unsigned long output_ptr = 0;
+static unsigned long output_ptr;
 
-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 **);
 
 static void puts(const char *);
 
@@ -110,37 +104,10 @@ static void puts(const char *);
 
 extern int _end;
 static long free_mem_ptr = (long)&_end;
+static long free_mem_end_ptr;
 
 #include "../../../../../lib/inflate.c"
 
-static void *malloc(int size)
-{
-	void *p;
-
-	if (size <0) error("Malloc error");
-
-	free_mem_ptr = (free_mem_ptr + 3) & ~3;	/* Align */
-
-	p = (void *)free_mem_ptr;
-	free_mem_ptr += size;
-
-	return p;
-}
-
-static void free(void *where)
-{	/* Don't care */
-}
-
-static void gzip_mark(void **ptr)
-{
-	*ptr = (void *) free_mem_ptr;
-}
-
-static void gzip_release(void **ptr)
-{
-	free_mem_ptr = (long) *ptr;
-}
-
 /* decompressor info and error messages to serial console */
 
 static inline void

arch/h8300/boot/compressed/misc.c

@@ -67,8 +67,6 @@ static unsigned outcnt = 0;  /* bytes in output buffer */
 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 **);
 
 extern char input_data[];
 extern int input_len;
@@ -77,11 +75,7 @@ static long bytes_out = 0;
 static uch *output_data;
 static unsigned long output_ptr = 0;
 
-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 **);
 
 int puts(const char *);
 
@@ -98,38 +92,6 @@ static unsigned long free_mem_end_ptr;
 #define TDR *((volatile unsigned char *)0xffff8b)
 #define SSR *((volatile unsigned char *)0xffff8c)
 
-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_end_ptr)
-		error("Out of memory");
-
-	return p;
-}
-
-static void free(void *where)
-{	/* Don't care */
-}
-
-static void gzip_mark(void **ptr)
-{
-	*ptr = (void *) free_mem_ptr;
-}
-
-static void gzip_release(void **ptr)
-{
-	free_mem_ptr = (long) *ptr;
-}
-
 int puts(const char *s)
 {
 	return 0;

arch/m32r/boot/compressed/misc.c

@@ -70,8 +70,6 @@ static unsigned outcnt = 0;  /* bytes in output buffer */
 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 unsigned char *input_data;
 static int input_len;
@@ -82,9 +80,6 @@ static unsigned long output_ptr = 0;
 
 #include "m32r_sio.c"
 
-static void *malloc(int size);
-static void free(void *where);
-
 static unsigned long free_mem_ptr;
 static unsigned long free_mem_end_ptr;
 
@@ -92,38 +87,6 @@ static unsigned long free_mem_end_ptr;
 
 #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_end_ptr)
-		error("Out of memory");
-
-	return p;
-}
-
-static void free(void *where)
-{	/* Don't care */
-}
-
-static void gzip_mark(void **ptr)
-{
-	*ptr = (void *) free_mem_ptr;
-}
-
-static void gzip_release(void **ptr)
-{
-	free_mem_ptr = (long) *ptr;
-}
-
 void* memset(void* s, int c, size_t n)
 {
 	int i;

arch/mn10300/boot/compressed/misc.c

@@ -153,26 +153,9 @@ static uch *output_data;
 static unsigned long output_ptr;
 
 
-static void *malloc(int size);
-
-static inline void free(void *where)
-{	/* Don't care */
-}
-
 static unsigned long free_mem_ptr = (unsigned long) &end;
 static unsigned long free_mem_end_ptr = (unsigned long) &end + 0x90000;
 
-static inline void gzip_mark(void **ptr)
-{
-	kputs(".");
-	*ptr = (void *) free_mem_ptr;
-}
-
-static inline void gzip_release(void **ptr)
-{
-	free_mem_ptr = (unsigned long) *ptr;
-}
-
 #define INPLACE_MOVE_ROUTINE	0x1000
 #define LOW_BUFFER_START	0x2000
 #define LOW_BUFFER_END		0x90000
@@ -186,26 +169,6 @@ static int lines, cols;
 
 #include "../../../../lib/inflate.c"
 
-static void *malloc(int size)
-{
-	void *p;
-
-	if (size < 0)
-		error("Malloc error\n");
-	if (!free_mem_ptr)
-		error("Memory error\n");
-
-	free_mem_ptr = (free_mem_ptr + 3) & ~3;	/* Align */
-
-	p = (void *) free_mem_ptr;
-	free_mem_ptr += size;
-
-	if (free_mem_ptr >= free_mem_end_ptr)
-		error("\nOut of memory\n");
-
-	return p;
-}
-
 static inline void scroll(void)
 {
 	int i;

arch/sh/boot/compressed/misc_32.c

@@ -74,8 +74,6 @@ static unsigned outcnt = 0;  /* bytes in output buffer */
 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 **);
 
 extern char input_data[];
 extern int input_len;
@@ -84,11 +82,7 @@ static long bytes_out = 0;
 static uch *output_data;
 static unsigned long output_ptr = 0;
 
-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 **);
 
 int puts(const char *);
 
@@ -101,38 +95,6 @@ static unsigned long free_mem_end_ptr;
 
 #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_end_ptr)
-		error("Out of memory");
-
-	return p;
-}
-
-static void free(void *where)
-{	/* Don't care */
-}
-
-static void gzip_mark(void **ptr)
-{
-	*ptr = (void *) free_mem_ptr;
-}
-
-static void gzip_release(void **ptr)
-{
-	free_mem_ptr = (long) *ptr;
-}
-
 #ifdef CONFIG_SH_STANDARD_BIOS
 size_t strlen(const char *s)
 {

arch/sh/boot/compressed/misc_64.c

@@ -72,8 +72,6 @@ static unsigned outcnt = 0;	/* bytes in output buffer */
 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 **);
 
 extern char input_data[];
 extern int input_len;
@@ -82,11 +80,7 @@ static long bytes_out = 0;
 static uch *output_data;
 static unsigned long output_ptr = 0;
 
-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 **);
 
 static void puts(const char *);
 
@@ -99,40 +93,6 @@ static unsigned long free_mem_end_ptr;
 
 #include "../../../../lib/inflate.c"
 
-static void *malloc(int size)
-{
-	void *p;
-
-	if (size < 0)
-		error("Malloc error\n");
-	if (free_mem_ptr == 0)
-		error("Memory error\n");
-
-	free_mem_ptr = (free_mem_ptr + 3) & ~3;	/* Align */
-
-	p = (void *) free_mem_ptr;
-	free_mem_ptr += size;
-
-	if (free_mem_ptr >= free_mem_end_ptr)
-		error("\nOut of memory\n");
-
-	return p;
-}
-
-static void free(void *where)
-{				/* Don't care */
-}
-
-static void gzip_mark(void **ptr)
-{
-	*ptr = (void *) free_mem_ptr;
-}
-
-static void gzip_release(void **ptr)
-{
-	free_mem_ptr = (long) *ptr;
-}
-
 void puts(const char *s)
 {
 }

arch/x86/boot/compressed/misc.c

@@ -182,8 +182,6 @@ static unsigned		outcnt;
 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 **);
 
 /*
  * This is set up by the setup-routine at boot-time
@@ -196,9 +194,6 @@ extern int input_len;
 
 static long bytes_out;
 
-static void *malloc(int size);
-static void free(void *where);
-
 static void *memset(void *s, int c, unsigned n);
 static void *memcpy(void *dest, const void *src, unsigned n);
 
@@ -220,40 +215,6 @@ static int lines, cols;
 
 #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_end_ptr)
-		error("Out of memory");
-
-	return p;
-}
-
-static void free(void *where)
-{	/* Don't care */
-}
-
-static void gzip_mark(void **ptr)
-{
-	*ptr = (void *) free_mem_ptr;
-}
-
-static void gzip_release(void **ptr)
-{
-	free_mem_ptr = (memptr) *ptr;
-}
-
 static void scroll(void)
 {
 	int i;

init/do_mounts_rd.c

@@ -303,32 +303,11 @@ static int crd_infd, crd_outfd;
 
 static int  __init fill_inbuf(void);
 static void __init flush_window(void);
-static void __init *malloc(size_t size);
-static void __init free(void *where);
 static void __init error(char *m);
-static void __init gzip_mark(void **);
-static void __init gzip_release(void **);
 
-#include "../lib/inflate.c"
-
-static void __init *malloc(size_t size)
-{
-	return kmalloc(size, GFP_KERNEL);
-}
-
-static void __init free(void *where)
-{
-	kfree(where);
-}
-
-static void __init gzip_mark(void **ptr)
-{
-}
-
-static void __init gzip_release(void **ptr)
-{
-}
+#define NO_INFLATE_MALLOC
 
+#include "../lib/inflate.c"
 
 /* ===========================================================================
  * Fill the input buffer. This is called only when the buffer is empty

init/initramfs.c

@@ -14,16 +14,6 @@ static void __init error(char *x)
 		message = x;
 }
 
-static void __init *malloc(size_t size)
-{
-	return kmalloc(size, GFP_KERNEL);
-}
-
-static void __init free(void *where)
-{
-	kfree(where);
-}
-
 /* link hash */
 
 #define N_ALIGN(len) ((((len) + 1) & ~3) + 2)
@@ -407,18 +397,10 @@ static long bytes_out;
 
 static void __init flush_window(void);
 static void __init error(char *m);
-static void __init gzip_mark(void **);
-static void __init gzip_release(void **);
 
-#include "../lib/inflate.c"
+#define NO_INFLATE_MALLOC
 
-static void __init gzip_mark(void **ptr)
-{
-}
-
-static void __init gzip_release(void **ptr)
-{
-}
+#include "../lib/inflate.c"
 
 /* ===========================================================================
  * Write the output window window[0..outcnt-1] and update crc and bytes_out.

lib/inflate.c

@@ -230,6 +230,45 @@ STATIC const ush mask_bits[] = {
 #define NEEDBITS(n) {while(k<(n)){b|=((ulg)NEXTBYTE())<<k;k+=8;}}
 #define DUMPBITS(n) {b>>=(n);k-=(n);}
 
+#ifndef NO_INFLATE_MALLOC
+/* A trivial malloc implementation, adapted from
+ *  malloc by Hannu Savolainen 1993 and Matthias Urlichs 1994
+ */
+
+static unsigned long malloc_ptr;
+static int malloc_count;
+
+static void *malloc(int size)
+{
+       void *p;
+
+       if (size < 0)
+		error("Malloc error");
+       if (!malloc_ptr)
+		malloc_ptr = free_mem_ptr;
+
+       malloc_ptr = (malloc_ptr + 3) & ~3;     /* Align */
+
+       p = (void *)malloc_ptr;
+       malloc_ptr += size;
+
+       if (free_mem_end_ptr && malloc_ptr >= free_mem_end_ptr)
+		error("Out of memory");
+
+       malloc_count++;
+       return p;
+}
+
+static void free(void *where)
+{
+       malloc_count--;
+       if (!malloc_count)
+		malloc_ptr = free_mem_ptr;
+}
+#else
+#define malloc(a) kmalloc(a, GFP_KERNEL)
+#define free(a) kfree(a)
+#endif
 
 /*
    Huffman code decoding is performed using a multi-level table lookup.
@@ -1045,7 +1084,6 @@ STATIC int INIT inflate(void)
   int e;                /* last block flag */
   int r;                /* result code */
   unsigned h;           /* maximum struct huft's malloc'ed */
-  void *ptr;
 
   /* initialize window, bit buffer */
   wp = 0;
@@ -1057,12 +1095,12 @@ STATIC int INIT inflate(void)
   h = 0;
   do {
     hufts = 0;
-    gzip_mark(&ptr);
-    if ((r = inflate_block(&e)) != 0) {
-      gzip_release(&ptr);	    
+#ifdef ARCH_HAS_DECOMP_WDOG
+    arch_decomp_wdog();
+#endif
+    r = inflate_block(&e);
+    if (r)
 	    return r;
-    }
-    gzip_release(&ptr);
     if (hufts > h)
       h = hufts;
   } while (!e);