[v2,3/6] gzip: remove custom memory allocator

Commit Message

Daniel P. Smith April 17, 2024, 2:37 p.m. UTC

All the other decompression routines use xmalloc_bytes(), thus there is no
reason for gzip to be handling its own allocation of memory. In fact, there is
a bug somewhere in the allocator as decompression started to break when adding
additional allocations. Instead of troubleshooting the allocator, replace it
with xmalloc_bytes().

Signed-off-by: Daniel P. Smith <[e-mail]>
---
 xen/common/gzip/gunzip.c  | 17 ++------------
 xen/common/gzip/inflate.c | 47 ---------------------------------------
 2 files changed, 2 insertions(+), 62 deletions(-)

Comments

Andrew Cooper April 17, 2024, 4:52 p.m. UTC | #1

On 17/04/2024 3:37 pm, Daniel P. Smith wrote:
> All the other decompression routines use xmalloc_bytes(), thus there is no
> reason for gzip to be handling its own allocation of memory. In fact, there is
> a bug somewhere in the allocator as decompression started to break when adding
> additional allocations. Instead of troubleshooting the allocator, replace it
> with xmalloc_bytes().
>
> Signed-off-by: Daniel P. Smith <[e-mail]>
> ---
>  xen/common/gzip/gunzip.c  | 17 ++------------
>  xen/common/gzip/inflate.c | 47 ---------------------------------------
>  2 files changed, 2 insertions(+), 62 deletions(-)

Good riddance.

Reviewed-by: Andrew Cooper <[e-mail]>

Patch

diff --git a/xen/common/gzip/gunzip.c b/xen/common/gzip/gunzip.c
index 1bcb007395ba..1b448d6e3655 100644
--- a/xen/common/gzip/gunzip.c
+++ b/xen/common/gzip/gunzip.c
@@ -4,12 +4,7 @@ 
 #include <xen/lib.h>
 #include <xen/mm.h>
 
-#define HEAPORDER 3
-
 static unsigned char *__initdata window;
-#define memptr long
-static memptr __initdata free_mem_ptr;
-static memptr __initdata free_mem_end_ptr;
 
 #define WSIZE           0x80000000U
 
@@ -24,6 +19,8 @@  static unsigned int __initdata outcnt;
 
 #define OF(args)        args
 
+#define malloc(a)       xmalloc_bytes(a)
+#define free(a)         xfree(a)
 #define memzero(s, n)   memset((s), 0, (n))
 
 typedef unsigned char   uch;
@@ -108,14 +105,6 @@  __init int perform_gunzip(char *output, char *image, unsigned long image_len)
         return 1;
 
     window = (unsigned char *)output;
-
-    free_mem_ptr = (unsigned long)alloc_xenheap_pages(HEAPORDER, 0);
-    if ( !free_mem_ptr )
-        return -ENOMEM;
-
-    free_mem_end_ptr = free_mem_ptr + (PAGE_SIZE << HEAPORDER);
-    init_allocator();
-
     inbuf = (unsigned char *)image;
     insize = image_len;
     inptr = 0;
@@ -132,8 +121,6 @@  __init int perform_gunzip(char *output, char *image, unsigned long image_len)
         rc = 0;
     }
 
-    free_xenheap_pages((void *)free_mem_ptr, HEAPORDER);
-
     return rc;
 }
 
diff --git a/xen/common/gzip/inflate.c b/xen/common/gzip/inflate.c
index 73ccfc2bdc6c..512d9bf0ee2e 100644
--- a/xen/common/gzip/inflate.c
+++ b/xen/common/gzip/inflate.c
@@ -228,53 +228,6 @@  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 __initdata malloc_ptr;
-static int __initdata malloc_count;
-
-static void __init init_allocator(void)
-{
-    malloc_ptr = free_mem_ptr;
-    malloc_count = 0;
-}
-
-static void *__init 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 __init 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.
  * The fastest way to decode is to simply build a lookup table whose