[v3,4/8] gzip: move window pointer into gunzip state

Commit Message

Daniel P. Smith April 24, 2024, 4:34 p.m. UTC

Move the window pointer, outcnt/wp, into struct gunzip_data. It was erroneously
labeled as outcnt and then define aliased to wp, this eliminates the aliasing
and only refers to as wp, the window pointer.

Signed-off-by: Daniel P. Smith <[e-mail]>
---
 xen/common/gzip/gunzip.c  | 11 +++++------
 xen/common/gzip/inflate.c | 17 ++++++++---------
 2 files changed, 13 insertions(+), 15 deletions(-)

Comments

Jan Beulich April 29, 2024, 2:08 p.m. UTC | #1

On 24.04.2024 18:34, Daniel P. Smith wrote:
> Move the window pointer, outcnt/wp, into struct gunzip_data. It was erroneously
> labeled as outcnt and then define aliased to wp, this eliminates the aliasing
> and only refers to as wp, the window pointer.
> 
> Signed-off-by: Daniel P. Smith <[e-mail]>

Acked-by: Jan Beulich <[e-mail]>

Patch

diff --git a/xen/common/gzip/gunzip.c b/xen/common/gzip/gunzip.c
index e47f10ae19ad..11bfe45d8222 100644
--- a/xen/common/gzip/gunzip.c
+++ b/xen/common/gzip/gunzip.c
@@ -8,6 +8,8 @@ 
 
 struct gunzip_state {
     unsigned char *window;
+    /* window pointer: */
+    unsigned int wp;
 };
 
 static unsigned char *__initdata inbuf;
@@ -16,9 +18,6 @@  static unsigned int __initdata insize;
 /* Index of next byte to be processed in inbuf: */
 static unsigned int __initdata inptr;
 
-/* Bytes in output buffer: */
-static unsigned int __initdata outcnt;
-
 #define malloc(a)       xmalloc_bytes(a)
 #define free(a)         xfree(a)
 #define memzero(s, n)   memset((s), 0, (n))
@@ -75,15 +74,15 @@  static __init void flush_window(struct gunzip_state *s)
     unsigned char *in, ch;
 
     in = s->window;
-    for ( n = 0; n < outcnt; n++ )
+    for ( n = 0; n < s->wp; n++ )
     {
         ch = *in++;
         c = crc_32_tab[((int)c ^ ch) & 0xff] ^ (c >> 8);
     }
     crc = c;
 
-    bytes_out += (unsigned long)outcnt;
-    outcnt = 0;
+    bytes_out += (unsigned long)s->wp;
+    s->wp = 0;
 }
 
 __init int gzip_check(char *image, unsigned long image_len)
diff --git a/xen/common/gzip/inflate.c b/xen/common/gzip/inflate.c
index 5fa5c039c6d1..78b2f20a97ba 100644
--- a/xen/common/gzip/inflate.c
+++ b/xen/common/gzip/inflate.c
@@ -130,7 +130,6 @@  static char rcsid[] = "#Id: inflate.c,v 0.14 1993/06/10 13:27:04 jloup Exp #";
  * "uch *window;" and then malloc'ed in the latter case.  The definition
  * must be in unzip.h, included above.
  */
-#define wp outcnt
 
 /*
  * Huffman code lookup table entry--this entry is four bytes for machines
@@ -556,7 +555,7 @@  static int __init inflate_codes(
     /* make local copies of globals */
     b = bb;                       /* initialize bit buffer */
     k = bk;
-    w = wp;                       /* initialize window position */
+    w = s->wp;                    /* initialize window position */
 
     /* inflate the coded data */
     ml = mask_bits[bl];           /* precompute masks for speed */
@@ -579,7 +578,7 @@  static int __init inflate_codes(
             Tracevv((stderr, "%c", s->window[w-1]));
             if (w == WSIZE)
             {
-                wp = w;
+                s->wp = w;
                 flush_window(s);
                 w = 0;
             }
@@ -627,7 +626,7 @@  static int __init inflate_codes(
                     } while (--e);
                 if (w == WSIZE)
                 {
-                    wp = w;
+                    s->wp = w;
                     flush_window(s);
                     w = 0;
                 }
@@ -636,7 +635,7 @@  static int __init inflate_codes(
     }
 
     /* restore the globals from the locals */
-    wp = w;                       /* restore global window pointer */
+    s->wp = w;                    /* restore global window pointer */
     bb = b;                       /* restore global bit buffer */
     bk = k;
 
@@ -657,7 +656,7 @@  static int __init inflate_stored(struct gunzip_state *s)
     /* make local copies of globals */
     b = bb;                       /* initialize bit buffer */
     k = bk;
-    w = wp;                       /* initialize window position */
+    w = s->wp;                    /* initialize window position */
 
 
     /* go to byte boundary */
@@ -681,7 +680,7 @@  static int __init inflate_stored(struct gunzip_state *s)
         s->window[w++] = (uch)b;
         if (w == WSIZE)
         {
-            wp = w;
+            s->wp = w;
             flush_window(s);
             w = 0;
         }
@@ -689,7 +688,7 @@  static int __init inflate_stored(struct gunzip_state *s)
     }
 
     /* restore the globals from the locals */
-    wp = w;                       /* restore global window pointer */
+    s->wp = w;                    /* restore global window pointer */
     bb = b;                       /* restore global bit buffer */
     bk = k;
 
@@ -1004,7 +1003,7 @@  static int __init inflate(struct gunzip_state *s)
     int r;                /* result code */
 
     /* initialize window, bit buffer */
-    wp = 0;
+    s->wp = 0;
     bk = 0;
     bb = 0;