Signed-off-by: Daniel P. Smith <dpsmith@apertussolutions.com>
---
xen/common/gzip/gunzip.c | 11 +++++++----
xen/common/gzip/inflate.c | 12 +++++-------
2 files changed, 12 insertions(+), 11 deletions(-)
diff --git a/xen/common/gzip/gunzip.c b/xen/common/gzip/gunzip.c
index 9b4891731b8b..a1b516b925c9 100644
--- a/xen/common/gzip/gunzip.c
+++ b/xen/common/gzip/gunzip.c
@@ -28,6 +28,9 @@ struct gzip_data {
unsigned long bb; /* bit buffer */
unsigned bk; /* bits in bit buffer */
+
+ unsigned long crc_32_tab[256];
+ unsigned long crc;
};
#define OF(args) args
@@ -78,7 +81,7 @@ static __init void flush_window(struct gzip_data *gd)
* The window is equal to the output buffer therefore only need to
* compute the crc.
*/
- unsigned long c = crc;
+ unsigned long c = gd->crc;
unsigned int n;
unsigned char *in, ch;
@@ -86,9 +89,9 @@ static __init void flush_window(struct gzip_data *gd)
for ( n = 0; n < gd->outcnt; n++ )
{
ch = *in++;
- c = crc_32_tab[((int)c ^ ch) & 0xff] ^ (c >> 8);
+ c = gd->crc_32_tab[((int)c ^ ch) & 0xff] ^ (c >> 8);
}
- crc = c;
+ gd->crc = c;
gd->bytes_out += (unsigned long)gd->outcnt;
gd->outcnt = 0;
@@ -129,7 +132,7 @@ __init int perform_gunzip(char *output, char *image, unsigned long image_len)
gd.inptr = 0;
gd.bytes_out = 0;
- makecrc();
+ makecrc(&gd);
if ( gunzip(&gd) < 0 )
{
diff --git a/xen/common/gzip/inflate.c b/xen/common/gzip/inflate.c
index c8dd35962abb..6c8c7452a31f 100644
--- a/xen/common/gzip/inflate.c
+++ b/xen/common/gzip/inflate.c
@@ -1125,16 +1125,14 @@ static int __init inflate(struct gzip_data *gd)
*
**********************************************************************/
-static ulg __initdata crc_32_tab[256];
-static ulg __initdata crc; /* initialized in makecrc() so it'll reside in bss */
-#define CRC_VALUE (crc ^ 0xffffffffUL)
+#define CRC_VALUE (gd->crc ^ 0xffffffffUL)
/*
* Code to compute the CRC-32 table. Borrowed from
* gzip-1.0.3/makecrc.c.
*/
-static void __init makecrc(void)
+static void __init makecrc(struct gzip_data *gd)
{
/* Not copyrighted 1990 Mark Adler */
@@ -1151,7 +1149,7 @@ static void __init makecrc(void)
for (i = 0; i < sizeof(p)/sizeof(int); i++)
e |= 1L << (31 - p[i]);
- crc_32_tab[0] = 0;
+ gd->crc_32_tab[0] = 0;
for (i = 1; i < 256; i++)
{
@@ -1162,11 +1160,11 @@ static void __init makecrc(void)
if (k & 1)
c ^= e;
}
- crc_32_tab[i] = c;
+ gd->crc_32_tab[i] = c;
}
/* this is initialized here so this code could reside in ROM */
- crc = (ulg)0xffffffffUL; /* shift register contents */
+ gd->crc = (ulg)0xffffffffUL; /* shift register contents */
}
/* gzip flag byte */
--
2.30.2On 11/04/2024 4:25 pm, Daniel P. Smith wrote:
> diff --git a/xen/common/gzip/inflate.c b/xen/common/gzip/inflate.c
> index c8dd35962abb..6c8c7452a31f 100644
> --- a/xen/common/gzip/inflate.c
> +++ b/xen/common/gzip/inflate.c
> @@ -1125,16 +1125,14 @@ static int __init inflate(struct gzip_data *gd)
> *
> **********************************************************************/
>
> -static ulg __initdata crc_32_tab[256];
> -static ulg __initdata crc; /* initialized in makecrc() so it'll reside in bss */
> -#define CRC_VALUE (crc ^ 0xffffffffUL)
> +#define CRC_VALUE (gd->crc ^ 0xffffffffUL)
>
> /*
> * Code to compute the CRC-32 table. Borrowed from
> * gzip-1.0.3/makecrc.c.
> */
>
> -static void __init makecrc(void)
> +static void __init makecrc(struct gzip_data *gd)
> {
> /* Not copyrighted 1990 Mark Adler */
>
> @@ -1151,7 +1149,7 @@ static void __init makecrc(void)
> for (i = 0; i < sizeof(p)/sizeof(int); i++)
> e |= 1L << (31 - p[i]);
>
> - crc_32_tab[0] = 0;
> + gd->crc_32_tab[0] = 0;
>
> for (i = 1; i < 256; i++)
> {
> @@ -1162,11 +1160,11 @@ static void __init makecrc(void)
> if (k & 1)
> c ^= e;
> }
> - crc_32_tab[i] = c;
> + gd->crc_32_tab[i] = c;
> }
>
> /* this is initialized here so this code could reside in ROM */
> - crc = (ulg)0xffffffffUL; /* shift register contents */
> + gd->crc = (ulg)0xffffffffUL; /* shift register contents */
> }
>
> /* gzip flag byte */
I can't see any way that a non-32bit value ever gets stored, because 'e'
doesn't ever have bit 32 set in it. I have a sneaking suspicion that
this is code written in the 32bit days, where sizeof(long) was still 4.
This change, if correct, halves the size of gzip_state.
~Andrew
On 4/11/24 15:43, Andrew Cooper wrote:
> On 11/04/2024 4:25 pm, Daniel P. Smith wrote:
>> diff --git a/xen/common/gzip/inflate.c b/xen/common/gzip/inflate.c
>> index c8dd35962abb..6c8c7452a31f 100644
>> --- a/xen/common/gzip/inflate.c
>> +++ b/xen/common/gzip/inflate.c
>> @@ -1125,16 +1125,14 @@ static int __init inflate(struct gzip_data *gd)
>> *
>> **********************************************************************/
>>
>> -static ulg __initdata crc_32_tab[256];
>> -static ulg __initdata crc; /* initialized in makecrc() so it'll reside in bss */
>> -#define CRC_VALUE (crc ^ 0xffffffffUL)
>> +#define CRC_VALUE (gd->crc ^ 0xffffffffUL)
>>
>> /*
>> * Code to compute the CRC-32 table. Borrowed from
>> * gzip-1.0.3/makecrc.c.
>> */
>>
>> -static void __init makecrc(void)
>> +static void __init makecrc(struct gzip_data *gd)
>> {
>> /* Not copyrighted 1990 Mark Adler */
>>
>> @@ -1151,7 +1149,7 @@ static void __init makecrc(void)
>> for (i = 0; i < sizeof(p)/sizeof(int); i++)
>> e |= 1L << (31 - p[i]);
>>
>> - crc_32_tab[0] = 0;
>> + gd->crc_32_tab[0] = 0;
>>
>> for (i = 1; i < 256; i++)
>> {
>> @@ -1162,11 +1160,11 @@ static void __init makecrc(void)
>> if (k & 1)
>> c ^= e;
>> }
>> - crc_32_tab[i] = c;
>> + gd->crc_32_tab[i] = c;
>> }
>>
>> /* this is initialized here so this code could reside in ROM */
>> - crc = (ulg)0xffffffffUL; /* shift register contents */
>> + gd->crc = (ulg)0xffffffffUL; /* shift register contents */
>> }
>>
>> /* gzip flag byte */
>
> I can't see any way that a non-32bit value ever gets stored, because 'e'
> doesn't ever have bit 32 set in it. I have a sneaking suspicion that
> this is code written in the 32bit days, where sizeof(long) was still 4.
Yes, I can switch crc and crc_32_tab to uint32_t.
> This change, if correct, halves the size of gzip_state.
Ack.
v/r,
dps
© 2016 - 2026 Red Hat, Inc.