Hi everyone,
I made the changes Alan asked for to my patch for i386/dmi_scan.
This patch applies to the Linux 2.2 tree and has been built against
2.2.22. I will port it to 2.4 and 2.5 once accepted for 2.2.
Features:
- Ensure that dmi_string always return a null-terminated string.
- Fix an off-by-one error causing the last entry of the DMI table
not to be decoded.
- Stop skipping DMI entries when type is less than those of the
previous entry.
- Ensure we don't run off the table in dmi_table. Call dmi_decode only
if the whole entry (formated area and strings) fits in the table.
- Verify the DMI entry point structure checksum.
- Start looking for the DMI entry point from 0xF0000, not 0xE0000.
- Fix an off-by-one error causing the last address scanned to be
0x100000, not 0xFFFF0 as it should.
- Do not display the DMI version if it would be 0.0.
- Remove now senseless tests in dump (debug) code.
Other changes are simple cleanups and should be straightforward to
understand.
Some numbers:
source code: +216 bytes
binary w/o debug: +108 bytes
binary w/ debug: -44 bytes
All comments are of course welcome.
--- linux-2.2.22/arch/i386/kernel/dmi_scan.c.orig Sun Mar 25 18:37:29 2001
+++ linux-2.2.22/arch/i386/kernel/dmi_scan.c Mon Oct 7 09:23:22 2002
@@ -15,9 +15,11 @@
static char * __init dmi_string(struct dmi_header *dm, u8 s)
{
u8 *bp=(u8 *)dm;
+ if(!s)
+ return "";
bp+=dm->length;
s--;
- while(s>0)
+ while(s>0 && *bp)
{
bp+=strlen(bp);
bp++;
@@ -31,24 +33,26 @@
u8 *buf;
struct dmi_header *dm;
u8 *data;
- int i=1;
- int last = 0;
+ int i=0;
buf = ioremap(base, len);
if(buf==NULL)
return -1;
data = buf;
- while(i<num && (data-buf) < len)
+ while(i<num && data-buf+sizeof(struct dmi_header)<=len)
{
dm=(struct dmi_header *)data;
- if(dm->type < last)
- break;
- last = dm->type;
- decode(dm);
+ /*
+ * We want to know the total length (formated area and strings)
+ * before decoding to make sure we won't run off the table in
+ * dmi_decode or dmi_string
+ */
data+=dm->length;
- while(*data || data[1])
+ while(data-buf<len-1 && (data[0] || data[1]))
data++;
+ if(data-buf<len-1)
+ decode(dm);
data+=2;
i++;
}
@@ -57,33 +61,48 @@
}
+inline int __init dmi_checksum(u8 *buf)
+{
+ u8 sum=0;
+ int a;
+
+ for(a=0; a<15; a++)
+ sum+=buf[a];
+ return (sum==0);
+}
+
int __init dmi_iterate(void (*decode)(struct dmi_header *))
{
- unsigned char buf[20];
- long fp=0xE0000L;
- fp -= 16;
+ u8 buf[15];
+ u32 fp=0xF0000;
while( fp < 0xFFFFF)
{
- fp+=16;
- memcpy_fromio(buf, fp, 20);
- if(memcmp(buf, "_DMI_", 5)==0)
+ memcpy_fromio(buf, fp, 15);
+ if(memcmp(buf, "_DMI_", 5)==0 && dmi_checksum(buf))
{
u16 num=buf[13]<<8|buf[12];
u16 len=buf[7]<<8|buf[6];
u32 base=buf[11]<<24|buf[10]<<16|buf[9]<<8|buf[8];
#ifdef DUMP_DMI
- printk(KERN_INFO "DMI %d.%d present.\n",
- buf[14]>>4, buf[14]&0x0F);
+ /*
+ * DMI version 0.0 means that the real version is taken from
+ * the SMBIOS version, which we don't know at this point.
+ */
+ if(buf[14]!=0)
+ printk(KERN_INFO "DMI %u.%u present.\n",
+ buf[14]>>4, buf[14]&0x0F);
+ else
+ printk(KERN_INFO "DMI present.\n");
printk(KERN_INFO "%d structures occupying %d bytes.\n",
- buf[13]<<8|buf[12],
- buf[7]<<8|buf[6]);
+ num, len);
printk(KERN_INFO "DMI table at 0x%08X.\n",
- buf[11]<<24|buf[10]<<16|buf[9]<<8|buf[8]);
+ base);
#endif
if(dmi_table(base,len, num, decode)==0)
return 0;
}
+ fp+=16;
}
return -1;
}
@@ -98,21 +117,17 @@
static void __init dmi_decode(struct dmi_header *dm)
{
u8 *data = (u8 *)dm;
- char *p;
switch(dm->type)
{
case 0:
#ifdef DUMP_DMI
- p=dmi_string(dm,data[4]);
- if(*p && *p!=' ')
- {
- printk("BIOS Vendor: %s\n", p);
- printk("BIOS Version: %s\n",
- dmi_string(dm, data[5]));
- printk("BIOS Release: %s\n",
- dmi_string(dm, data[8]));
- }
+ printk("BIOS Vendor: %s\n",
+ dmi_string(dm, data[4]));
+ printk("BIOS Version: %s\n",
+ dmi_string(dm, data[5]));
+ printk("BIOS Release: %s\n",
+ dmi_string(dm, data[8]));
#endif
/*
* Check for clue free BIOS implementations who use
@@ -142,35 +157,22 @@
break;
#ifdef DUMP_DMI
case 1:
- p=dmi_string(dm,data[4]);
-
- if(*p && *p!=' ')
- {
- printk("System Vendor: %s.\n",p);
- printk("Product Name: %s.\n",
- dmi_string(dm, data[5]));
- printk("Version %s.\n",
- dmi_string(dm, data[6]));
- printk("Serial Number %s.\n",
- dmi_string(dm, data[7]));
- }
+ printk("System Vendor: %s\n",
+ dmi_string(dm, data[4]));
+ printk("Product Name: %s\n",
+ dmi_string(dm, data[5]));
+ printk("Version: %s\n",
+ dmi_string(dm, data[6]));
+ printk("Serial Number: %s\n",
+ dmi_string(dm, data[7]));
break;
case 2:
- p=dmi_string(dm,data[4]);
-
- if(*p && *p!=' ')
- {
- printk("Board Vendor: %s.\n",p);
- printk("Board Name: %s.\n",
+ printk("Board Vendor: %s\n",
+ dmi_string(dm, data[4]));
+ printk("Board Name: %s\n",
dmi_string(dm, data[5]));
- printk("Board Version: %s.\n",
- dmi_string(dm, data[6]));
- }
- break;
- case 3:
- p=dmi_string(dm,data[8]);
- if(*p && *p!=' ')
- printk("Asset Tag: %s.\n", p);
+ printk("Board Version: %s\n",
+ dmi_string(dm, data[6]));
break;
#endif
}
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