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library: Use standard major minor macros

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I'm not sure why you would roll your own macros for major and minor
while the standard includes have these defined. Using our versions
causes two problems:
 - Some systems don't use this format for their minor/major
 - If the kernel proc interface becomes a 64-bit number, like
   dev_t is in the library, then our macro will need to be changed.

autoconf already had the check and as a bonus for anyone that
puts these definitions in sys/mkdev.h it handles that too.

So this is now the standard way of getting a minor/major number out of a
device id. Examining bits/sysmacros.h showed that their defines are
close to what devname.c had, except it can handle 64-bit numbers.

Signed-off-by: Craig Small <csmall@dropbear.xyz>
This commit is contained in:
Craig Small 2022-05-03 20:13:49 +10:00
parent 412f3e8aa4
commit 823b6a3b1a
1 changed files with 15 additions and 19 deletions
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34
proc/devname.c
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@ -38,17 +38,13 @@
* dev_to_tty top, ps
*/
#if 0
#ifdef MAJOR_IN_MKDEV
#include <sys/mkdev.h>
#elif defined MAJOR_IN_SYSMACROS
#include <sys/sysmacros.h>
#define MAJOR_OF(d) ((unsigned)major(d))
#define MINOR_OF(d) ((unsigned)minor(d))
#else
#define MAJOR_OF(d) ( ((unsigned)(d)>>8u) & 0xfffu )
#define MINOR_OF(d) ( ((unsigned)(d)&0xffu) | (((unsigned)(d)&0xfff00000u)>>12u) )
#undef major
#undef minor
#define major <-- do not use -->
#define minor <-- do not use -->
#define major(d) ( ((unsigned)(d)>>8u) & 0xfffu )
#define minor(d) ( ((unsigned)(d)&0xffu) | (((unsigned)(d)&0xfff00000u)>>12u) )
#endif
typedef struct tty_map_node {
@ -139,8 +135,8 @@ static int driver_name(char *restrict const buf, unsigned maj, unsigned min){
if(stat(buf, &sbuf) < 0) return 0;
}
}
if(min != MINOR_OF(sbuf.st_rdev)) return 0;
if(maj != MAJOR_OF(sbuf.st_rdev)) return 0;
if(min != minor(sbuf.st_rdev)) return 0;
if(maj != major(sbuf.st_rdev)) return 0;
return 1;
}
@ -275,8 +271,8 @@ static int guess_name(char *restrict const buf, unsigned maj, unsigned min){
default: return 0;
}
if(stat(buf, &sbuf) < 0) return 0;
if(min != MINOR_OF(sbuf.st_rdev)) return 0;
if(maj != MAJOR_OF(sbuf.st_rdev)) return 0;
if(min != minor(sbuf.st_rdev)) return 0;
if(maj != major(sbuf.st_rdev)) return 0;
return 1;
}
@ -294,8 +290,8 @@ static int link_name(char *restrict const buf, unsigned maj, unsigned min, int p
if(count <= 0 || count >= TTY_NAME_SIZE-1) return 0;
buf[count] = '\0';
if(stat(buf, &sbuf) < 0) return 0;
if(min != MINOR_OF(sbuf.st_rdev)) return 0;
if(maj != MAJOR_OF(sbuf.st_rdev)) return 0;
if(min != minor(sbuf.st_rdev)) return 0;
if(maj != major(sbuf.st_rdev)) return 0;
return 1;
}
@ -334,10 +330,10 @@ unsigned dev_to_tty(char *restrict ret, unsigned chop, dev_t dev_t_dev, int pid,
if( ctty_name(tmp, pid )) goto abbrev;
#endif
if(dev == 0u) goto no_tty;
if(driver_name(tmp, MAJOR_OF(dev), MINOR_OF(dev) )) goto abbrev;
if( link_name(tmp, MAJOR_OF(dev), MINOR_OF(dev), pid, "fd/2" )) goto abbrev;
if( guess_name(tmp, MAJOR_OF(dev), MINOR_OF(dev) )) goto abbrev;
if( link_name(tmp, MAJOR_OF(dev), MINOR_OF(dev), pid, "fd/255")) goto abbrev;
if(driver_name(tmp, major(dev), minor(dev) )) goto abbrev;
if( link_name(tmp, major(dev), minor(dev), pid, "fd/2" )) goto abbrev;
if( guess_name(tmp, major(dev), minor(dev) )) goto abbrev;
if( link_name(tmp, major(dev), minor(dev), pid, "fd/255")) goto abbrev;
// fall through if unable to find a device file
no_tty:
strcpy(ret, chop >= 1 ? "?" : "");