bin/127276: [patch] ldd(1) invokes linux yes

[Dominic Fandrey]

The following reply was made to PR bin/127276; it has been noted by GNATS.

From: Dominic Fandrey <kamikaze at bsdforen.de>
To: bug-followup at FreeBSD.org, kamikaze at bsdforen.de
Cc:  
Subject: Re: bin/127276: [patch] ldd(1) invokes linux yes
Date: Thu, 13 Jan 2011 11:44:06 +0100

 I tested the patch, prior to the test:
 
 > ldd /compat/linux/usr/bin/yes
 y
 y
 y
 y
 y
 y
 ...
 
 After I applied the patch:
 > ldd /compat/linux/usr/bin/yes
 /compat/linux/usr/bin/yes:
 	libc.so.6 => /lib/libc.so.6 (0x28075000)
 	/lib/ld-linux.so.2 (0x2804f000)
 
 Apparently it returns libraries from the /compat/linux perspective.
 
 > ldd /compat/linux/lib/ld-linux.so.2
 ldd: /compat/linux/lib/ld-linux.so.2: not a FreeBSD ELF shared object
 
 The behaviour caused by the patch is comprehensible and a vast
 improvement over the old behaviour in my opinion, so I'm all for
 it.
 
 At some point the manual page of ldd should be updated to describe
 the new behaviour. If the patch is committed, I volunteer to make
 the changes.
 
 Because the patch was mangled by Gnats, I resubmit it here. I did
 not make any changes apart from the header to trigger the usual
 patch detection magic.
 
 Regards
 
 diff -u ldd.c.old ldd.c
 --- ldd.c.old	2009-09-19 21:45:17.000000000 +0900
 +++ ldd.c	2010-05-04 11:48:42.000000000 +0900
 @@ -65,7 +65,7 @@
  #endif
  
  static int	is_executable(const char *fname, int fd, int *is_shlib,
 -		    int *type);
 +			      int *osabi, int *type);
  static void	usage(void);
  
  #define	TYPE_UNKNOWN	0
 @@ -177,14 +177,14 @@
  
  	rval = 0;
  	for (; argc > 0; argc--, argv++) {
 -		int fd, status, is_shlib, rv, type;
 +		int fd, status, is_shlib, rv, type, osabi;
  
  		if ((fd = open(*argv, O_RDONLY, 0)) < 0) {
  			warn("%s", *argv);
  			rval |= 1;
  			continue;
  		}
 -		rv = is_executable(*argv, fd, &is_shlib, &type);
 +		rv = is_executable(*argv, fd, &is_shlib, &osabi, &type);
  		close(fd);
  		if (rv == 0) {
  			rval |= 1;
 @@ -197,6 +197,8 @@
  			break;
  #if __ELF_WORD_SIZE > 32 && defined(ELF32_SUPPORTED)
  		case TYPE_ELF32:
 +			if (osabi != ELFOSABI_FREEBSD)
 +				break;
  			rval |= execldd32(*argv, fmt1, fmt2, aflag, vflag);
  			continue;
  #endif
 @@ -267,7 +269,7 @@
  }
  
  static int
 -is_executable(const char *fname, int fd, int *is_shlib, int *type)
 +is_executable(const char *fname, int fd, int *is_shlib, int *osabi, int *type)
  {
  	union {
  		struct exec aout;
 @@ -300,6 +302,8 @@
  		return (1);
  	}
  
 +	*osabi = hdr.elf.e_ident[EI_OSABI];
 +
  #if __ELF_WORD_SIZE > 32 && defined(ELF32_SUPPORTED)
  	if ((size_t)n >= sizeof(hdr.elf32) && IS_ELF(hdr.elf32) &&
  	    hdr.elf32.e_ident[EI_CLASS] == ELFCLASS32) {