[GHC] #7037: setProgName() crashes when argv[0] == NULL

[GHC]

#7037: setProgName() crashes when argv[0] == NULL
------------------------------+---------------------------------------------
 Reporter:  shachaf           |          Owner:                  
     Type:  bug               |         Status:  new             
 Priority:  normal            |      Component:  Runtime System  
  Version:  7.4.2             |       Keywords:                  
       Os:  Unknown/Multiple  |   Architecture:  Unknown/Multiple
  Failure:  Runtime crash     |       Testcase:                  
Blockedby:                    |       Blocking:                  
  Related:                    |  
------------------------------+---------------------------------------------
 C89 allows {{{argc}}} to be 0, in which case {{{argv[0]}}} is {{{NULL}}}.
 This can happen in practice in Linux+glibc with {{{execve(program, {NULL},
 ...);}}}.

 The RTS assumes that {{{argv[0]}}} always points to a valid string:
 {{{void setProgName(char *argv[]) { char *last_slash; if ( (last_slash =
 (char *) strrchr(argv[0], '/')) != NULL ) { ... } else { ... } }}}}.

 This means that any GHC-compiled program can be made to segfault with
 {{{execl("./ghc-compiled-program", NULL);}}}.

-- 
Ticket URL: <http://hackage.haskell.org/trac/ghc/ticket/7037>
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