cvs commit: src/usr.bin/truss syscalls.c

Marcel Moolenaar marcel at FreeBSD.org
Thu Nov 13 01:04:25 PST 2003


marcel      2003/11/13 01:04:24 PST

  FreeBSD src repository

  Modified files:
    usr.bin/truss        syscalls.c 
  Log:
  Do not ignore any possible errors that fseeko() may have. The fact
  is that fseeko() fails in very predictable and frequent ways on ia64.
  This is because the offset is actually an address in the process'
  address space, which on ia64 can be larger than long (for lseek) or
  off_t (for fseeko). The crux is the signedness. The register stack
  and memory stack are in region 4 on ia64. This means that the sign bit
  is 1. The large positive virtual address is wrongly interpreted as
  a negative file offset.
  
  There's no quick fix. Even if you get around the API by using a
  SEEK_SET up to LONG_MAX and follow it up with a SEEK_CUR for the
  remainder, the kernel simply cannot deal with it. and the second
  seek will just fail.
  
  Therefore, this change does not actually fix the root cause. It just
  makes sure we're not spitting out all kinds of garbage or that the
  get_struct() function in particular does not cause truss(1) to exit.
  This, I might add, invariably happened way too soon for truss(1) to
  be of any use on ia64...
  
  Revision  Changes    Path
  1.33      +24 -22    src/usr.bin/truss/syscalls.c


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