On Thu, Apr 17, 2014 at 02:16:31AM -0700, Dima Kogan wrote: > Dmitry V. Levin <[email protected]> writes: > > > On Wed, Apr 16, 2014 at 11:19:06PM -0700, Dima Kogan wrote: > >> Dima Kogan <[email protected]> writes: > >> > Dmitry V. Levin <[email protected]> writes: > >> > > >> OK. Never mind on the llseek, actually. I was testing lseek, NOT llseek, > >> which is why it looked odd. The patch I attached earlier can be fixed > >> with some #ifdefs probably. I should be pretty trivial. Is it useful for > >> me to do it, or do you want to? > > > > If the result is going to be as complex as printllval without alignment, > > it worth extending printllval instead of reinventing the wheel. > > Currently printllval assumes register alignment, which (on ARM at least) > should be done for some syscalls (like pread) but not others (like > preadv). To make printllval work here, it'd need to take an extra > argument to indicate whether alignment should happen or not. That > function is already full of logic, so I was thinking instead something > of printing the preadv/pwritev pos like this: > > #ifdef 64bit > printllval(tcp, "%llu", PREAD_OFFSET_ARG); > #else > tprintf("%llu", LONG_LONG(tcp->u_arg[3], tcp->u_arg[4])); > #endif > > Here "64bit" would be replaced by something that's defined if we can > pass 64-bit args in a single register. I don't know about all the > platforms that printllval() checks, so I can't say if this "64bit" check > would be complicated or not. Looking at printllval(), it looks like it's > possible to have sizeof(long)==8, but still pass syscall args in 32-bit > pieces. Do you know the details about all the cases?
There are platforms that support multiple personalities.
For example, x86 personality on x86_64.
Here is a stripped down printllval, I don't see a simpler way to implement this:
#if SIZEOF_LONG > 4 && SIZEOF_LONG == SIZEOF_LONG_LONG
# if SUPPORTED_PERSONALITIES > 1
if (current_wordsize > 4)
# endif
tprintf(format, tcp->u_arg[arg_no]);
# if SUPPORTED_PERSONALITIES > 1
else
tprintf(format, LONG_LONG(tcp->u_arg[arg_no], tcp->u_arg[arg_no
+ 1]));
# endif /* SUPPORTED_PERSONALITIES */
#elif SIZEOF_LONG > 4
# error Unsupported configuration: SIZEOF_LONG > 4 && SIZEOF_LONG_LONG >
SIZEOF_LONG
#elif defined LINUX_MIPSN32
tprintf(format, tcp->ext_arg[arg_no]);
#elif defined X32
if (current_personality == 0)
tprintf(format, tcp->ext_arg[arg_no]);
else
tprintf(format, LONG_LONG(tcp->u_arg[arg_no], tcp->u_arg[arg_no
+ 1]));
#else
tprintf(format, LONG_LONG(tcp->u_arg[arg_no], tcp->u_arg[arg_no + 1]));
#endif
--
ldv
pgpHfgls0Y_C8.pgp
Description: PGP signature
------------------------------------------------------------------------------ Learn Graph Databases - Download FREE O'Reilly Book "Graph Databases" is the definitive new guide to graph databases and their applications. Written by three acclaimed leaders in the field, this first edition is now available. Download your free book today! http://p.sf.net/sfu/NeoTech
_______________________________________________ Strace-devel mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/strace-devel
