Here is the architecture-dependent part of the patch. It's worth noting
that the current supported architectures are x86, PPC and PPC64. I
intend to submit a patch for x86_64 ASAP.

Regards,

-- 
Sérgio Durigan Júnior
Linux on Power Toolchain - Software Engineer
Linux Technology Center - LTC
IBM Brazil

gdb/ChangeLog:

2009-01-25  Sergio Durigan Junior <sergiodj@linux.vnet.ibm.com>

	* i386-linux-nat.c (i386_linux_resume): Select the proper request
	to be made for ptrace() considering if we are catching syscalls
	or not.
	* i386-linux-tdep.c: Include linux-tdep.h header, define the XML
	syscall name for the architecture.
	(i386_linux_get_syscall_number): New.
	(i386_linux_init_abi): Call linux_tdep_init to initialize common
	functions.  Register the correct functions for syscall catchpoint.
	* linux-nat.c: Define some helpful variables to track wether we have
	support for the needed ptrace() option.
	(linux_test_for_tracesysgood): New.
	(linux_supports_tracesysgood): New.
	(linux_enable_tracesysgood): New.
	(linux_passed_by_entrypoint): New.
	(linux_enable_event_reporting): Save the current used ptrace()
	options.
	(linux_child_set_syscall_catchpoint): New function.
	(linux_child_post_startup_inferior): Create the entry breakpoint.
	(linux_child_insert_syscall_catchpoint): New.
	(linux_child_remove_syscall_catchpoint): New.
	(linux_nat_create_inferior): Properly set the flag which indicates
	if the inferior have already passed through its entrypoint.
	(linux_handle_extended_wait): Handle the case which the inferior stops
	because it has called or returned from a syscall.
	(linux_nat_filter_event): Likewise.
	(linux_target_install_ops): Install the necessary functions to handle
	syscall catchpoints and entry breakpoints.
	* linux-nat.h (struct lwp_info): Include syscall_state into the
	structure, which indicates if we are in a syscall entry or return.
	* linux-tdep.c: New file.
	(init_sysinfo): New function.
	(linux_get_syscall_by_number): Likewise.
	(linux_get_syscall_by_name): Likewise.
	(linux_get_syscall_names): Likewise.
	(linux_tdep_init): Likewise.
	* linux-tdep.h: New file.
	* ppc-linux-tdep.c: Include linux-tdep.h header, define the XML
	syscall filename for the arch.
	(ppc_linux_get_syscall_number): New.
	(ppc_linux_init_abi): Call linux_tdep_init to initialize common
	functions.  Register the correct functions for syscall catchpoint.