Hello,
I've been working lately with on how to port valgrind to GNU/Hurd, and found out
that this is not a trivial task. Seems like one have to make a suitable mix of
linux and darwin code (and to some extent freebsd/solaris code). Being a novice
on assembly programming I need some help on modifying the Darwin code for
syscall-x86-darwin.S to GNU. The following code snippet fails to compile with
gcc/gas:
#define VKI_SIG_SETMASK 3
/* DO_SYSCALL MACH|MDEP|UNIX */
#define MACH 1
#define MDEP 2
#define UNIX 3
.macro DO_SYSCALL
/* establish stack frame */
push %ebp
mov %esp, %ebp
subl $$8, %esp /* 16-byte align stack */
L_$0_1: /* Even though we can't take a signal until the
__pthread_sigmask completes, start the range early.
If eip is in the range [1,2), the syscall hasn't been started yet */
/* Set the signal mask which should be current during the syscall. */
/* Set up for __pthread_sigmask(SIG_SETMASK, sysmask, postmask) */
pushl 20(%ebp)
pushl 16(%ebp)
pushl $$VKI_SIG_SETMASK
pushl $$0xcafebabe /* totally fake return address */
movl $$__NR___pthread_sigmask, %eax
int $$0x80 /* should be sysenter? */
jc L_$0_7 /* __pthread_sigmask failed */
addl $$16,%esp
....
L_$0_2:
.if $0 == UNIX
int $$0x80 /* UNIX (GrP fixme should be sysenter?) */
.elseif $0 == MACH
int $$0x81
.elseif $0 == MDEP
int $$0x82
.else
error$0 x
.endif
L_ $0_3: ...
.endm (.endmacro gives: Error: unexpected end of file in macro `do_syscall'
definition)
.globl ML_(do_syscall_for_client_unix_WRK)
ML_(do_syscall_for_client_unix_WRK):
DO_SYSCALL UNIX
(additional code for DO_SYSCALL MACH/MDEP)
.data
#define FOO(scclass,labelno) L_##scclass##_##labelno
#define MK_L_SCCLASS_N(scclass,labelno) FOO(scclass,labelno)
.globl ML_(blksys_setup_UNIX)
.globl ML_(blksys_restart_UNIX)
.globl ML_(blksys_complete_UNIX)
.globl ML_(blksys_committed_UNIX)
.globl ML_(blksys_finished_UNIX)
ML_(blksys_setup_UNIX): .long MK_L_SCCLASS_N(UNIX,1)
ML_(blksys_restart_UNIX): .long MK_L_SCCLASS_N(UNIX,2)
ML_(blksys_complete_UNIX): .long MK_L_SCCLASS_N(UNIX,3)
ML_(blksys_committed_UNIX): .long MK_L_SCCLASS_N(UNIX,4)
ML_(blksys_finished_UNIX): .long MK_L_SCCLASS_N(UNIX,5)
(additional code for MACH/MDEP)
Compiling results in:
m_syswrap/syscall-x86-gnu.S:196: Error: too many positional arguments (3 times)
How to change the macro definition to accept aruments?
Is the code OK also for GNU/Hurd?
Thanks!
