Note that negative system call numbers no longer appear negative in

ktrace output, due to range-bounding by binary masking.
This commit is contained in:
nathanw 2001-06-04 20:06:41 +00:00
parent 859a6a49b2
commit 4b2dbe7a1a

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@ -1,4 +1,4 @@
$NetBSD: README.mach-traps,v 1.2 1999/03/23 09:19:25 itohy Exp $
$NetBSD: README.mach-traps,v 1.3 2001/06/04 20:06:41 nathanw Exp $
Some Alpha AXP OSF/1 binaries directly use the facilities provided by
the Mach kernel that is the basis for OSF/1. These include (but are
@ -9,6 +9,12 @@ with an "unimplemented system call" trap (SIGSYS signal) for a syscall
that has a negative number. In general, binaries that use the Mach
syscalls appear to invoke task_self() as their first syscall.
Note that system call numbers are now range-bounded by masking off the
high bits, so negative system call numbers will appear in the high
end of the system call number range, thanks to the wonders of two's
compliment arithmetic. System call -10, for example, will appear as
"CALL [502]" in kdump output.
The name, number, and number of arguments for each Mach syscall is
given below; this information was gleaned by looking through the OSF/1
libmach.a's object files with dbx, then double-checked against the