* Re: 64-bit syscall ABI issue [not found] <Pine.LNX.4.64.0706042051280.16431@digraph.polyomino.org.uk> @ 2007-06-04 21:25 ` David Miller 2007-06-05 0:04 ` H. Peter Anvin 0 siblings, 1 reply; 2+ messages in thread From: David Miller @ 2007-06-04 21:25 UTC (permalink / raw) To: joseph; +Cc: linux-kernel, linux-mips, linux-arch From: "Joseph S. Myers" <joseph@codesourcery.com> Date: Mon, 4 Jun 2007 20:56:57 +0000 (UTC) [ added linux-arch which is a great place to discuss these kinds of issues. ] > What should the kernel syscall ABI be in such cases (any case where the > syscall implementations expect arguments narrower than registers, so > mainly 32-bit arguments on 64-bit platforms)? There are two obvious > possibilities: In general we've taken the stance that the syscall dispatch should create the proper calling environment for C code implementing the system calls, and this thus means properly sign and zero extending the arguments as expected by the C calling convention. ^ permalink raw reply [flat|nested] 2+ messages in thread
* Re: 64-bit syscall ABI issue 2007-06-04 21:25 ` 64-bit syscall ABI issue David Miller @ 2007-06-05 0:04 ` H. Peter Anvin 0 siblings, 0 replies; 2+ messages in thread From: H. Peter Anvin @ 2007-06-05 0:04 UTC (permalink / raw) To: David Miller; +Cc: joseph, linux-kernel, linux-mips, linux-arch David Miller wrote: > From: "Joseph S. Myers" <joseph@codesourcery.com> > Date: Mon, 4 Jun 2007 20:56:57 +0000 (UTC) > > [ added linux-arch which is a great place to discuss these > kinds of issues. ] > >> What should the kernel syscall ABI be in such cases (any case where the >> syscall implementations expect arguments narrower than registers, so >> mainly 32-bit arguments on 64-bit platforms)? There are two obvious >> possibilities: > > In general we've taken the stance that the syscall dispatch > should create the proper calling environment for C code > implementing the system calls, and this thus means properly > sign and zero extending the arguments as expected by the C > calling convention. This is, in fact, rather fundamental (some ABIs don't require sign or zero extension, e.g. x86-64); otherwise libc's job becomes a whole lot harder. -hpa ^ permalink raw reply [flat|nested] 2+ messages in thread
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[not found] <Pine.LNX.4.64.0706042051280.16431@digraph.polyomino.org.uk>
2007-06-04 21:25 ` 64-bit syscall ABI issue David Miller
2007-06-05 0:04 ` H. Peter Anvin
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