[libc-dev] Linux powerpc new system call instruction and ABI
Nicholas Piggin via libc-dev
libc-dev at lists.llvm.org
Wed May 19 00:55:35 PDT 2021
Excerpts from Joakim Tjernlund's message of May 19, 2021 5:33 pm:
> On Wed, 2021-05-19 at 02:13 +0300, Dmitry V. Levin wrote:
>> On Thu, Jun 11, 2020 at 06:12:01PM +1000, Nicholas Piggin wrote:
>> > - Error handling: The consensus among kernel, glibc, and musl is to move to
>> > using negative return values in r3 rather than CR0[SO]=1 to indicate error,
>> > which matches most other architectures, and is closer to a function call.
> What about syscalls like times(2) which can return -1 without it being an error?
They do become errors / indistinguishable and have to be dealt with by
libc or userspace. Which does follow what most architectures do (all
except ia64, mips, sparc, and powerpc actually).
Interesting question though, it should have been noted.
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