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Re: [PATCH 07/15] Use semget syscall for Linux implementation
On 01/11/2016 14:40, Joseph Myers wrote:
> On Tue, 1 Nov 2016, Andreas Schwab wrote:
>
>> On Nov 01 2016, Adhemerval Zanella <adhemerval.zanella@linaro.org> wrote:
>>
>>> This patch add a direct call to semget syscall if it is defined by
>>> kernel headers.
>>
>> That does not mean that the running kernel provides it.
>
> Specifically, this sort of patch series needs to be accompanied by an
> analysis of when the relevant syscalls were added for each supported
> architecture (and subarchitecture for cases with multiple syscall tables
> for different ABNs). If present (in the syscall table as well as in
> asm/unistd.h) in the minimum kernel version, OK, otherwise you need
> appropriate __ASSUME_* conditionals (even if not present in the latest
> kernel, it might be added in future, so you should have those conditionals
> now to avoid breaking things when current glibc is compiled with future
> kernel headers).
Indeed, I did not consider the case of latest kernel headers. Based
on current Linux approach and historical implementation for sysv IPC
I think we can assume that either the kernel only supports the old
'ipc' syscall or all the sysvipc syscall wire-up. Do you know if we
do require an __ASSUME for each syscall?