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Date: Mon, 25 Jan 2021 22:33:15 +0300
From: Alexey Izbyshev <izbyshev@ispras.ru>
To: musl@lists.openwall.com
Cc: Bruno Haible <bruno@clisp.org>
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Subject: Re: [musl] insufficient checking in
 posix_spawn_file_actions_add{open,dup2}

On 2021-01-25 19:15, Rich Felker wrote:
> On Mon, Jan 25, 2021 at 05:07:36PM +0100, Bruno Haible wrote:
>> Do you know why even simple syscalls like getpid()
>> exist in the vdso only for ia64?
> 
> In the case of getpid, because glibc does (or at least did? not sure
> if they still do) cache it themselves in the TCB, adding it to vdso
> offered no additional concrete benefit.
> 
Glibc dropped PID caching long ago[1], and it famously regressed systemd 
at the time[2].

[1] 
https://sourceware.org/git/?p=glibc.git;a=commit;h=c579f48edba88380635ab98cb612030e3ed8691e
[2] https://bugzilla.redhat.com/show_bug.cgi?id=1469670

Alexey