RE: [PATCH] arm64: fix /proc/cpuinfo for elf32

From: Zengtao (B)
Date: Tue Apr 26 2016 - 22:13:59 EST


> -----Original Message-----
> From: Suzuki K Poulose [mailto:Suzuki.Poulose@xxxxxxx]
> Sent: Tuesday, April 26, 2016 5:21 PM
> To: Zengtao (B); Catalin Marinas
> Cc: will.deacon@xxxxxxx; mark.rutland@xxxxxxx; yang.shi@xxxxxxxxxx;
> linux-kernel@xxxxxxxxxxxxxxx; james.morse@xxxxxxx;
> linux-arm-kernel@xxxxxxxxxxxxxxxxxxx
> Subject: Re: [PATCH] arm64: fix /proc/cpuinfo for elf32
>
> On 26/04/16 03:21, Zengtao (B) wrote:
> >
> > So you mean the 64-bit grep should see the same cpuinfo as its father process
> > which is 32-bit?
> >
> > For 32-bit process running on 64-bit kernel, we have to explicitly call the
> personality
> > syscall to get the right cpuinfo, but how to deal with the old 32-bit binaries?
>
> Yes, you could use the syscall to switch the personality. Alternately, you could
> run
> "linux32" command to switch the personality to PER_LINUX32 and then
> execute
> 64/32 bit applications.
>

Any plan to place the personality syscall in libc? It is not nessary for each 32-bit process
to do the personality syscall or linux32 command.

> Suzuki
>
>