Re: [PATCH V2] perf arm64: Fix generate system call table failed with /tmp mounted with noexec

[Arnaldo Carvalho de Melo <acme@redhat.com>]

Em Fri, Oct 19, 2018 at 11:22:38AM -0400, Sébastien Boisvert escreveu:
> 
> 
> On 2018-10-18 10:16 p.m., Hongxu Jia wrote:
> > When /tmp is mounted with noexec, mksyscalltbl fails.
> > [snip]
> > |perf-1.0/tools/perf/arch/arm64/entry/syscalls//mksyscalltbl:
> > /tmp/create-table-6VGPSt: Permission denied
> > [snip]
> > 
> > Add variable TMPDIR as prefix dir of the temporary file, if it is set,
> > replace default /tmp
> > 
> > Remove extra slash from `syscalls//mksyscalltbl'
> > 
> > Fixes: 2b5882435606 ("perf arm64: Generate system call table from asm/unistd.h")
> > 
> > Signed-off-by: Hongxu Jia <hongxu.jia@windriver.com>
> > ---
> >  tools/perf/arch/arm64/Makefile                    | 2 +-
> >  tools/perf/arch/arm64/entry/syscalls/mksyscalltbl | 2 +-
> >  2 files changed, 2 insertions(+), 2 deletions(-)
> > 
> > diff --git a/tools/perf/arch/arm64/Makefile b/tools/perf/arch/arm64/Makefile
> > index dbef716..bc2a284 100644
> > --- a/tools/perf/arch/arm64/Makefile
> > +++ b/tools/perf/arch/arm64/Makefile
> > @@ -13,7 +13,7 @@ out    := $(OUTPUT)arch/arm64/include/generated/asm
> >  header := $(out)/syscalls.c
> >  incpath := $(srctree)/tools
> >  sysdef := $(srctree)/tools/arch/arm64/include/uapi/asm/unistd.h
> > -sysprf := $(srctree)/tools/perf/arch/arm64/entry/syscalls/
> > +sysprf := $(srctree)/tools/perf/arch/arm64/entry/syscalls
> 
> Should this appear in different patch, since it is unrelated to adding TMPDIR support ?

Exactly.

So, to move forward, just send a new patch specifically for this part,
i.e. the removal of the harmless but unneeded extra slash, the other
part I already took care of.

- Arnaldo
 
> Thanks
> 
> >  systbl := $(sysprf)/mksyscalltbl
> >  
> >  # Create output directory if not already present
> > diff --git a/tools/perf/arch/arm64/entry/syscalls/mksyscalltbl b/tools/perf/arch/arm64/entry/syscalls/mksyscalltbl
> > index 2dbb8cad..c88fd32 100755
> > --- a/tools/perf/arch/arm64/entry/syscalls/mksyscalltbl
> > +++ b/tools/perf/arch/arm64/entry/syscalls/mksyscalltbl
> > @@ -23,7 +23,7 @@ create_table_from_c()
> >  {
> >  	local sc nr last_sc
> >  
> > -	create_table_exe=`mktemp /tmp/create-table-XXXXXX`
> > +	create_table_exe=`mktemp ${TMPDIR:-/tmp}/create-table-XXXXXX`
> >  
> >  	{
> >  
> >