Re: [PATCH] perf arm64: Fix mksyscalltbl, don't lose syscalls due to sort -nu

From: Vincent Whitchurch <vincent.whitchurch@axis.com>
To: Leo Yan <leo.yan@linaro.org>, Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Hans-Peter Nilsson <hp@axis.com>,
	<linux-arm-kernel@lists.infradead.org>,
	<linux-kernel@vger.kernel.org>,
	John Garry <john.garry@huawei.com>, Will Deacon <will@kernel.org>,
	Mathieu Poirier <mathieu.poirier@linaro.org>,
	Peter Zijlstra <peterz@infradead.org>,
	Ingo Molnar <mingo@redhat.com>,
	Mark Rutland <mark.rutland@arm.com>,
	Alexander Shishkin <alexander.shishkin@linux.intel.com>,
	Jiri Olsa <jolsa@redhat.com>, Namhyung Kim <namhyung@kernel.org>,
	Kim Phillips <kim.phillips@arm.com>
Subject: Re: [PATCH] perf arm64: Fix mksyscalltbl, don't lose syscalls due to sort -nu
Date: Fri, 25 Nov 2022 12:53:10 +0100	[thread overview]
Message-ID: <Y4Cspv98j8TqwCqZ@axis.com> (raw)
In-Reply-To: <20201229030933.GC28115@leoy-ThinkPad-X240s>

On Tue, Dec 29, 2020 at 11:09:33AM +0800, Leo Yan wrote:
> On Mon, Dec 28, 2020 at 03:39:41AM +0100, Hans-Peter Nilsson wrote:
> > When using "sort -nu", arm64 syscalls were lost.  That is, the
> > io_setup syscall (number 0) and all but one (typically
> > ftruncate; 64) of the syscalls that are defined symbolically
> > (like "#define __NR_ftruncate __NR3264_ftruncate") at the point
> > where "sort" is applied.
> > 
> > This creation-of-syscalls.c-scheme is, judging from comments,
> > copy-pasted from powerpc, and worked there because at the time,
> > its tools/arch/powerpc/include/uapi/asm/unistd.h had *literals*,
> > like "#define __NR_ftruncate 93".
> > 
> > With sort being numeric and the non-numeric key effectively
> > evaluating to 0, the sort option "-u" means these "duplicates"
> > are removed.  There's no need to remove syscall lines with
> > duplicate numbers for arm64 because there are none, so let's fix
> > that by just losing the "-u".  Having the table numerically
> > sorted on syscall-number for the rest of the syscalls looks
> > nice, so keep the "-n".
> > 
> > Signed-off-by: Hans-Peter Nilsson <hp@axis.com>
> 
> Very good catching!  I tested this patch with the commands:
> 
> $ cd $LINUX_KERN
> $ tools/perf/arch/arm64/entry/syscalls/mksyscalltbl \
>         $ARM64_TOOLCHAIN_PATH/aarch64-linux-gnu-gcc \
>         gcc tools tools/include/uapi/asm-generic/unistd.h
> 
> It gives out complete syscall tables:
> 
> $ diff /tmp/mksyscall_before.txt /tmp/mksyscall_after.txt
> 1a2,4
> > 	[223] = "fadvise64",
> > 	[25] = "fcntl",
> > 	[44] = "fstatfs",
> 2a6,11
> > 	[0] = "io_setup",
> > 	[62] = "lseek",
> > 	[222] = "mmap",
> > 	[71] = "sendfile",
> > 	[43] = "statfs",
> > 	[45] = "truncate",
> 
> Rather than dropping option "-u" for sort command, I googled and read
> the manual of "sort", but cannot find other better method.  So this
> patch looks good for me:
> 
> Reviewed-by: Leo Yan <leo.yan@linaro.org>
> Tested-by: Leo Yan <leo.yan@linaro.org>

It looks like this patch was never applied?  AFAICS it is still needed
on current HEAD and it still applies cleanly.

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