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perf arm64: Simplify mksyscalltbl

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This patch isn't intended to have any effect on the compiled code.  It
just removes one level of indirection: calling the *host* compiler to
build and then run a program that just printf:s the numerical entries of
the syscall-table.  In other words, the generated syscalls.c changes
from:

	[46] = "ftruncate",
to:
	[__NR3264_ftruncate] = "ftruncate",

The latter is as good as the former to the user of perf, and this can be
done directly by the shell-script.  The syscalls defined as non-literal
values (like "#define __NR_ftruncate __NR3264_ftruncate") are trivially
resolved at compile-time without namespace-leaking and/or collision for
its sole user, perf/util/syscalltbl.c, that just #includes the generated
file.  A future "-mabi=32" support would probably have to handle this
differently, but that is a pre-existing problem not affected by this
simplification.

Calling the *host* compiler only complicates things and accidentally can
get a completely wrong set of files and syscall numbers, see earlier
commits.  Note that the script parameter hostcc is now unused.

At the time of this patch, powerpc (the origin, see comments), and also
e.g. x86 has moved on, from filtering "gcc -dM -E" output to reading
separate specific text-file, a table of syscall numbers.  IMHO should
arm64 consider adopting this.

Signed-off-by: Hans-Peter Nilsson <hp@axis.com>

Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Reviewed-by: Leo Yan <leo.yan@linaro.org>
Tested-by: Leo Yan <leo.yan@linaro.org>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: John Garry <john.garry@huawei.com>
Cc: Kim Phillips <kim.phillips@arm.com>
Cc: Leo Yan <leo.yan@linaro.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will@kernel.org>
Cc: linux-arm-kernel@lists.infradead.org
Link: https://lore.kernel.org/r/20201228024159.2BB66203B5@pchp3.se.axis.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
This commit is contained in:
Hans-Peter Nilsson 2020-12-28 03:41:59 +01:00 committed by Arnaldo Carvalho de Melo
parent c3c2e8ebe3
commit 9854e7ad35
1 changed files with 3 additions and 20 deletions
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23
tools/perf/arch/arm64/entry/syscalls/mksyscalltbl
View file

@ -23,34 +23,17 @@ create_table_from_c()
{
local sc nr last_sc
create_table_exe=`mktemp ${TMPDIR:-/tmp}/create-table-XXXXXX`
{
cat <<-_EoHEADER
#include <stdio.h>
#include "$input"
int main(int argc, char *argv[])
{
_EoHEADER
while read sc nr; do
printf "%s\n" " printf(\"\\t[%d] = \\\"$sc\\\",\\n\", __NR_$sc);"
printf "%s\n" " [$nr] = \"$sc\","
last_sc=$sc
done
printf "%s\n" " printf(\"#define SYSCALLTBL_ARM64_MAX_ID %d\\n\", __NR_$last_sc);"
printf "}\n"
} | $hostcc -I $incpath/include/uapi -o $create_table_exe -x c -
$create_table_exe
rm -f $create_table_exe
printf "%s\n" "#define SYSCALLTBL_ARM64_MAX_ID __NR_$last_sc"
}
create_table()
{
echo "#include \"$input\""
echo "static const char *syscalltbl_arm64[] = {"
create_table_from_c
echo "};"