[PATCH 2/3] perf arm64: Generate system call table from asm/unistd.h

[PATCH 2/3] perf arm64: Generate system call table from asm/unistd.h

[Kim Phillips]

This should speed up accessing new system calls introduced with the
kernel rather than waiting for libaudit updates to include them.

Using the existing other arch scripts resulted in this error:

tools/perf/arch/arm64/entry/syscalls//mksyscalltbl: 25: printf: __NR3264_ftruncate: expected numeric value

because, unlike other arches, asm-generic's unistd.h does things like:

 #define __NR_ftruncate __NR3264_ftruncate

Turning the scripts printf's %d into a %s resulted in this in the
generated syscalls.c file:

    static const char *syscalltbl_arm64[] = {
            [__NR3264_ftruncate] = "ftruncate",

So we use the host C compiler to fold the macros, and print them out
from within a temporary C program, in order to get the correct output:

    static const char *syscalltbl_arm64[] = {
            [46] = "ftruncate",

Cc: Ravi Bangoria <ravi.bangoria@linux.vnet.ibm.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Thomas Richter <tmricht@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Kim Phillips <kim.phillips@arm.com>
---
 tools/perf/arch/arm64/Makefile                | 21 ++++++++
 .../arch/arm64/entry/syscalls/mksyscalltbl    | 54 +++++++++++++++++++
 2 files changed, 75 insertions(+)
 create mode 100755 tools/perf/arch/arm64/entry/syscalls/mksyscalltbl

diff --git a/tools/perf/arch/arm64/Makefile b/tools/perf/arch/arm64/Makefile
index 91de4860faad..85fdf4949db3 100644
--- a/tools/perf/arch/arm64/Makefile
+++ b/tools/perf/arch/arm64/Makefile
@@ -4,3 +4,24 @@ PERF_HAVE_DWARF_REGS := 1
 endif
 PERF_HAVE_JITDUMP := 1
 PERF_HAVE_ARCH_REGS_QUERY_REGISTER_OFFSET := 1
+
+#
+# Syscall table generation for perf
+#
+
+out    := $(OUTPUT)arch/arm64/include/generated/asm
+header := $(out)/syscalls.c
+sysdef := $(srctree)/tools/arch/arm64/include/uapi/asm/unistd.h
+sysprf := $(srctree)/tools/perf/arch/arm64/entry/syscalls/
+systbl := $(sysprf)/mksyscalltbl
+
+# Create output directory if not already present
+_dummy := $(shell [ -d '$(out)' ] || mkdir -p '$(out)')
+
+$(header): $(sysdef) $(systbl)
+	$(Q)$(SHELL) '$(systbl)' '$(CC)' '$(HOSTCC)' $(sysdef) > $@
+
+clean::
+	$(call QUIET_CLEAN, arm64) $(RM) $(header)
+
+archheaders: $(header)
diff --git a/tools/perf/arch/arm64/entry/syscalls/mksyscalltbl b/tools/perf/arch/arm64/entry/syscalls/mksyscalltbl
new file mode 100755
index 000000000000..1148302b7194
--- /dev/null
+++ b/tools/perf/arch/arm64/entry/syscalls/mksyscalltbl
@@ -0,0 +1,54 @@
+#!/bin/sh
+# SPDX-License-Identifier: GPL-2.0
+#
+# Generate system call table for perf. Derived from
+# powerpc script.
+#
+# Copyright IBM Corp. 2017
+# Author(s):  Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
+# Changed by: Ravi Bangoria <ravi.bangoria@linux.vnet.ibm.com>
+# Changed by: Kim Phillips <kim.phillips@arm.com>
+
+gcc=$1
+hostcc=$2
+input=$3
+
+if ! test -r $input; then
+	echo "Could not read input file" >&2
+	exit 1
+fi
+
+create_table_from_c()
+{
+	local last_sc
+
+	create_table_base=`mktemp -u /tmp/create-table-XXX`
+	echo "#include <stdio.h>" > ${create_table_base}.c
+	echo "#include \"$input\"" >> ${create_table_base}.c
+
+	echo "int main(int argc, char *argv[])" >> ${create_table_base}.c
+	echo "{" >> ${create_table_base}.c
+	while read sc nr; do
+		echo "	printf(\"\\\t[%d] = \\\"$sc\\\",\\\n\", __NR_$sc);" >> ${create_table_base}.c
+		last_sc=$sc
+	done
+	echo "	printf(\"#define SYSCALLTBL_ARM64_MAX_ID %d\\\n\", __NR_$last_sc);" >> ${create_table_base}.c
+	echo "}" >> ${create_table_base}.c
+
+	$hostcc -o ${create_table_base}.x ${create_table_base}.c
+	${create_table_base}.x
+}
+
+create_table()
+{
+	echo "static const char *syscalltbl_arm64[] = {"
+	create_table_from_c
+	echo '};'
+
+	$RM -f ${create_table_base}.[cx]
+}
+
+$gcc -E -dM -x c  $input	       \
+	|sed -ne 's/^#define __NR_//p' \
+	|sort -t' ' -k2 -nu	       \
+	|create_table
-- 
2.17.1

Re: [PATCH 2/3] perf arm64: Generate system call table from asm/unistd.h

[Hendrik Brueckner]

Hi Kim,

On Tue, Jul 03, 2018 at 12:32:28PM -0500, Kim Phillips wrote:
> This should speed up accessing new system calls introduced with the
> kernel rather than waiting for libaudit updates to include them.
> 
> Using the existing other arch scripts resulted in this error:
> 
> tools/perf/arch/arm64/entry/syscalls//mksyscalltbl: 25: printf: __NR3264_ftruncate: expected numeric value
> 
> because, unlike other arches, asm-generic's unistd.h does things like:
> 
>  #define __NR_ftruncate __NR3264_ftruncate
> 
> Turning the scripts printf's %d into a %s resulted in this in the
> generated syscalls.c file:
> 
>     static const char *syscalltbl_arm64[] = {
>             [__NR3264_ftruncate] = "ftruncate",
> 
> So we use the host C compiler to fold the macros, and print them out
> from within a temporary C program, in order to get the correct output:
> 
>     static const char *syscalltbl_arm64[] = {
>             [46] = "ftruncate",
> 
> Cc: Ravi Bangoria <ravi.bangoria@linux.vnet.ibm.com>
> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
> Cc: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
> Cc: Jiri Olsa <jolsa@redhat.com>
> Cc: Michael Ellerman <mpe@ellerman.id.au>
> Cc: Namhyung Kim <namhyung@kernel.org>
> Cc: Thomas Richter <tmricht@linux.vnet.ibm.com>
> Cc: Peter Zijlstra <peterz@infradead.org>
> Cc: Ingo Molnar <mingo@redhat.com>
> Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
> Signed-off-by: Kim Phillips <kim.phillips@arm.com>
> ---
>  tools/perf/arch/arm64/Makefile                | 21 ++++++++
>  .../arch/arm64/entry/syscalls/mksyscalltbl    | 54 +++++++++++++++++++
>  2 files changed, 75 insertions(+)
>  create mode 100755 tools/perf/arch/arm64/entry/syscalls/mksyscalltbl
> 
> diff --git a/tools/perf/arch/arm64/Makefile b/tools/perf/arch/arm64/Makefile
> index 91de4860faad..85fdf4949db3 100644
> --- a/tools/perf/arch/arm64/Makefile
> +++ b/tools/perf/arch/arm64/Makefile
> @@ -4,3 +4,24 @@ PERF_HAVE_DWARF_REGS := 1
>  endif
>  PERF_HAVE_JITDUMP := 1
>  PERF_HAVE_ARCH_REGS_QUERY_REGISTER_OFFSET := 1
> +
> +#
> +# Syscall table generation for perf
> +#
> +
> +out    := $(OUTPUT)arch/arm64/include/generated/asm
> +header := $(out)/syscalls.c
> +sysdef := $(srctree)/tools/arch/arm64/include/uapi/asm/unistd.h
> +sysprf := $(srctree)/tools/perf/arch/arm64/entry/syscalls/
> +systbl := $(sysprf)/mksyscalltbl
> +
> +# Create output directory if not already present
> +_dummy := $(shell [ -d '$(out)' ] || mkdir -p '$(out)')
> +
> +$(header): $(sysdef) $(systbl)
> +	$(Q)$(SHELL) '$(systbl)' '$(CC)' '$(HOSTCC)' $(sysdef) > $@
> +
> +clean::
> +	$(call QUIET_CLEAN, arm64) $(RM) $(header)
> +
> +archheaders: $(header)
> diff --git a/tools/perf/arch/arm64/entry/syscalls/mksyscalltbl b/tools/perf/arch/arm64/entry/syscalls/mksyscalltbl
> new file mode 100755
> index 000000000000..1148302b7194
> --- /dev/null
> +++ b/tools/perf/arch/arm64/entry/syscalls/mksyscalltbl
> @@ -0,0 +1,54 @@
> +#!/bin/sh
> +# SPDX-License-Identifier: GPL-2.0
> +#
> +# Generate system call table for perf. Derived from
> +# powerpc script.
> +#
> +# Copyright IBM Corp. 2017
> +# Author(s):  Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
> +# Changed by: Ravi Bangoria <ravi.bangoria@linux.vnet.ibm.com>
> +# Changed by: Kim Phillips <kim.phillips@arm.com>
> +
> +gcc=$1
> +hostcc=$2
> +input=$3
> +
> +if ! test -r $input; then
> +	echo "Could not read input file" >&2
> +	exit 1
> +fi
> +
> +create_table_from_c()
> +{
> +	local last_sc

For the sake of completion, also add the "sc" and "nr" local variables.

> +
> +	create_table_base=`mktemp -u /tmp/create-table-XXX`

- The -u is considered to be unsafe. But from below, I think you require
  this for the .c/.x file.  Alternatively, you could create the file
  (and prefer using more X for the template) and append to it.  Or pipe
  the C code to the $hostcc command, e.g.,
	$hostcc -o $create_table_base -x c -
  which would require a single temp file that would be overwritten by gcc.

> +	echo "#include <stdio.h>" > ${create_table_base}.c
> +	echo "#include \"$input\"" >> ${create_table_base}.c
> +
> +	echo "int main(int argc, char *argv[])" >> ${create_table_base}.c
> +	echo "{" >> ${create_table_base}.c

As alternative to these echos, use

cat >> ${create_table_base}.c <<-EoHEADER
	#include <stdio.h>
	#include "$input"
	int main(int argc, char *argv[])
	{
EoHeader

which is at least for larger portions a bit more readable.

> +	while read sc nr; do
> +		echo "	printf(\"\\\t[%d] = \\\"$sc\\\",\\\n\", __NR_$sc);" >> ${create_table_base}.c
> +		last_sc=$sc
> +	done
> +	echo "	printf(\"#define SYSCALLTBL_ARM64_MAX_ID %d\\\n\", __NR_$last_sc);" >> ${create_table_base}.c
> +	echo "}" >> ${create_table_base}.c
> +
> +	$hostcc -o ${create_table_base}.x ${create_table_base}.c
> +	${create_table_base}.x
> +}
> +
> +create_table()
> +{
> +	echo "static const char *syscalltbl_arm64[] = {"
> +	create_table_from_c
> +	echo '};'
> +
> +	$RM -f ${create_table_base}.[cx]

The $RM is obtained from the (make) environment.  I would prefer using rm here
to be able to run as standalone.

> +}
> +
> +$gcc -E -dM -x c  $input	       \
> +	|sed -ne 's/^#define __NR_//p' \
> +	|sort -t' ' -k2 -nu	       \
> +	|create_table
> -- 
> 2.17.1
> 
Kind regards,
  Hendrik

-- 
Hendrik Brueckner
brueckner@linux.ibm.com           | IBM Deutschland Research & Development GmbH
Linux on z Systems Development    | Schoenaicher Str. 220, 71032 Boeblingen


IBM Deutschland Research & Development GmbH
Vorsitzender des Aufsichtsrats: Martina Koederitz
Geschaeftsfuehrung: Dirk Wittkopp
Sitz der Gesellschaft: Boeblingen
Registergericht: Amtsgericht Stuttgart, HRB 243294