kbuild: Use ls(1) instead of stat(1) to obtain file size
authorMichael Forney <forney@google.com>
Mon, 19 Mar 2018 00:54:02 +0000 (17:54 -0700)
committerMasahiro Yamada <yamada.masahiro@socionext.com>
Sun, 25 Mar 2018 17:01:24 +0000 (02:01 +0900)
stat(1) is not standardized and different implementations have their own
(conflicting) flags for querying the size of a file.

ls(1) provides the same information (value of st.st_size) in the 5th
column, except when the file is a character or block device. This output
is standardized[0]. The -n option turns on -l, which writes lines
formatted like

  "%s %u %s %s %u %s %s\n", <file mode>, <number of links>,
      <owner name>, <group name>, <size>, <date and time>,
      <pathname>

but instead of writing the <owner name> and <group name>, it writes the
numeric owner and group IDs (this avoids /etc/passwd and /etc/group
lookups as well as potential field splitting issues).

The <size> field is specified as "the value that would be returned for
the file in the st_size field of struct stat".

To avoid duplicating logic in several locations in the tree, create
scripts/file-size.sh and update callers to use that instead of stat(1).

[0] http://pubs.opengroup.org/onlinepubs/9699919799/utilities/ls.html#tag_20_73_10

Signed-off-by: Michael Forney <forney@google.com>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
arch/arm/boot/deflate_xip_data.sh
arch/powerpc/boot/wrapper
scripts/Makefile.lib
scripts/file-size.sh [new file with mode: 0755]
scripts/link-vmlinux.sh

index 1189598..07adfc7 100755 (executable)
@@ -45,7 +45,7 @@ data_start=$(($__data_loc - $base_offset))
 data_end=$(($_edata_loc - $base_offset))
 
 # Make sure data occupies the last part of the file.
-file_end=$(stat -c "%s" "$XIPIMAGE")
+file_end=$(${CONFIG_SHELL} "${srctree}/scripts/file-size.sh" "$XIPIMAGE")
 if [ "$file_end" != "$data_end" ]; then
        printf "end of xipImage doesn't match with _edata_loc (%#x vs %#x)\n" \
               $(($file_end + $base_offset)) $_edata_loc 2>&1
index 76fe3cc..f9141ea 100755 (executable)
@@ -355,7 +355,7 @@ vmz="$tmpdir/`basename \"$kernel\"`.$ext"
 
 # Calculate the vmlinux.strip size
 ${CROSS}objcopy $objflags "$kernel" "$vmz.$$"
-strip_size=$(stat -c %s $vmz.$$)
+strip_size=$(${CONFIG_SHELL} "${srctree}/scripts/file-size.sh" "$vmz.$$")
 
 if [ -z "$cacheit" -o ! -f "$vmz$compression" -o "$vmz$compression" -ot "$kernel" ]; then
     # recompress the image if we need to
index 5fd60af..ef592e9 100644 (file)
@@ -329,7 +329,7 @@ dtc-tmp = $(subst $(comma),_,$(dot-target).dts.tmp)
 size_append = printf $(shell                                           \
 dec_size=0;                                                            \
 for F in $1; do                                                                \
-       fsize=$$(stat -c "%s" $$F);                                     \
+       fsize=$$($(CONFIG_SHELL) $(srctree)/scripts/file-size.sh $$F);  \
        dec_size=$$(expr $$dec_size + $$fsize);                         \
 done;                                                                  \
 printf "%08x\n" $$dec_size |                                           \
diff --git a/scripts/file-size.sh b/scripts/file-size.sh
new file mode 100755 (executable)
index 0000000..7eb7423
--- /dev/null
@@ -0,0 +1,4 @@
+#!/bin/sh
+# SPDX-License-Identifier: GPL-2.0
+set -- $(ls -dn "$1")
+printf '%s\n' "$5"
index 08ca08e..9045823 100755 (executable)
@@ -269,8 +269,8 @@ if [ -n "${CONFIG_KALLSYMS}" ]; then
        kallsyms .tmp_vmlinux2 .tmp_kallsyms2.o
 
        # step 3
-       size1=$(stat -c "%s" .tmp_kallsyms1.o)
-       size2=$(stat -c "%s" .tmp_kallsyms2.o)
+       size1=$(${CONFIG_SHELL} "${srctree}/scripts/file-size.sh" .tmp_kallsyms1.o)
+       size2=$(${CONFIG_SHELL} "${srctree}/scripts/file-size.sh" .tmp_kallsyms2.o)
 
        if [ $size1 -ne $size2 ] || [ -n "${KALLSYMS_EXTRA_PASS}" ]; then
                kallsymso=.tmp_kallsyms3.o