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| author | Michael Olbrich <m.olbrich@pengutronix.de> | 2018-04-12 10:36:54 +0200 |
|---|---|---|
| committer | Denys Vlasenko <vda.linux@googlemail.com> | 2018-04-14 01:55:51 +0200 |
| commit | 43dd0062229170747dcbee0a2a87b8e5ee2f09d6 (patch) | |
| tree | 5b2936d00438b86e327dc56cf025c96a4faa4773 | |
| parent | c783cf78af04e898a20f69f28b885f7c0285020c (diff) | |
| download | busybox-43dd0062229170747dcbee0a2a87b8e5ee2f09d6.tar.gz | |
build system: fix parallel building issue
The files generated by the include/config/MARKER target are in the
dependency list for applets/applet_tables.
If applets/applet_tables is created first during applets_dir then it will
be created again later as part of $(busybox-dirs).
As a result include/applet_tables.h is created again. This time while other
build commands may need it.
Let applets_dir depend on include/config/MARKER to avoid this particular
race condition and create the header files atomically to ensure that the
compiler never sees incomplete files.
Signed-off-by: Michael Olbrich <m.olbrich@pengutronix.de>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
| -rw-r--r-- | Makefile | 2 | ||||
| -rw-r--r-- | applets/applet_tables.c | 16 |
2 files changed, 15 insertions, 3 deletions
@@ -368,7 +368,7 @@ gen_build_files: $(wildcard $(srctree)/*/*.c) $(wildcard $(srctree)/*/*/*.c) # we depend on scripts_basic, since scripts/basic/fixdep # must be built before any other host prog PHONY += applets_dir -applets_dir: scripts_basic gen_build_files +applets_dir: scripts_basic gen_build_files include/config/MARKER $(Q)$(MAKE) $(build)=applets applets/%: applets_dir ; diff --git a/applets/applet_tables.c b/applets/applet_tables.c index ef911a43b..e3d10c83f 100644 --- a/applets/applet_tables.c +++ b/applets/applet_tables.c @@ -10,6 +10,7 @@ #include <sys/types.h> #include <sys/stat.h> #include <fcntl.h> +#include <limits.h> #include <stdlib.h> #include <string.h> #include <stdio.h> @@ -61,6 +62,7 @@ static int str_isalnum_(const char *s) int main(int argc, char **argv) { int i, j; + char tmp1[PATH_MAX], tmp2[PATH_MAX]; // In find_applet_by_name(), before linear search, narrow it down // by looking at N "equidistant" names. With ~350 applets: @@ -84,7 +86,8 @@ int main(int argc, char **argv) if (!argv[1]) return 1; - i = open(argv[1], O_WRONLY | O_TRUNC | O_CREAT, 0666); + snprintf(tmp1, PATH_MAX, "%s.%u.new", argv[1], (int) getpid()); + i = open(tmp1, O_WRONLY | O_TRUNC | O_CREAT, 0666); if (i < 0) return 1; dup2(i, 1); @@ -209,12 +212,21 @@ int main(int argc, char **argv) // fclose(fp); // } // if (strcmp(line_old, line_new) != 0) { - fp = fopen(argv[2], "w"); + snprintf(tmp2, PATH_MAX, "%s.%u.new", argv[2], (int) getpid()); + fp = fopen(tmp2, "w"); if (!fp) return 1; fputs(line_new, fp); + if (fclose(fp)) + return 1; // } } + if (fclose(stdout)) + return 1; + if (rename(tmp1, argv[1])) + return 1; + if (rename(tmp2, argv[2])) + return 1; return 0; } |