kconfig: let 'shell' return enough output for deep path names

BugLink: https://bugs.launchpad.net/bugs/1963890
[ Upstream commit 8a4c5b2a6d8ea079fa36034e8167de87ab6f8880 ]

The 'shell' built-in only returns the first 256 bytes of the command's
output. In some cases, 'shell' is used to return a path; by bumping up
the buffer size to 4096 this lets us capture up to PATH_MAX.

The specific case where I ran into this was due to commit 1e860048c53e
("gcc-plugins: simplify GCC plugin-dev capability test"). After this
change, we now use `$(shell,$(CC) -print-file-name=plugin)` to return
a path; if the gcc path is particularly long, then the path ends up
truncated at the 256 byte mark, which makes the HAVE_GCC_PLUGINS
depends test always fail.

Signed-off-by: Brenda Streiff <brenda.streiff@ni.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Paolo Pisati <paolo.pisati@canonical.com>

diff --git a/scripts/kconfig/preprocess.c b/scripts/kconfig/preprocess.c
index 0590f86df6e40cfd073100904f3ec5cfbe650f5f..748da578b418c4acb53f454e17e2370d2050ceb6 100644 (file)
--- a/scripts/kconfig/preprocess.c
+++ b/scripts/kconfig/preprocess.c
@@ -141,7 +141,7 @@ static char *do_lineno(int argc, char *argv[])
 static char *do_shell(int argc, char *argv[])
 {
        FILE *p;
-       char buf[256];
+       char buf[4096];
        char *cmd;
        size_t nread;
        int i;