From 47346e96f004eca07720e1e2b24fc7f0b0df4092 Mon Sep 17 00:00:00 2001 From: Masahiro Yamada Date: Tue, 24 Sep 2019 21:07:40 +0900 Subject: modpost: fix static EXPORT_SYMBOL warnings for UML build Johannes Berg reports lots of modpost warnings on ARCH=um builds: WARNING: "rename" [vmlinux] is a static EXPORT_SYMBOL WARNING: "lseek" [vmlinux] is a static EXPORT_SYMBOL WARNING: "ftruncate64" [vmlinux] is a static EXPORT_SYMBOL WARNING: "getuid" [vmlinux] is a static EXPORT_SYMBOL WARNING: "lseek64" [vmlinux] is a static EXPORT_SYMBOL WARNING: "unlink" [vmlinux] is a static EXPORT_SYMBOL WARNING: "pwrite64" [vmlinux] is a static EXPORT_SYMBOL WARNING: "close" [vmlinux] is a static EXPORT_SYMBOL WARNING: "opendir" [vmlinux] is a static EXPORT_SYMBOL WARNING: "pread64" [vmlinux] is a static EXPORT_SYMBOL WARNING: "syscall" [vmlinux] is a static EXPORT_SYMBOL WARNING: "readdir" [vmlinux] is a static EXPORT_SYMBOL WARNING: "readdir64" [vmlinux] is a static EXPORT_SYMBOL WARNING: "futimes" [vmlinux] is a static EXPORT_SYMBOL WARNING: "__lxstat" [vmlinux] is a static EXPORT_SYMBOL WARNING: "write" [vmlinux] is a static EXPORT_SYMBOL WARNING: "closedir" [vmlinux] is a static EXPORT_SYMBOL WARNING: "__xstat" [vmlinux] is a static EXPORT_SYMBOL WARNING: "fsync" [vmlinux] is a static EXPORT_SYMBOL WARNING: "__lxstat64" [vmlinux] is a static EXPORT_SYMBOL WARNING: "__fxstat64" [vmlinux] is a static EXPORT_SYMBOL WARNING: "telldir" [vmlinux] is a static EXPORT_SYMBOL WARNING: "printf" [vmlinux] is a static EXPORT_SYMBOL WARNING: "readlink" [vmlinux] is a static EXPORT_SYMBOL WARNING: "__sprintf_chk" [vmlinux] is a static EXPORT_SYMBOL WARNING: "link" [vmlinux] is a static EXPORT_SYMBOL WARNING: "rmdir" [vmlinux] is a static EXPORT_SYMBOL WARNING: "fdatasync" [vmlinux] is a static EXPORT_SYMBOL WARNING: "truncate" [vmlinux] is a static EXPORT_SYMBOL WARNING: "statfs" [vmlinux] is a static EXPORT_SYMBOL WARNING: "__errno_location" [vmlinux] is a static EXPORT_SYMBOL WARNING: "__xmknod" [vmlinux] is a static EXPORT_SYMBOL WARNING: "open64" [vmlinux] is a static EXPORT_SYMBOL WARNING: "truncate64" [vmlinux] is a static EXPORT_SYMBOL WARNING: "open" [vmlinux] is a static EXPORT_SYMBOL WARNING: "read" [vmlinux] is a static EXPORT_SYMBOL WARNING: "chown" [vmlinux] is a static EXPORT_SYMBOL WARNING: "chmod" [vmlinux] is a static EXPORT_SYMBOL WARNING: "utime" [vmlinux] is a static EXPORT_SYMBOL WARNING: "fchmod" [vmlinux] is a static EXPORT_SYMBOL WARNING: "seekdir" [vmlinux] is a static EXPORT_SYMBOL WARNING: "ioctl" [vmlinux] is a static EXPORT_SYMBOL WARNING: "dup2" [vmlinux] is a static EXPORT_SYMBOL WARNING: "statfs64" [vmlinux] is a static EXPORT_SYMBOL WARNING: "utimes" [vmlinux] is a static EXPORT_SYMBOL WARNING: "mkdir" [vmlinux] is a static EXPORT_SYMBOL WARNING: "fchown" [vmlinux] is a static EXPORT_SYMBOL WARNING: "__guard" [vmlinux] is a static EXPORT_SYMBOL WARNING: "symlink" [vmlinux] is a static EXPORT_SYMBOL WARNING: "access" [vmlinux] is a static EXPORT_SYMBOL WARNING: "__stack_smash_handler" [vmlinux] is a static EXPORT_SYMBOL When you run "make", the modpost is run twice; before linking vmlinux, and before building modules. All the warnings above are from the second modpost. The offending symbols are defined not in vmlinux, but in the C library. The first modpost is run against the relocatable vmlinux.o, and those warnings are nicely suppressed because the SH_UNDEF entries from the symbol table clear the ->is_static flag. The second modpost is run against the executable vmlinux (+ modules), where those symbols have been resolved, but the definitions do not exist. This commit fixes it in a straightforward way; suppress the static EXPORT_SYMBOL warnings from "vmlinux". Without this commit, we see valid warnings twice anyway. For example, ARCH=arm64 defconfig shows the following warning twice: WARNING: "HYPERVISOR_platform_op" [vmlinux] is a static EXPORT_SYMBOL_GPL So, it is reasonable to suppress the second one. Fixes: 15bfc2348d54 ("modpost: check for static EXPORT_SYMBOL* functions") Reported-by: Johannes Berg Signed-off-by: Masahiro Yamada Tested-by: Johannes Berg Tested-by: Denis Efremov --- scripts/mod/modpost.c | 13 +++++++++---- 1 file changed, 9 insertions(+), 4 deletions(-) (limited to 'scripts') diff --git a/scripts/mod/modpost.c b/scripts/mod/modpost.c index 3961941e8e7a..442d5e2ad688 100644 --- a/scripts/mod/modpost.c +++ b/scripts/mod/modpost.c @@ -2652,15 +2652,20 @@ int main(int argc, char **argv) fatal("modpost: Section mismatches detected.\n" "Set CONFIG_SECTION_MISMATCH_WARN_ONLY=y to allow them.\n"); for (n = 0; n < SYMBOL_HASH_SIZE; n++) { - struct symbol *s = symbolhash[n]; + struct symbol *s; + + for (s = symbolhash[n]; s; s = s->next) { + /* + * Do not check "vmlinux". This avoids the same warnings + * shown twice, and false-positives for ARCH=um. + */ + if (is_vmlinux(s->module->name) && !s->module->is_dot_o) + continue; - while (s) { if (s->is_static) warn("\"%s\" [%s] is a static %s\n", s->name, s->module->name, export_str(s->export)); - - s = s->next; } } -- cgit v1.2.3