diff mbox

[PING,v2] jump label: fix passing kbuild_cflags when checking for asm goto support

Message ID 20170320171553.GB23333@glebfm.cloud.tilaa.com (mailing list archive)
State New, archived
Headers show

Commit Message

Gleb Fotengauer-Malinovskiy March 20, 2017, 5:15 p.m. UTC
The latest change of asm goto support check added passing of KBUILD_CFLAGS
to compiler.  When these flags reference gcc plugins that are not built yet,
the check fails.

When one runs "make bzImage" followed by "make modules", the kernel is always
built with HAVE_JUMP_LABEL disabled, while the modules are built depending on
CONFIG_JUMP_LABEL.  If HAVE_JUMP_LABEL macro happens to be different, modules
are built with undefined references, e.g.:

ERROR: "static_key_slow_inc" [net/netfilter/xt_TEE.ko] undefined!
ERROR: "static_key_slow_dec" [net/netfilter/xt_TEE.ko] undefined!
ERROR: "static_key_slow_dec" [net/netfilter/nft_meta.ko] undefined!
ERROR: "static_key_slow_inc" [net/netfilter/nft_meta.ko] undefined!
ERROR: "nf_hooks_needed" [net/netfilter/ipvs/ip_vs.ko] undefined!
ERROR: "nf_hooks_needed" [net/ipv6/ipv6.ko] undefined!
ERROR: "static_key_count" [net/ipv6/ipv6.ko] undefined!
ERROR: "static_key_slow_inc" [net/ipv6/ipv6.ko] undefined!

This change moves the check before all these references are added
to KBUILD_CFLAGS.  This is correct because subsequent KBUILD_CFLAGS
modifications are not relevant to this check.

Reported-by: Anton V. Boyarshinov <boyarsh@altlinux.org>
Fixes: 35f860f9ba6a ("jump label: pass kbuild_cflags when checking for asm goto support")
Cc: stable@vger.kernel.org	# v4.10
Signed-off-by: Gleb Fotengauer-Malinovskiy <glebfm@altlinux.org>
Signed-off-by: Dmitry V. Levin <ldv@altlinux.org>
Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Acked-by: David Lin <dtwlin@google.com>
---
v2: update description of the problem fixed by this patch

 Makefile | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

Comments

Masahiro Yamada March 21, 2017, 5:48 p.m. UTC | #1
2017-03-21 2:15 GMT+09:00 Gleb Fotengauer-Malinovskiy <glebfm@altlinux.org>:
> The latest change of asm goto support check added passing of KBUILD_CFLAGS
> to compiler.  When these flags reference gcc plugins that are not built yet,
> the check fails.
>
> When one runs "make bzImage" followed by "make modules", the kernel is always
> built with HAVE_JUMP_LABEL disabled, while the modules are built depending on
> CONFIG_JUMP_LABEL.  If HAVE_JUMP_LABEL macro happens to be different, modules
> are built with undefined references, e.g.:
>
> ERROR: "static_key_slow_inc" [net/netfilter/xt_TEE.ko] undefined!
> ERROR: "static_key_slow_dec" [net/netfilter/xt_TEE.ko] undefined!
> ERROR: "static_key_slow_dec" [net/netfilter/nft_meta.ko] undefined!
> ERROR: "static_key_slow_inc" [net/netfilter/nft_meta.ko] undefined!
> ERROR: "nf_hooks_needed" [net/netfilter/ipvs/ip_vs.ko] undefined!
> ERROR: "nf_hooks_needed" [net/ipv6/ipv6.ko] undefined!
> ERROR: "static_key_count" [net/ipv6/ipv6.ko] undefined!
> ERROR: "static_key_slow_inc" [net/ipv6/ipv6.ko] undefined!
>
> This change moves the check before all these references are added
> to KBUILD_CFLAGS.  This is correct because subsequent KBUILD_CFLAGS
> modifications are not relevant to this check.
>
> Reported-by: Anton V. Boyarshinov <boyarsh@altlinux.org>
> Fixes: 35f860f9ba6a ("jump label: pass kbuild_cflags when checking for asm goto support")
> Cc: stable@vger.kernel.org      # v4.10
> Signed-off-by: Gleb Fotengauer-Malinovskiy <glebfm@altlinux.org>
> Signed-off-by: Dmitry V. Levin <ldv@altlinux.org>
> Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
> Acked-by: David Lin <dtwlin@google.com>
> ---
> v2: update description of the problem fixed by this patch
>


I assume this PING is addressed to me.

First, Steven asked Andrew to pick up this,
but I have not seen it in linux-next yet. So,

Applied to linux-kbuild/fixes.  Thanks!
Steven Rostedt March 21, 2017, 6:04 p.m. UTC | #2
On Wed, 22 Mar 2017 02:48:44 +0900
Masahiro Yamada <yamada.masahiro@socionext.com> wrote:

> 
> I assume this PING is addressed to me.
> 
> First, Steven asked Andrew to pick up this,
> but I have not seen it in linux-next yet. So,
> 
> Applied to linux-kbuild/fixes.  Thanks!

Thanks Masahiro!

-- Steve
--
To unsubscribe from this list: send the line "unsubscribe linux-kbuild" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
diff mbox

Patch

diff --git a/Makefile b/Makefile
index 165cf97..7e3aade 100644
--- a/Makefile
+++ b/Makefile
@@ -653,6 +653,12 @@  KBUILD_CFLAGS += $(call cc-ifversion, -lt, 0409, \
 # Tell gcc to never replace conditional load with a non-conditional one
 KBUILD_CFLAGS	+= $(call cc-option,--param=allow-store-data-races=0)
 
+# check for 'asm goto'
+ifeq ($(shell $(CONFIG_SHELL) $(srctree)/scripts/gcc-goto.sh $(CC) $(KBUILD_CFLAGS)), y)
+	KBUILD_CFLAGS += -DCC_HAVE_ASM_GOTO
+	KBUILD_AFLAGS += -DCC_HAVE_ASM_GOTO
+endif
+
 include scripts/Makefile.gcc-plugins
 
 ifdef CONFIG_READABLE_ASM
@@ -798,12 +804,6 @@  KBUILD_CFLAGS   += $(call cc-option,-Werror=incompatible-pointer-types)
 # use the deterministic mode of AR if available
 KBUILD_ARFLAGS := $(call ar-option,D)
 
-# check for 'asm goto'
-ifeq ($(shell $(CONFIG_SHELL) $(srctree)/scripts/gcc-goto.sh $(CC) $(KBUILD_CFLAGS)), y)
-	KBUILD_CFLAGS += -DCC_HAVE_ASM_GOTO
-	KBUILD_AFLAGS += -DCC_HAVE_ASM_GOTO
-endif
-
 include scripts/Makefile.kasan
 include scripts/Makefile.extrawarn
 include scripts/Makefile.ubsan