| Message ID | 20170726133655.2137437-1-arnd@arndb.de (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
Hi Arnd, This patch was picked up for linux-next (I assume it was queued up for 4.14-rc1) but I see this warning in Linus' tree. If we are not comfortable with this warning in the 4.13 release, shall I include this patch in the kbuild/fixes pull request? (planned this week) Please let me know your thought. 2017-07-26 22:36 GMT+09:00 Arnd Bergmann <arnd@arndb.de>: > A previous patch added the --no-wchar-size-warning to the Makefile to > avoid this harmless warning: "A previous patch" sounds ambiguous. The previous patch was applied one year ago. If it is OK, I can reword like Commit 971a69db7dc0 ("Xen: don't warn about 2-byte wchar_t in efi") added ... > arm-linux-gnueabi-ld: warning: drivers/xen/efi.o uses 2-byte wchar_t yet the output is to use 4-byte wchar_t; use of wchar_t values across objects may fail > > Changing kbuild to use thin archives instead of recursive linking > unfortunately brings the same warning back during the final link. > > The kernel does not use wchar_t string literals at this point, and > xen does not use wchar_t at all (only efi_char16_t), so the flag > has no effect, but as pointed out by Jan Beulich, adding a wchar_t > string literal would be bad here. > > Since wchar_t is always defined as u16, independent of the toolchain > default, always passing -fshort-wchar is correct and lets us > remove the Xen specific hack along with fixing the warning. > > Signed-off-by: Arnd Bergmann <arnd@arndb.de> > Fixes: 971a69db7dc0 ("Xen: don't warn about 2-byte wchar_t in efi") > Acked-by: David Vrabel <david.vrabel@citrix.com> > Link: https://patchwork.kernel.org/patch/9275217/ > --- > I submitted an earlier patch in August 2016, simply removing the > flag in xen, but there seems to be no harm in enabling it globally > --- > Makefile | 2 +- > drivers/xen/Makefile | 3 --- > 2 files changed, 1 insertion(+), 4 deletions(-) > > diff --git a/Makefile b/Makefile > index f1533423094f..0fe63a47fd52 100644 > --- a/Makefile > +++ b/Makefile > @@ -396,7 +396,7 @@ LINUXINCLUDE := \ > KBUILD_CPPFLAGS := -D__KERNEL__ > > KBUILD_CFLAGS := -Wall -Wundef -Wstrict-prototypes -Wno-trigraphs \ > - -fno-strict-aliasing -fno-common \ > + -fno-strict-aliasing -fno-common -fshort-wchar \ > -Werror-implicit-function-declaration \ > -Wno-format-security \ > -std=gnu89 $(call cc-option,-fno-PIE) > diff --git a/drivers/xen/Makefile b/drivers/xen/Makefile > index 8feab810aed9..7f188b8d0c67 100644 > --- a/drivers/xen/Makefile > +++ b/drivers/xen/Makefile > @@ -7,9 +7,6 @@ obj-y += xenbus/ > nostackp := $(call cc-option, -fno-stack-protector) > CFLAGS_features.o := $(nostackp) > > -CFLAGS_efi.o += -fshort-wchar > -LDFLAGS += $(call ld-option, --no-wchar-size-warning) > - > dom0-$(CONFIG_ARM64) += arm-device.o > dom0-$(CONFIG_PCI) += pci.o > dom0-$(CONFIG_USB_SUPPORT) += dbgp.o > -- > 2.9.0 >
On Sun, Aug 20, 2017 at 2:31 PM, Masahiro Yamada <yamada.masahiro@socionext.com> wrote: > Hi Arnd, > > This patch was picked up for linux-next > (I assume it was queued up for 4.14-rc1) > but I see this warning in Linus' tree. > > If we are not comfortable with this warning in the 4.13 release, > shall I include this patch in the kbuild/fixes pull request? > (planned this week) > > Please let me know your thought. Yes, I think it would be good to have in 4.13, since it's a regression against older kernels. > 2017-07-26 22:36 GMT+09:00 Arnd Bergmann <arnd@arndb.de>: >> A previous patch added the --no-wchar-size-warning to the Makefile to >> avoid this harmless warning: > > "A previous patch" sounds ambiguous. > > The previous patch was applied one year ago. > > > If it is OK, I can reword like > > Commit 971a69db7dc0 ("Xen: don't warn about 2-byte wchar_t in efi") added ... Good idea, thanks! Arnd -- 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
2017-08-21 4:22 GMT+09:00 Arnd Bergmann <arnd@arndb.de>: > On Sun, Aug 20, 2017 at 2:31 PM, Masahiro Yamada > <yamada.masahiro@socionext.com> wrote: >> Hi Arnd, >> >> This patch was picked up for linux-next >> (I assume it was queued up for 4.14-rc1) >> but I see this warning in Linus' tree. >> >> If we are not comfortable with this warning in the 4.13 release, >> shall I include this patch in the kbuild/fixes pull request? >> (planned this week) >> >> Please let me know your thought. > > Yes, I think it would be good to have in 4.13, since it's a regression > against older kernels. > >> 2017-07-26 22:36 GMT+09:00 Arnd Bergmann <arnd@arndb.de>: >>> A previous patch added the --no-wchar-size-warning to the Makefile to >>> avoid this harmless warning: >> >> "A previous patch" sounds ambiguous. >> >> The previous patch was applied one year ago. >> >> >> If it is OK, I can reword like >> >> Commit 971a69db7dc0 ("Xen: don't warn about 2-byte wchar_t in efi") added ... > > Good idea, thanks! > Applied to linux-kbuild/fixes. Thanks!
diff --git a/Makefile b/Makefile index f1533423094f..0fe63a47fd52 100644 --- a/Makefile +++ b/Makefile @@ -396,7 +396,7 @@ LINUXINCLUDE := \ KBUILD_CPPFLAGS := -D__KERNEL__ KBUILD_CFLAGS := -Wall -Wundef -Wstrict-prototypes -Wno-trigraphs \ - -fno-strict-aliasing -fno-common \ + -fno-strict-aliasing -fno-common -fshort-wchar \ -Werror-implicit-function-declaration \ -Wno-format-security \ -std=gnu89 $(call cc-option,-fno-PIE) diff --git a/drivers/xen/Makefile b/drivers/xen/Makefile index 8feab810aed9..7f188b8d0c67 100644 --- a/drivers/xen/Makefile +++ b/drivers/xen/Makefile @@ -7,9 +7,6 @@ obj-y += xenbus/ nostackp := $(call cc-option, -fno-stack-protector) CFLAGS_features.o := $(nostackp) -CFLAGS_efi.o += -fshort-wchar -LDFLAGS += $(call ld-option, --no-wchar-size-warning) - dom0-$(CONFIG_ARM64) += arm-device.o dom0-$(CONFIG_PCI) += pci.o dom0-$(CONFIG_USB_SUPPORT) += dbgp.o