From: "Maciej W. Rozycki" <macro@linux-mips.org>
To: Arnd Bergmann <arnd@arndb.de>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>,
Kees Cook <keescook@chromium.org>,
linux-arch <linux-arch@vger.kernel.org>,
linux-kbuild <linux-kbuild@vger.kernel.org>,
LKML <linux-kernel@vger.kernel.org>,
"linux-arm-kernel@lists.infradead.org"
<linux-arm-kernel@lists.infradead.org>,
Russell King <rmk+kernel@armlinux.org.uk>,
Andrew Morton <akpm@linux-foundation.org>,
kernel-build-reports@lists.linaro.org,
kvmarm@lists.cs.columbia.edu
Subject: Re: [RFC] minimum gcc version for kernel: raise to gcc-4.3 or 4.6?
Date: Mon, 24 Apr 2017 19:30:09 +0100 (BST) [thread overview]
Message-ID: <alpine.LFD.2.20.1704241908260.32200@eddie.linux-mips.org> (raw)
Message-ID: <20170424183009.Fa4yB8ISAMjUIGb2xiTmiZNNFeEur401cQ8mtm2wRjk@z> (raw)
In-Reply-To: <CAK8P3a03BTEBgz87k_dhJuqzOYQm_S5FFDrFgcBAE5FCH-e=dQ@mail.gmail.com>
On Mon, 24 Apr 2017, Arnd Bergmann wrote:
> I later tried all mips defconfigs with linux-4.3 and they all failed
> with gcc-4.1.3
> but built fine with gcc-4.9. I've now tried decstation_defconfig in 4.8-rc11,
> and this is what I see for gcc-4.1.3
>
> make O=build/mips/decstation_defconfig/ -skj30
> CC=/home/arnd/cross-gcc/bin/mips-linux-gcc-4.1.3\ ARCH=mips -f
> Makefile CROSS_COMPILE=/home/arnd/cross-gcc/bin/mips-linux-
> /git/arm-soc/fs/dcache.c: In function '__d_move':
> /git/arm-soc/fs/dcache.c:2773: warning: 'n' may be used uninitialized
> in this function
> /git/arm-soc/fs/dcache.c: In function 'd_splice_alias':
> /git/arm-soc/fs/dcache.c:2529: warning: 'n' may be used uninitialized
> in this function
> /git/arm-soc/fs/dcache.c: In function 'd_add':
> /git/arm-soc/fs/dcache.c:2529: warning: 'n' may be used uninitialized
> in this function
> /git/arm-soc/mm/page-writeback.c: In function 'balance_dirty_pages_ratelimited':
> /git/arm-soc/mm/page-writeback.c:1627: warning: 'writeback' is used
> uninitialized in this function
> /git/arm-soc/mm/page-writeback.c:1628: warning: 'filepages' is used
> uninitialized in this function
> /git/arm-soc/mm/page-writeback.c:1628: warning: 'headroom' is used
> uninitialized in this function
> /git/arm-soc/mm/page-writeback.c: In function 'wb_over_bg_thresh':
> /git/arm-soc/mm/page-writeback.c:1956: warning: 'filepages' is used
> uninitialized in this function
> /git/arm-soc/mm/page-writeback.c:1956: warning: 'headroom' is used
> uninitialized in this function
> /git/arm-soc/net/core/flow_dissector.c: In function '__skb_flow_dissect':
> /git/arm-soc/net/core/flow_dissector.c:272: warning: 'vlan' may be
> used uninitialized in this function
> /git/arm-soc/fs/splice.c: In function 'iter_file_splice_write':
> /git/arm-soc/fs/splice.c:716: warning: 'ret' may be used uninitialized
> in this function
> /git/arm-soc/net/core/dev.c: In function 'validate_xmit_skb_list':
> /git/arm-soc/net/core/dev.c:3003: warning: 'tail' may be used
> uninitialized in this function
> /git/arm-soc/kernel/printk/printk.c: In function 'devkmsg_sysctl_set_loglvl':
> /git/arm-soc/kernel/printk/printk.c:161: warning: 'old' may be used
> uninitialized in this function
> /git/arm-soc/kernel/time/ntp.c: In function 'ntp_validate_timex':
> /git/arm-soc/kernel/time/ntp.c:707: warning: comparison is always
> false due to limited range of data type
> /git/arm-soc/kernel/time/ntp.c:709: warning: comparison is always
> false due to limited range of data type
> /git/arm-soc/kernel/time/timekeeping.c: In function
> 'get_device_system_crosststamp':
> /git/arm-soc/kernel/time/timekeeping.c:1084: warning:
> 'cs_was_changed_seq' may be used uninitialized in this function
> /git/arm-soc/net/sunrpc/xdr.c: In function 'xdr_stream_decode_string_dup':
> /git/arm-soc/include/linux/sunrpc/xdr.h:409: warning: 'len' may be
> used uninitialized in this function
> /git/arm-soc/crypto/drbg.c: In function 'drbg_kcapi_random':
> /git/arm-soc/crypto/drbg.c:1865: internal compiler error: Segmentation fault
> Please submit a full bug report,
> with preprocessed source if appropriate.
> See <URL:http://gcc.gnu.org/bugs.html> for instructions.
> /git/arm-soc/scripts/Makefile.build:300: recipe for target
> 'crypto/drbg.o' failed
>
> So it still fails, but only because of one compiler error that I can avoid by
> disabling that driver, and you probably use a slightly patched compiler
> version that doesn't have this particular bug, or it was a regression between
> gcc-4.1.2 and 4.1.3.
Umm, I didn't build modules, sorry, because I don't usually use them with
those systems. However I have completed this step now and it also worked
just fine:
$ ls -la crypto/drbg.o
-rw-r--r-- 1 macro macro 14096 Apr 24 18:59 crypto/drbg.o
$ file crypto/drbg.o
crypto/drbg.o: ELF 32-bit LSB MIPS-I relocatable, MIPS, version 1 (SYSV), not stripped
$
so you are likely right that either I have a patch applied to my 4.1.2
build that has somehow fixed the ICE or it is a 4.1.3 regression (or a bad
patch in your 4.1.3 build).
BTW I do see these `may be used uninitialized' warnings just as Geert
does and even have a local patch, which I have neglected to submit, for a
64-bit configuration (`decstation_defconfig' is 32-bit) where in a single
place -Werror turns it into a build failure. I do not consider it a big
issue though, and might even wrap that patch up and submit sometime.
Maciej
next prev parent reply other threads:[~2017-04-24 18:30 UTC|newest]
Thread overview: 84+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-12-16 10:56 [RFC] minimum gcc version for kernel: raise to gcc-4.3 or 4.6? Arnd Bergmann
2016-12-16 10:56 ` Arnd Bergmann
2016-12-16 10:56 ` [PATCH 01/13] [HACK] gcc-4.5: avoid link errors for unused function pointers Arnd Bergmann
2016-12-16 10:56 ` Arnd Bergmann
2016-12-16 10:56 ` [PATCH 02/13] KVM: arm: fix gcc-4.5 build Arnd Bergmann
2016-12-16 10:56 ` Arnd Bergmann
2017-01-04 10:38 ` Christoffer Dall
2017-01-04 10:38 ` Christoffer Dall
2016-12-16 10:56 ` [PATCH 03/13] ARM: div64: fix building with gcc-4.5 and lower Arnd Bergmann
2016-12-16 10:56 ` Arnd Bergmann
2016-12-16 10:56 ` [PATCH 04/13] vfio-pci: use 32-bit comparisons for register address for gcc-4.5 Arnd Bergmann
2016-12-16 10:56 ` Arnd Bergmann
2016-12-16 15:30 ` Alex Williamson
2016-12-16 19:50 ` Arnd Bergmann
2016-12-16 10:56 ` [PATCH 05/13] clk: pxa: fix gcc-4.4 build Arnd Bergmann
2016-12-16 10:56 ` Arnd Bergmann
2016-12-16 10:56 ` [PATCH 06/13] ARM: atomic: " Arnd Bergmann
2016-12-16 10:56 ` Arnd Bergmann
2016-12-16 10:56 ` [PATCH 07/13] watchdog: kempld: fix gcc-4.3 build Arnd Bergmann
2016-12-16 10:56 ` Arnd Bergmann
2016-12-16 10:56 ` [PATCH 08/13] arm/arm64: xen: avoid gcc-4.4 warning Arnd Bergmann
2016-12-16 10:56 ` Arnd Bergmann
2016-12-16 10:56 ` [PATCH 09/13] ARM: mark cmpxchg and xchg __always_inline for gcc-4.3 Arnd Bergmann
2016-12-16 10:56 ` Arnd Bergmann
2016-12-16 10:56 ` [PATCH 10/13] asm-generic: mark cmpxchg as " Arnd Bergmann
2016-12-16 10:56 ` Arnd Bergmann
2016-12-16 10:56 ` [PATCH 11/13] fs: fix unsigned enum warning with gcc-4.2 Arnd Bergmann
2016-12-16 10:56 ` Arnd Bergmann
2017-01-03 22:47 ` Brendan Gregg
2017-02-28 21:53 ` Brendan Gregg
2016-12-16 10:56 ` [PATCH 12/13] KVM: arm: avoid binary number literals for gcc-4.2 Arnd Bergmann
2016-12-16 10:56 ` Arnd Bergmann
2017-01-04 10:39 ` Christoffer Dall
2017-01-04 10:39 ` Christoffer Dall
2016-12-16 10:56 ` [PATCH 13/13] ARM: avoid 'Q' asm constraint for gcc-4.1 and earlier Arnd Bergmann
2016-12-16 10:56 ` Arnd Bergmann
2016-12-16 11:14 ` [RFC] minimum gcc version for kernel: raise to gcc-4.3 or 4.6? Arnd Bergmann
2016-12-16 11:14 ` Arnd Bergmann
2017-04-16 19:52 ` Kees Cook
2017-04-20 10:15 ` Arnd Bergmann
2017-04-20 19:52 ` Kees Cook
2017-04-20 19:52 ` Kees Cook
2017-04-21 20:55 ` Arnd Bergmann
2017-04-21 20:55 ` Arnd Bergmann
2017-04-21 21:05 ` Kees Cook
2017-04-21 21:05 ` Kees Cook
2017-04-22 3:10 ` Maciej W. Rozycki
2017-04-22 3:10 ` Maciej W. Rozycki
2017-04-22 15:30 ` Arnd Bergmann
2017-04-22 15:30 ` Arnd Bergmann
2017-04-23 20:13 ` Geert Uytterhoeven
2017-04-23 20:13 ` Geert Uytterhoeven
2017-04-24 9:44 ` Arnd Bergmann
2017-04-24 9:44 ` Arnd Bergmann
2017-04-24 10:17 ` Geert Uytterhoeven
2017-04-24 10:17 ` Geert Uytterhoeven
2017-04-24 14:13 ` Arnd Bergmann
2017-04-24 16:53 ` Maciej W. Rozycki
2017-04-24 17:29 ` Arnd Bergmann
2017-04-24 18:16 ` Geert Uytterhoeven
2017-04-24 18:16 ` Geert Uytterhoeven
2017-04-24 18:30 ` Maciej W. Rozycki [this message]
2017-04-24 18:30 ` Maciej W. Rozycki
2017-04-24 20:30 ` Arnd Bergmann
2017-04-24 20:52 ` Kees Cook
2017-04-25 7:06 ` Geert Uytterhoeven
2017-04-25 7:06 ` Geert Uytterhoeven
2017-04-25 9:22 ` Suzuki K Poulose
2017-04-25 9:22 ` Suzuki K Poulose
2016-12-16 15:54 ` Geert Uytterhoeven
2016-12-16 15:54 ` Geert Uytterhoeven
2016-12-16 19:58 ` Arnd Bergmann
2016-12-16 19:58 ` Arnd Bergmann
2016-12-16 20:34 ` Geert Uytterhoeven
2016-12-16 20:34 ` Geert Uytterhoeven
2016-12-16 17:00 ` Sebastian Andrzej Siewior
2016-12-16 22:00 ` Arnd Bergmann
2016-12-16 22:00 ` Arnd Bergmann
2016-12-17 11:29 ` Sebastian Andrzej Siewior
2016-12-17 11:29 ` Sebastian Andrzej Siewior
2017-01-02 12:23 ` Russell King - ARM Linux
2017-01-02 12:23 ` Russell King - ARM Linux
2016-12-20 9:59 ` Heiko Carstens
2016-12-20 9:59 ` Heiko Carstens
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