From: "Martin Liška" <mliska@suse.cz>
To: Michal Hocko <mhocko@suse.cz>,
kbuild test robot <fengguang.wu@intel.com>
Cc: kbuild-all@01.org, linux-mm@kvack.org,
Jason Baron <jbaron@akamai.com>,
Andrew Morton <akpm@linux-foundation.org>
Subject: Re: [memcg:auto-latest 238/243] include/linux/compiler-gcc.h:243:38: error: impossible constraint in 'asm'
Date: Mon, 1 Aug 2016 13:27:59 +0200 [thread overview]
Message-ID: <35a0878d-84bd-ad93-8810-23c861ed464e@suse.cz> (raw)
In-Reply-To: <20160801110859.GC13544@dhcp22.suse.cz>
On 08/01/2016 01:09 PM, Michal Hocko wrote:
> [CC our gcc guy - I guess he has some theory for this]
>
> On Sun 31-07-16 14:11:25, Michal Hocko wrote:
>> It seems that this has been already reported and Jason has noticed [1] that
>> the problem is in the disabled optimizations:
>>
>> $ grep CRYPTO_DEV_UX500_DEBUG .config
>> CONFIG_CRYPTO_DEV_UX500_DEBUG=y
>>
>> if I disable this particular option the code compiles just fine. I have
>> no idea what is wrong about the code but it seems to depend on
>> optimizations enabled which sounds a bit scrary...
>>
>> [1] http://www.spinics.net/lists/linux-mm/msg109590.html
Hi.
The difference is that w/o any optimization level, GCC doesn't make %c0 an
intermediate integer operand [1] (see description of "i" constraint).
If I change "i" to "X" (Any operand whatsoever is allowed.) and "%c0" to "%k0" I get following assembly:
cryp_enable_irq_src:
@ args = 0, pretend = 0, frame = 48
@ frame_needed = 1, uses_anonymous_args = 0
push {fp, lr}
add fp, sp, #4
sub sp, sp, #48
str r0, [fp, #-48]
str r1, [fp, #-52]
ldr r3, .L6
str r3, [fp, #-20]
mov r3, #1
strb r3, [fp, #-21]
ldrb r3, [fp, #-21] @ zero_extendqisi2
ldr r2, [fp, #-20]
add r3, r2, r3
.syntax divided
@ 1607 "/home/marxin/Programming/testcases/asm.i" 1
1:
nop
.pushsection __jump_table, "aw"
.word 1b, .L2, r3 # The operand is the register r3
.popsection
.arm
.syntax unified
mov r3, #0
b .L3
.L2:
While using -O2 really make %c0 an intermediate operand:
cryp_enable_irq_src:
@ args = 0, pretend = 0, frame = 0
@ frame_needed = 0, uses_anonymous_args = 0
push {r4, r5, r6, lr}
mov r5, r0
mov r4, r1
.syntax divided
@ 1607 "/home/marxin/Programming/testcases/asm.i" 1
1:
nop
.pushsection __jump_table, "aw"
.word 1b, .L2, #.LANCHOR0+21 # The operand is the intermediate operand #.LANCHOR0+21
.popsection
Martin
[1] https://gcc.gnu.org/onlinedocs/gcc/Simple-Constraints.html#Simple-Constraints
>>
>> On Sat 30-07-16 05:04:07, Wu Fengguang wrote:
>>> tree: https://git.kernel.org/pub/scm/linux/kernel/git/mhocko/mm.git auto-latest
>>> head: a7bf930624bb1d3368b71b79c5e3351b5d03aa9f
>>> commit: 966a2c66863bb2d984b9b49aee271de502cf8747 [238/243] dynamic_debug: add jump label support
>>> config: arm-allmodconfig (attached as .config)
>>> compiler: arm-linux-gnueabi-gcc (Debian 5.4.0-6) 5.4.0 20160609
>>> reproduce:
>>> wget https://git.kernel.org/cgit/linux/kernel/git/wfg/lkp-tests.git/plain/sbin/make.cross -O ~/bin/make.cross
>>> chmod +x ~/bin/make.cross
>>> git checkout 966a2c66863bb2d984b9b49aee271de502cf8747
>>> # save the attached .config to linux build tree
>>> make.cross ARCH=arm
>>>
>>> All errors (new ones prefixed by >>):
>>>
>>> In file included from include/linux/compiler.h:58:0,
>>> from include/linux/linkage.h:4,
>>> from include/linux/kernel.h:6,
>>> from drivers/crypto/ux500/cryp/cryp_irq.c:11:
>>> arch/arm/include/asm/jump_label.h: In function 'cryp_enable_irq_src':
>>> include/linux/compiler-gcc.h:243:38: warning: asm operand 0 probably doesn't match constraints
>>> #define asm_volatile_goto(x...) do { asm goto(x); asm (""); } while (0)
>>> ^
>>> arch/arm/include/asm/jump_label.h:13:2: note: in expansion of macro 'asm_volatile_goto'
>>> asm_volatile_goto("1:\n\t"
>>> ^
>>>>> include/linux/compiler-gcc.h:243:38: error: impossible constraint in 'asm'
>>> #define asm_volatile_goto(x...) do { asm goto(x); asm (""); } while (0)
>>> ^
>>> arch/arm/include/asm/jump_label.h:13:2: note: in expansion of macro 'asm_volatile_goto'
>>> asm_volatile_goto("1:\n\t"
>>> ^
>>> arch/arm/include/asm/jump_label.h: In function 'cryp_disable_irq_src':
>>> include/linux/compiler-gcc.h:243:38: warning: asm operand 0 probably doesn't match constraints
>>> #define asm_volatile_goto(x...) do { asm goto(x); asm (""); } while (0)
>>> ^
>>> arch/arm/include/asm/jump_label.h:13:2: note: in expansion of macro 'asm_volatile_goto'
>>> asm_volatile_goto("1:\n\t"
>>> ^
>>> --
>>> In file included from include/linux/compiler.h:58:0,
>>> from include/linux/err.h:4,
>>> from include/linux/clk.h:15,
>>> from drivers/crypto/ux500/cryp/cryp_core.c:12:
>>> arch/arm/include/asm/jump_label.h: In function 'cryp_interrupt_handler':
>>> include/linux/compiler-gcc.h:243:38: warning: asm operand 0 probably doesn't match constraints
>>> #define asm_volatile_goto(x...) do { asm goto(x); asm (""); } while (0)
>>> ^
>>> arch/arm/include/asm/jump_label.h:13:2: note: in expansion of macro 'asm_volatile_goto'
>>> asm_volatile_goto("1:\n\t"
>>> ^
>>>>> include/linux/compiler-gcc.h:243:38: error: impossible constraint in 'asm'
>>> #define asm_volatile_goto(x...) do { asm goto(x); asm (""); } while (0)
>>> ^
>>> arch/arm/include/asm/jump_label.h:13:2: note: in expansion of macro 'asm_volatile_goto'
>>> asm_volatile_goto("1:\n\t"
>>> ^
>>> arch/arm/include/asm/jump_label.h: In function 'cfg_iv':
>>> include/linux/compiler-gcc.h:243:38: warning: asm operand 0 probably doesn't match constraints
>>> #define asm_volatile_goto(x...) do { asm goto(x); asm (""); } while (0)
>>> ^
>>> arch/arm/include/asm/jump_label.h:13:2: note: in expansion of macro 'asm_volatile_goto'
>>> asm_volatile_goto("1:\n\t"
>>> ^
>>> arch/arm/include/asm/jump_label.h: In function 'cfg_ivs':
>>> include/linux/compiler-gcc.h:243:38: warning: asm operand 0 probably doesn't match constraints
>>> #define asm_volatile_goto(x...) do { asm goto(x); asm (""); } while (0)
>>> ^
>>> arch/arm/include/asm/jump_label.h:13:2: note: in expansion of macro 'asm_volatile_goto'
>>> asm_volatile_goto("1:\n\t"
>>> ^
>>> arch/arm/include/asm/jump_label.h: In function 'set_key':
>>> include/linux/compiler-gcc.h:243:38: warning: asm operand 0 probably doesn't match constraints
>>> #define asm_volatile_goto(x...) do { asm goto(x); asm (""); } while (0)
>>> ^
>>> arch/arm/include/asm/jump_label.h:13:2: note: in expansion of macro 'asm_volatile_goto'
>>> asm_volatile_goto("1:\n\t"
>>> ^
>>> arch/arm/include/asm/jump_label.h: In function 'cfg_keys':
>>> include/linux/compiler-gcc.h:243:38: warning: asm operand 0 probably doesn't match constraints
>>> #define asm_volatile_goto(x...) do { asm goto(x); asm (""); } while (0)
>>> ^
>>> arch/arm/include/asm/jump_label.h:13:2: note: in expansion of macro 'asm_volatile_goto'
>>> asm_volatile_goto("1:\n\t"
>>> ^
>>> arch/arm/include/asm/jump_label.h: In function 'cryp_get_device_data':
>>> include/linux/compiler-gcc.h:243:38: warning: asm operand 0 probably doesn't match constraints
>>> #define asm_volatile_goto(x...) do { asm goto(x); asm (""); } while (0)
>>> ^
>>> arch/arm/include/asm/jump_label.h:13:2: note: in expansion of macro 'asm_volatile_goto'
>>> asm_volatile_goto("1:\n\t"
>>> ^
>>> arch/arm/include/asm/jump_label.h: In function 'cryp_dma_out_callback':
>>> include/linux/compiler-gcc.h:243:38: warning: asm operand 0 probably doesn't match constraints
>>> #define asm_volatile_goto(x...) do { asm goto(x); asm (""); } while (0)
>>> ^
>>> arch/arm/include/asm/jump_label.h:13:2: note: in expansion of macro 'asm_volatile_goto'
>>> asm_volatile_goto("1:\n\t"
>>> ^
>>> arch/arm/include/asm/jump_label.h: In function 'cryp_set_dma_transfer':
>>> include/linux/compiler-gcc.h:243:38: warning: asm operand 0 probably doesn't match constraints
>>> #define asm_volatile_goto(x...) do { asm goto(x); asm (""); } while (0)
>>> ^
>>> arch/arm/include/asm/jump_label.h:13:2: note: in expansion of macro 'asm_volatile_goto'
>>> asm_volatile_goto("1:\n\t"
>>> ^
>>> include/linux/compiler-gcc.h:243:38: warning: asm operand 0 probably doesn't match constraints
>>> #define asm_volatile_goto(x...) do { asm goto(x); asm (""); } while (0)
>>> ^
>>> arch/arm/include/asm/jump_label.h:13:2: note: in expansion of macro 'asm_volatile_goto'
>>> asm_volatile_goto("1:\n\t"
>>> ^
>>> include/linux/compiler-gcc.h:243:38: warning: asm operand 0 probably doesn't match constraints
>>> #define asm_volatile_goto(x...) do { asm goto(x); asm (""); } while (0)
>>> ^
>>> arch/arm/include/asm/jump_label.h:13:2: note: in expansion of macro 'asm_volatile_goto'
>>> asm_volatile_goto("1:\n\t"
>>> ^
>>> include/linux/compiler-gcc.h:243:38: warning: asm operand 0 probably doesn't match constraints
>>> #define asm_volatile_goto(x...) do { asm goto(x); asm (""); } while (0)
>>> ^
>>> arch/arm/include/asm/jump_label.h:13:2: note: in expansion of macro 'asm_volatile_goto'
>>> asm_volatile_goto("1:\n\t"
>>> ^
>>> include/linux/compiler-gcc.h:243:38: warning: asm operand 0 probably doesn't match constraints
>>> #define asm_volatile_goto(x...) do { asm goto(x); asm (""); } while (0)
>>> ^
>>> arch/arm/include/asm/jump_label.h:13:2: note: in expansion of macro 'asm_volatile_goto'
>>> asm_volatile_goto("1:\n\t"
>>> ^
>>> include/linux/compiler-gcc.h:243:38: warning: asm operand 0 probably doesn't match constraints
>>> #define asm_volatile_goto(x...) do { asm goto(x); asm (""); } while (0)
>>> ^
>>> arch/arm/include/asm/jump_label.h:13:2: note: in expansion of macro 'asm_volatile_goto'
>>> asm_volatile_goto("1:\n\t"
>>> ^
>>> arch/arm/include/asm/jump_label.h: In function 'cryp_dma_done':
>>> include/linux/compiler-gcc.h:243:38: warning: asm operand 0 probably doesn't match constraints
>>> #define asm_volatile_goto(x...) do { asm goto(x); asm (""); } while (0)
>>> ^
>>> arch/arm/include/asm/jump_label.h:13:2: note: in expansion of macro 'asm_volatile_goto'
>>> asm_volatile_goto("1:\n\t"
>>> ^
>>> arch/arm/include/asm/jump_label.h: In function 'cryp_dma_write':
>>> include/linux/compiler-gcc.h:243:38: warning: asm operand 0 probably doesn't match constraints
>>> #define asm_volatile_goto(x...) do { asm goto(x); asm (""); } while (0)
>>> ^
>>> arch/arm/include/asm/jump_label.h:13:2: note: in expansion of macro 'asm_volatile_goto'
>>> asm_volatile_goto("1:\n\t"
>>> ^
>>> include/linux/compiler-gcc.h:243:38: warning: asm operand 0 probably doesn't match constraints
>>> #define asm_volatile_goto(x...) do { asm goto(x); asm (""); } while (0)
>>>
>>> vim +/asm +243 include/linux/compiler-gcc.h
>>>
>>> a744fd17 Rasmus Villemoes 2015-11-05 227 * returning extra information in the low bits (but in that case the
>>> a744fd17 Rasmus Villemoes 2015-11-05 228 * compiler should see some alignment anyway, when the return value is
>>> a744fd17 Rasmus Villemoes 2015-11-05 229 * massaged by 'flags = ptr & 3; ptr &= ~3;').
>>> a744fd17 Rasmus Villemoes 2015-11-05 230 */
>>> a744fd17 Rasmus Villemoes 2015-11-05 231 #define __assume_aligned(a, ...) __attribute__((__assume_aligned__(a, ## __VA_ARGS__)))
>>> a744fd17 Rasmus Villemoes 2015-11-05 232 #endif
>>> a744fd17 Rasmus Villemoes 2015-11-05 233
>>> cb984d10 Joe Perches 2015-06-25 234 /*
>>> cb984d10 Joe Perches 2015-06-25 235 * GCC 'asm goto' miscompiles certain code sequences:
>>> cb984d10 Joe Perches 2015-06-25 236 *
>>> cb984d10 Joe Perches 2015-06-25 237 * http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58670
>>> cb984d10 Joe Perches 2015-06-25 238 *
>>> cb984d10 Joe Perches 2015-06-25 239 * Work it around via a compiler barrier quirk suggested by Jakub Jelinek.
>>> cb984d10 Joe Perches 2015-06-25 240 *
>>> cb984d10 Joe Perches 2015-06-25 241 * (asm goto is automatically volatile - the naming reflects this.)
>>> cb984d10 Joe Perches 2015-06-25 242 */
>>> cb984d10 Joe Perches 2015-06-25 @243 #define asm_volatile_goto(x...) do { asm goto(x); asm (""); } while (0)
>>> cb984d10 Joe Perches 2015-06-25 244
>>> cb984d10 Joe Perches 2015-06-25 245 #ifdef CONFIG_ARCH_USE_BUILTIN_BSWAP
>>> cb984d10 Joe Perches 2015-06-25 246 #if GCC_VERSION >= 40400
>>> cb984d10 Joe Perches 2015-06-25 247 #define __HAVE_BUILTIN_BSWAP32__
>>> cb984d10 Joe Perches 2015-06-25 248 #define __HAVE_BUILTIN_BSWAP64__
>>> cb984d10 Joe Perches 2015-06-25 249 #endif
>>> 8634de6d Josh Poimboeuf 2016-05-06 250 #if GCC_VERSION >= 40800
>>> cb984d10 Joe Perches 2015-06-25 251 #define __HAVE_BUILTIN_BSWAP16__
>>>
>>> :::::: The code at line 243 was first introduced by commit
>>> :::::: cb984d101b30eb7478d32df56a0023e4603cba7f compiler-gcc: integrate the various compiler-gcc[345].h files
>>>
>>> :::::: TO: Joe Perches <joe@perches.com>
>>> :::::: CC: Linus Torvalds <torvalds@linux-foundation.org>
>>>
>>> ---
>>> 0-DAY kernel test infrastructure Open Source Technology Center
>>> https://lists.01.org/pipermail/kbuild-all Intel Corporation
>>
>>
>>
>> --
>> Michal Hocko
>> SUSE Labs
>
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org. For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>
next prev parent reply other threads:[~2016-08-01 11:28 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-07-29 21:04 kbuild test robot
2016-07-31 12:11 ` Michal Hocko
2016-08-01 11:09 ` Michal Hocko
2016-08-01 11:27 ` Martin Liška [this message]
2016-08-01 12:41 ` oliver
2016-08-03 5:17 ` Balbir Singh
2016-08-02 15:18 ` Jason Baron
2016-08-01 15:00 ` Jason Baron
2016-08-01 15:29 ` Michal Hocko
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=35a0878d-84bd-ad93-8810-23c861ed464e@suse.cz \
--to=mliska@suse.cz \
--cc=akpm@linux-foundation.org \
--cc=fengguang.wu@intel.com \
--cc=jbaron@akamai.com \
--cc=kbuild-all@01.org \
--cc=linux-mm@kvack.org \
--cc=mhocko@suse.cz \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox