* [tip:locking/core 6/10] arch/x86/include/asm/rmwcc.h:23:17: error: jump into statement expression
@ 2018-10-20 3:05 kbuild test robot
2018-10-22 10:08 ` Peter Zijlstra
0 siblings, 1 reply; 3+ messages in thread
From: kbuild test robot @ 2018-10-20 3:05 UTC (permalink / raw)
To: Peter Zijlstra
Cc: kbuild-all, linux-kernel, tipbuild, Ingo Molnar, Will Deacon
[-- Attachment #1: Type: text/plain, Size: 14636 bytes --]
tree: https://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git locking/core
head: 01a14bda11add9dcd4a59200f13834d634559935
commit: 7aa54be2976550f17c11a1c3e3630002dea39303 [6/10] locking/qspinlock, x86: Provide liveness guarantee
config: x86_64-randconfig-u0-10201040 (attached as .config)
compiler: gcc-5 (Debian 5.5.0-3) 5.4.1 20171010
reproduce:
git checkout 7aa54be2976550f17c11a1c3e3630002dea39303
# save the attached .config to linux build tree
make ARCH=x86_64
All errors (new ones prefixed by >>):
In file included from arch/x86/include/asm/atomic.h:5:0,
from include/linux/atomic.h:7,
from include/linux/crypto.h:20,
from arch/x86/kernel/asm-offsets.c:9:
arch/x86/include/asm/qspinlock.h: In function 'queued_fetch_set_pending_acquire':
>> arch/x86/include/asm/rmwcc.h:23:17: error: jump into statement expression
: clobbers : cc_label); \
^
include/linux/compiler.h:58:42: note: in definition of macro '__trace_if'
if (__builtin_constant_p(!!(cond)) ? !!(cond) : \
^
arch/x86/include/asm/qspinlock.h:18:2: note: in expansion of macro 'if'
if (GEN_BINARY_RMWcc(LOCK_PREFIX "btsl", lock->val.counter, c,
^
arch/x86/include/asm/rmwcc.h:21:2: note: in expansion of macro 'asm_volatile_goto'
asm_volatile_goto (fullop "; j" #cc " %l[cc_label]" \
^
arch/x86/include/asm/rmwcc.h:54:2: note: in expansion of macro '__GEN_RMWcc'
__GEN_RMWcc(op " %[val], " arg0, var, cc, \
^
arch/x86/include/asm/rmwcc.h:58:2: note: in expansion of macro 'GEN_BINARY_RMWcc_6'
GEN_BINARY_RMWcc_6(op, var, cc, vcon, val, "%[var]")
^
arch/x86/include/asm/rmwcc.h:9:30: note: in expansion of macro 'GEN_BINARY_RMWcc_5'
#define __RMWcc_CONCAT(a, b) a ## b
^
arch/x86/include/asm/rmwcc.h:10:28: note: in expansion of macro '__RMWcc_CONCAT'
#define RMWcc_CONCAT(a, b) __RMWcc_CONCAT(a, b)
^
arch/x86/include/asm/rmwcc.h:60:32: note: in expansion of macro 'RMWcc_CONCAT'
#define GEN_BINARY_RMWcc(X...) RMWcc_CONCAT(GEN_BINARY_RMWcc_, RMWcc_ARGS(X))(X)
^
arch/x86/include/asm/qspinlock.h:18:6: note: in expansion of macro 'GEN_BINARY_RMWcc'
if (GEN_BINARY_RMWcc(LOCK_PREFIX "btsl", lock->val.counter, c,
^
arch/x86/include/asm/rmwcc.h:25:1: note: label 'cc_label' defined here
cc_label: c = true; \
^
include/linux/compiler.h:58:30: note: in definition of macro '__trace_if'
if (__builtin_constant_p(!!(cond)) ? !!(cond) : \
^
arch/x86/include/asm/qspinlock.h:18:2: note: in expansion of macro 'if'
if (GEN_BINARY_RMWcc(LOCK_PREFIX "btsl", lock->val.counter, c,
^
arch/x86/include/asm/rmwcc.h:54:2: note: in expansion of macro '__GEN_RMWcc'
__GEN_RMWcc(op " %[val], " arg0, var, cc, \
^
arch/x86/include/asm/rmwcc.h:58:2: note: in expansion of macro 'GEN_BINARY_RMWcc_6'
GEN_BINARY_RMWcc_6(op, var, cc, vcon, val, "%[var]")
^
arch/x86/include/asm/rmwcc.h:9:30: note: in expansion of macro 'GEN_BINARY_RMWcc_5'
#define __RMWcc_CONCAT(a, b) a ## b
^
arch/x86/include/asm/rmwcc.h:10:28: note: in expansion of macro '__RMWcc_CONCAT'
#define RMWcc_CONCAT(a, b) __RMWcc_CONCAT(a, b)
^
arch/x86/include/asm/rmwcc.h:60:32: note: in expansion of macro 'RMWcc_CONCAT'
#define GEN_BINARY_RMWcc(X...) RMWcc_CONCAT(GEN_BINARY_RMWcc_, RMWcc_ARGS(X))(X)
^
arch/x86/include/asm/qspinlock.h:18:6: note: in expansion of macro 'GEN_BINARY_RMWcc'
if (GEN_BINARY_RMWcc(LOCK_PREFIX "btsl", lock->val.counter, c,
^
>> arch/x86/include/asm/rmwcc.h:25:1: error: duplicate label 'cc_label'
cc_label: c = true; \
^
include/linux/compiler.h:58:42: note: in definition of macro '__trace_if'
if (__builtin_constant_p(!!(cond)) ? !!(cond) : \
^
arch/x86/include/asm/qspinlock.h:18:2: note: in expansion of macro 'if'
if (GEN_BINARY_RMWcc(LOCK_PREFIX "btsl", lock->val.counter, c,
^
arch/x86/include/asm/rmwcc.h:54:2: note: in expansion of macro '__GEN_RMWcc'
__GEN_RMWcc(op " %[val], " arg0, var, cc, \
^
arch/x86/include/asm/rmwcc.h:58:2: note: in expansion of macro 'GEN_BINARY_RMWcc_6'
GEN_BINARY_RMWcc_6(op, var, cc, vcon, val, "%[var]")
^
arch/x86/include/asm/rmwcc.h:9:30: note: in expansion of macro 'GEN_BINARY_RMWcc_5'
#define __RMWcc_CONCAT(a, b) a ## b
^
arch/x86/include/asm/rmwcc.h:10:28: note: in expansion of macro '__RMWcc_CONCAT'
#define RMWcc_CONCAT(a, b) __RMWcc_CONCAT(a, b)
^
arch/x86/include/asm/rmwcc.h:60:32: note: in expansion of macro 'RMWcc_CONCAT'
#define GEN_BINARY_RMWcc(X...) RMWcc_CONCAT(GEN_BINARY_RMWcc_, RMWcc_ARGS(X))(X)
^
arch/x86/include/asm/qspinlock.h:18:6: note: in expansion of macro 'GEN_BINARY_RMWcc'
if (GEN_BINARY_RMWcc(LOCK_PREFIX "btsl", lock->val.counter, c,
^
arch/x86/include/asm/rmwcc.h:25:1: note: previous definition of 'cc_label' was here
cc_label: c = true; \
^
include/linux/compiler.h:58:30: note: in definition of macro '__trace_if'
if (__builtin_constant_p(!!(cond)) ? !!(cond) : \
^
arch/x86/include/asm/qspinlock.h:18:2: note: in expansion of macro 'if'
if (GEN_BINARY_RMWcc(LOCK_PREFIX "btsl", lock->val.counter, c,
^
arch/x86/include/asm/rmwcc.h:54:2: note: in expansion of macro '__GEN_RMWcc'
__GEN_RMWcc(op " %[val], " arg0, var, cc, \
^
arch/x86/include/asm/rmwcc.h:58:2: note: in expansion of macro 'GEN_BINARY_RMWcc_6'
GEN_BINARY_RMWcc_6(op, var, cc, vcon, val, "%[var]")
^
arch/x86/include/asm/rmwcc.h:9:30: note: in expansion of macro 'GEN_BINARY_RMWcc_5'
#define __RMWcc_CONCAT(a, b) a ## b
^
arch/x86/include/asm/rmwcc.h:10:28: note: in expansion of macro '__RMWcc_CONCAT'
#define RMWcc_CONCAT(a, b) __RMWcc_CONCAT(a, b)
^
arch/x86/include/asm/rmwcc.h:60:32: note: in expansion of macro 'RMWcc_CONCAT'
#define GEN_BINARY_RMWcc(X...) RMWcc_CONCAT(GEN_BINARY_RMWcc_, RMWcc_ARGS(X))(X)
^
arch/x86/include/asm/qspinlock.h:18:6: note: in expansion of macro 'GEN_BINARY_RMWcc'
if (GEN_BINARY_RMWcc(LOCK_PREFIX "btsl", lock->val.counter, c,
^
>> arch/x86/include/asm/rmwcc.h:23:17: error: jump into statement expression
: clobbers : cc_label); \
^
include/linux/compiler.h:69:16: note: in definition of macro '__trace_if'
______r = !!(cond); \
^
arch/x86/include/asm/qspinlock.h:18:2: note: in expansion of macro 'if'
if (GEN_BINARY_RMWcc(LOCK_PREFIX "btsl", lock->val.counter, c,
^
arch/x86/include/asm/rmwcc.h:21:2: note: in expansion of macro 'asm_volatile_goto'
asm_volatile_goto (fullop "; j" #cc " %l[cc_label]" \
^
arch/x86/include/asm/rmwcc.h:54:2: note: in expansion of macro '__GEN_RMWcc'
__GEN_RMWcc(op " %[val], " arg0, var, cc, \
^
arch/x86/include/asm/rmwcc.h:58:2: note: in expansion of macro 'GEN_BINARY_RMWcc_6'
GEN_BINARY_RMWcc_6(op, var, cc, vcon, val, "%[var]")
^
arch/x86/include/asm/rmwcc.h:9:30: note: in expansion of macro 'GEN_BINARY_RMWcc_5'
#define __RMWcc_CONCAT(a, b) a ## b
^
arch/x86/include/asm/rmwcc.h:10:28: note: in expansion of macro '__RMWcc_CONCAT'
#define RMWcc_CONCAT(a, b) __RMWcc_CONCAT(a, b)
^
arch/x86/include/asm/rmwcc.h:60:32: note: in expansion of macro 'RMWcc_CONCAT'
#define GEN_BINARY_RMWcc(X...) RMWcc_CONCAT(GEN_BINARY_RMWcc_, RMWcc_ARGS(X))(X)
^
arch/x86/include/asm/qspinlock.h:18:6: note: in expansion of macro 'GEN_BINARY_RMWcc'
if (GEN_BINARY_RMWcc(LOCK_PREFIX "btsl", lock->val.counter, c,
^
arch/x86/include/asm/rmwcc.h:25:1: note: label 'cc_label' defined here
cc_label: c = true; \
^
include/linux/compiler.h:58:30: note: in definition of macro '__trace_if'
if (__builtin_constant_p(!!(cond)) ? !!(cond) : \
^
arch/x86/include/asm/qspinlock.h:18:2: note: in expansion of macro 'if'
if (GEN_BINARY_RMWcc(LOCK_PREFIX "btsl", lock->val.counter, c,
^
arch/x86/include/asm/rmwcc.h:54:2: note: in expansion of macro '__GEN_RMWcc'
__GEN_RMWcc(op " %[val], " arg0, var, cc, \
^
arch/x86/include/asm/rmwcc.h:58:2: note: in expansion of macro 'GEN_BINARY_RMWcc_6'
GEN_BINARY_RMWcc_6(op, var, cc, vcon, val, "%[var]")
^
arch/x86/include/asm/rmwcc.h:9:30: note: in expansion of macro 'GEN_BINARY_RMWcc_5'
#define __RMWcc_CONCAT(a, b) a ## b
^
arch/x86/include/asm/rmwcc.h:10:28: note: in expansion of macro '__RMWcc_CONCAT'
#define RMWcc_CONCAT(a, b) __RMWcc_CONCAT(a, b)
^
arch/x86/include/asm/rmwcc.h:60:32: note: in expansion of macro 'RMWcc_CONCAT'
#define GEN_BINARY_RMWcc(X...) RMWcc_CONCAT(GEN_BINARY_RMWcc_, RMWcc_ARGS(X))(X)
^
arch/x86/include/asm/qspinlock.h:18:6: note: in expansion of macro 'GEN_BINARY_RMWcc'
if (GEN_BINARY_RMWcc(LOCK_PREFIX "btsl", lock->val.counter, c,
^
>> arch/x86/include/asm/rmwcc.h:25:1: error: duplicate label 'cc_label'
cc_label: c = true; \
^
include/linux/compiler.h:69:16: note: in definition of macro '__trace_if'
______r = !!(cond); \
^
arch/x86/include/asm/qspinlock.h:18:2: note: in expansion of macro 'if'
if (GEN_BINARY_RMWcc(LOCK_PREFIX "btsl", lock->val.counter, c,
^
arch/x86/include/asm/rmwcc.h:54:2: note: in expansion of macro '__GEN_RMWcc'
__GEN_RMWcc(op " %[val], " arg0, var, cc, \
^
arch/x86/include/asm/rmwcc.h:58:2: note: in expansion of macro 'GEN_BINARY_RMWcc_6'
GEN_BINARY_RMWcc_6(op, var, cc, vcon, val, "%[var]")
^
arch/x86/include/asm/rmwcc.h:9:30: note: in expansion of macro 'GEN_BINARY_RMWcc_5'
#define __RMWcc_CONCAT(a, b) a ## b
^
arch/x86/include/asm/rmwcc.h:10:28: note: in expansion of macro '__RMWcc_CONCAT'
#define RMWcc_CONCAT(a, b) __RMWcc_CONCAT(a, b)
^
arch/x86/include/asm/rmwcc.h:60:32: note: in expansion of macro 'RMWcc_CONCAT'
#define GEN_BINARY_RMWcc(X...) RMWcc_CONCAT(GEN_BINARY_RMWcc_, RMWcc_ARGS(X))(X)
^
arch/x86/include/asm/qspinlock.h:18:6: note: in expansion of macro 'GEN_BINARY_RMWcc'
if (GEN_BINARY_RMWcc(LOCK_PREFIX "btsl", lock->val.counter, c,
^
arch/x86/include/asm/rmwcc.h:25:1: note: previous definition of 'cc_label' was here
cc_label: c = true; \
^
include/linux/compiler.h:58:30: note: in definition of macro '__trace_if'
if (__builtin_constant_p(!!(cond)) ? !!(cond) : \
^
arch/x86/include/asm/qspinlock.h:18:2: note: in expansion of macro 'if'
if (GEN_BINARY_RMWcc(LOCK_PREFIX "btsl", lock->val.counter, c,
^
arch/x86/include/asm/rmwcc.h:54:2: note: in expansion of macro '__GEN_RMWcc'
__GEN_RMWcc(op " %[val], " arg0, var, cc, \
^
arch/x86/include/asm/rmwcc.h:58:2: note: in expansion of macro 'GEN_BINARY_RMWcc_6'
GEN_BINARY_RMWcc_6(op, var, cc, vcon, val, "%[var]")
^
arch/x86/include/asm/rmwcc.h:9:30: note: in expansion of macro 'GEN_BINARY_RMWcc_5'
#define __RMWcc_CONCAT(a, b) a ## b
^
arch/x86/include/asm/rmwcc.h:10:28: note: in expansion of macro '__RMWcc_CONCAT'
#define RMWcc_CONCAT(a, b) __RMWcc_CONCAT(a, b)
^
arch/x86/include/asm/rmwcc.h:60:32: note: in expansion of macro 'RMWcc_CONCAT'
#define GEN_BINARY_RMWcc(X...) RMWcc_CONCAT(GEN_BINARY_RMWcc_, RMWcc_ARGS(X))(X)
^
arch/x86/include/asm/qspinlock.h:18:6: note: in expansion of macro 'GEN_BINARY_RMWcc'
if (GEN_BINARY_RMWcc(LOCK_PREFIX "btsl", lock->val.counter, c,
^
make[2]: *** [arch/x86/kernel/asm-offsets.s] Error 1
make[2]: Target '__build' not remade because of errors.
make[1]: *** [prepare0] Error 2
make[1]: Target 'prepare' not remade because of errors.
make: *** [sub-make] Error 2
vim +23 arch/x86/include/asm/rmwcc.h
288e4521 Peter Zijlstra 2018-10-03 8
288e4521 Peter Zijlstra 2018-10-03 9 #define __RMWcc_CONCAT(a, b) a ## b
288e4521 Peter Zijlstra 2018-10-03 @10 #define RMWcc_CONCAT(a, b) __RMWcc_CONCAT(a, b)
288e4521 Peter Zijlstra 2018-10-03 11
700b7c54 Jan Beulich 2018-02-19 12 #define __CLOBBERS_MEM(clb...) "memory", ## clb
df340524 Kees Cook 2017-07-24 13
ba741e35 H. Peter Anvin 2016-06-08 14 #if !defined(__GCC_ASM_FLAG_OUTPUTS__) && defined(CC_HAVE_ASM_GOTO)
ba741e35 H. Peter Anvin 2016-06-08 15
ba741e35 H. Peter Anvin 2016-06-08 16 /* Use asm goto */
0c44c2d0 Peter Zijlstra 2013-09-11 17
288e4521 Peter Zijlstra 2018-10-03 18 #define __GEN_RMWcc(fullop, _var, cc, clobbers, ...) \
288e4521 Peter Zijlstra 2018-10-03 19 ({ \
288e4521 Peter Zijlstra 2018-10-03 20 bool c = false; \
18fe5822 H. Peter Anvin 2016-06-08 21 asm_volatile_goto (fullop "; j" #cc " %l[cc_label]" \
288e4521 Peter Zijlstra 2018-10-03 22 : : [var] "m" (_var), ## __VA_ARGS__ \
df340524 Kees Cook 2017-07-24 @23 : clobbers : cc_label); \
288e4521 Peter Zijlstra 2018-10-03 24 if (0) { \
288e4521 Peter Zijlstra 2018-10-03 @25 cc_label: c = true; \
288e4521 Peter Zijlstra 2018-10-03 26 } \
288e4521 Peter Zijlstra 2018-10-03 27 c; \
288e4521 Peter Zijlstra 2018-10-03 28 })
0c44c2d0 Peter Zijlstra 2013-09-11 29
:::::: The code at line 23 was first introduced by commit
:::::: df3405245a8535d2f20bcbdbb615385671cd0792 x86/asm: Add suffix macro for GEN_*_RMWcc()
:::::: TO: Kees Cook <keescook@chromium.org>
:::::: CC: Ingo Molnar <mingo@kernel.org>
---
0-DAY kernel test infrastructure Open Source Technology Center
https://lists.01.org/pipermail/kbuild-all Intel Corporation
[-- Attachment #2: .config.gz --]
[-- Type: application/gzip, Size: 24934 bytes --]
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [tip:locking/core 6/10] arch/x86/include/asm/rmwcc.h:23:17: error: jump into statement expression
2018-10-20 3:05 [tip:locking/core 6/10] arch/x86/include/asm/rmwcc.h:23:17: error: jump into statement expression kbuild test robot
@ 2018-10-22 10:08 ` Peter Zijlstra
2018-10-22 10:22 ` Will Deacon
0 siblings, 1 reply; 3+ messages in thread
From: Peter Zijlstra @ 2018-10-22 10:08 UTC (permalink / raw)
To: kbuild test robot
Cc: kbuild-all, linux-kernel, tipbuild, Ingo Molnar, Will Deacon,
Steven Rostedt
On Sat, Oct 20, 2018 at 11:05:11AM +0800, kbuild test robot wrote:
> tree: https://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git locking/core
> head: 01a14bda11add9dcd4a59200f13834d634559935
> commit: 7aa54be2976550f17c11a1c3e3630002dea39303 [6/10] locking/qspinlock, x86: Provide liveness guarantee
> config: x86_64-randconfig-u0-10201040 (attached as .config)
> compiler: gcc-5 (Debian 5.5.0-3) 5.4.1 20171010
> reproduce:
> git checkout 7aa54be2976550f17c11a1c3e3630002dea39303
> # save the attached .config to linux build tree
> make ARCH=x86_64
>
> All errors (new ones prefixed by >>):
>
> In file included from arch/x86/include/asm/atomic.h:5:0,
> from include/linux/atomic.h:7,
> from include/linux/crypto.h:20,
> from arch/x86/kernel/asm-offsets.c:9:
> arch/x86/include/asm/qspinlock.h: In function 'queued_fetch_set_pending_acquire':
> >> arch/x86/include/asm/rmwcc.h:23:17: error: jump into statement expression
> : clobbers : cc_label); \
> ^
> include/linux/compiler.h:58:42: note: in definition of macro '__trace_if'
> if (__builtin_constant_p(!!(cond)) ? !!(cond) : \
> ^
ARGH; so, this:
#define __GEN_RMWcc(fullop, _var, cc, clobbers, ...) \
({ \
bool c = false; \
asm_volatile_goto (fullop "; j" #cc " %l[cc_label]" \
: : [var] "m" (_var), ## __VA_ARGS__ \
: clobbers : cc_label); \
if (0) { \
cc_label: c = true; \
} \
c; \
})
static __always_inline u32 queued_fetch_set_pending_acquire(struct qspinlock *lock)
{
u32 val = 0;
if (GEN_BINARY_RMWcc(LOCK_PREFIX "btsl", lock->val.counter, c,
"I", _Q_PENDING_OFFSET))
val |= _Q_PENDING_VAL;
val |= atomic_read(&lock->val) & ~_Q_PENDING_MASK;
return val;
}
fails to compile when combined with this:
#define if(cond, ...) __trace_if( (cond , ## __VA_ARGS__) )
#define __trace_if(cond) \
if (__builtin_constant_p(!!(cond)) ? !!(cond) : \
({ \
int ______r; \
static struct ftrace_branch_data \
__attribute__((__aligned__(4))) \
__attribute__((section("_ftrace_branch"))) \
______f = { \
.func = __func__, \
.file = __FILE__, \
.line = __LINE__, \
}; \
______r = !!(cond); \
______f.miss_hit[______r]++; \
______r; \
}))
Because that moves the __GEN_RMWcc into a statement expression and GCC
apparently doesn't like labels inside statement expressions.
If we avoid if() and rewrite queued_fetch_set_pending_acquire() like so:
static __always_inline u32 queued_fetch_set_pending_acquire(struct qspinlock *lock)
{
bool pending;
u32 val;
pending = GEN_BINARY_RMWcc(LOCK_PREFIX "btsl", lock->val.counter, c,
"I", _Q_PENDING_OFFSET);
val = pending * _Q_PENDING_VAL;
val |= atomic_read(&lock->val) & ~_Q_PENDING_MASK;
return val;
}
then it compiles again; but urgh.
Anybody see a better solution?
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [tip:locking/core 6/10] arch/x86/include/asm/rmwcc.h:23:17: error: jump into statement expression
2018-10-22 10:08 ` Peter Zijlstra
@ 2018-10-22 10:22 ` Will Deacon
0 siblings, 0 replies; 3+ messages in thread
From: Will Deacon @ 2018-10-22 10:22 UTC (permalink / raw)
To: Peter Zijlstra
Cc: kbuild test robot, kbuild-all, linux-kernel, tipbuild,
Ingo Molnar, Steven Rostedt
On Mon, Oct 22, 2018 at 12:08:30PM +0200, Peter Zijlstra wrote:
> ARGH; so, this:
>
> #define __GEN_RMWcc(fullop, _var, cc, clobbers, ...) \
> ({ \
> bool c = false; \
> asm_volatile_goto (fullop "; j" #cc " %l[cc_label]" \
> : : [var] "m" (_var), ## __VA_ARGS__ \
> : clobbers : cc_label); \
> if (0) { \
> cc_label: c = true; \
> } \
> c; \
> })
>
> static __always_inline u32 queued_fetch_set_pending_acquire(struct qspinlock *lock)
> {
> u32 val = 0;
>
> if (GEN_BINARY_RMWcc(LOCK_PREFIX "btsl", lock->val.counter, c,
> "I", _Q_PENDING_OFFSET))
> val |= _Q_PENDING_VAL;
>
> val |= atomic_read(&lock->val) & ~_Q_PENDING_MASK;
>
> return val;
> }
>
> fails to compile when combined with this:
>
> #define if(cond, ...) __trace_if( (cond , ## __VA_ARGS__) )
Rosteeeedt!
> #define __trace_if(cond) \
> if (__builtin_constant_p(!!(cond)) ? !!(cond) : \
> ({ \
> int ______r; \
> static struct ftrace_branch_data \
> __attribute__((__aligned__(4))) \
> __attribute__((section("_ftrace_branch"))) \
> ______f = { \
> .func = __func__, \
> .file = __FILE__, \
> .line = __LINE__, \
> }; \
> ______r = !!(cond); \
> ______f.miss_hit[______r]++; \
> ______r; \
> }))
>
> Because that moves the __GEN_RMWcc into a statement expression and GCC
> apparently doesn't like labels inside statement expressions.
>
> If we avoid if() and rewrite queued_fetch_set_pending_acquire() like so:
>
> static __always_inline u32 queued_fetch_set_pending_acquire(struct qspinlock *lock)
> {
> bool pending;
> u32 val;
>
> pending = GEN_BINARY_RMWcc(LOCK_PREFIX "btsl", lock->val.counter, c,
> "I", _Q_PENDING_OFFSET);
>
> val = pending * _Q_PENDING_VAL;
> val |= atomic_read(&lock->val) & ~_Q_PENDING_MASK;
>
> return val;
> }
>
> then it compiles again; but urgh.
>
> Anybody see a better solution?
No, that looks about right to me, but please throw in a comment so that we
don't "fix" this in the future.
Will
^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2018-10-22 10:23 UTC | newest]
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2018-10-20 3:05 [tip:locking/core 6/10] arch/x86/include/asm/rmwcc.h:23:17: error: jump into statement expression kbuild test robot
2018-10-22 10:08 ` Peter Zijlstra
2018-10-22 10:22 ` Will Deacon
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