Buildresult: linus/parisc-defconfig/parisc-gcc8 built on Jun 4 2019, 21:01

kisskb

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Status:	OK
Date/Time:	Jun 4 2019, 21:01
Duration:	0:01:16.410007
Builder:	blade4b
Revision:	rcu: locking and unlocking need to always be at least barriers (`66be4e66a7f422128748e3c3ef6ee72b20a6197b)`
Target:	linus/parisc-defconfig/parisc-gcc8
Branch:	linus
Compiler:	parisc-gcc8 (hppa-linux-gcc (GCC) 8.1.0 / GNU ld (GNU Binutils) 2.30)
Config:	defconfig (download)
Log:	Download original Possible warnings (4) arch/parisc/math-emu/cnv_float.h:50:52: warning: '<<' in boolean context, did you mean '<' ? [-Wint-in-bool-context] arch/parisc/math-emu/cnv_float.h:54:21: warning: '<<' in boolean context, did you mean '<' ? [-Wint-in-bool-context] arch/parisc/math-emu/cnv_float.h:58:27: warning: '<<' in boolean context, did you mean '<' ? [-Wint-in-bool-context] arch/parisc/math-emu/cnv_float.h:62:31: warning: '<<' in boolean context, did you mean '<' ? [-Wint-in-bool-context] Full Log # git rev-parse -q --verify 66be4e66a7f422128748e3c3ef6ee72b20a6197b^{commit} 66be4e66a7f422128748e3c3ef6ee72b20a6197b already have revision, skipping fetch # git checkout -q -f -B kisskb 66be4e66a7f422128748e3c3ef6ee72b20a6197b # git clean -qxdf # < git log -1 # commit 66be4e66a7f422128748e3c3ef6ee72b20a6197b # Author: Linus Torvalds <torvalds@linux-foundation.org> # Date: Mon Jun 3 13:26:20 2019 -0700 # # rcu: locking and unlocking need to always be at least barriers # # Herbert Xu pointed out that commit bb73c52bad36 ("rcu: Don't disable # preemption for Tiny and Tree RCU readers") was incorrect in making the # preempt_disable/enable() be conditional on CONFIG_PREEMPT_COUNT. # # If CONFIG_PREEMPT_COUNT isn't enabled, the preemption enable/disable is # a no-op, but still is a compiler barrier. # # And RCU locking still _needs_ that compiler barrier. # # It is simply fundamentally not true that RCU locking would be a complete # no-op: we still need to guarantee (for example) that things that can # trap and cause preemption cannot migrate into the RCU locked region. # # The way we do that is by making it a barrier. # # See for example commit 386afc91144b ("spinlocks and preemption points # need to be at least compiler barriers") from back in 2013 that had # similar issues with spinlocks that become no-ops on UP: they must still # constrain the compiler from moving other operations into the critical # region. # # Now, it is true that a lot of RCU operations already use READ_ONCE() and # WRITE_ONCE() (which in practice likely would never be re-ordered wrt # anything remotely interesting), but it is also true that that is not # globally the case, and that it's not even necessarily always possible # (ie bitfields etc). # # Reported-by: Herbert Xu <herbert@gondor.apana.org.au> # Fixes: bb73c52bad36 ("rcu: Don't disable preemption for Tiny and Tree RCU readers") # Cc: stable@kernel.org # Cc: Boqun Feng <boqun.feng@gmail.com> # Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> # Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> # < /opt/cross/kisskb/korg/gcc-8.1.0-nolibc/hppa-linux/bin/hppa-linux-gcc --version # < /opt/cross/kisskb/korg/gcc-8.1.0-nolibc/hppa-linux/bin/hppa-linux-ld --version # < git log --format=%s --max-count=1 66be4e66a7f422128748e3c3ef6ee72b20a6197b # < make -s -j 24 ARCH=parisc O=/kisskb/build/linus_parisc-defconfig_parisc CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-8.1.0-nolibc/hppa-linux/bin/hppa-linux- defconfig # make -s -j 24 ARCH=parisc O=/kisskb/build/linus_parisc-defconfig_parisc CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-8.1.0-nolibc/hppa-linux/bin/hppa-linux- In file included from /kisskb/src/arch/parisc/math-emu/fcnvxf.c:38: /kisskb/src/arch/parisc/math-emu/fcnvxf.c: In function 'sgl_to_sgl_fcnvxf': /kisskb/src/arch/parisc/math-emu/cnv_float.h:50:52: warning: '<<' in boolean context, did you mean '<' ? [-Wint-in-bool-context] #define Int_isinexact_to_sgl(int_value) (int_value << 33 - SGL_EXP_LENGTH) ~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~ /kisskb/src/arch/parisc/math-emu/fcnvxf.c:88:6: note: in expansion of macro 'Int_isinexact_to_sgl' if (Int_isinexact_to_sgl(src)) { ^~~~~~~~~~~~~~~~~~~~ /kisskb/src/arch/parisc/math-emu/cnv_float.h:54:21: warning: '<<' in boolean context, did you mean '<' ? [-Wint-in-bool-context] if ((int_value << 34 - SGL_EXP_LENGTH) \|\| Slow(sgl_value)) \ ~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~ /kisskb/src/arch/parisc/math-emu/fcnvxf.c:99:5: note: in expansion of macro 'Sgl_roundnearest_from_int' Sgl_roundnearest_from_int(src,result); ^~~~~~~~~~~~~~~~~~~~~~~~~ /kisskb/src/arch/parisc/math-emu/fcnvxf.c: In function 'dbl_to_sgl_fcnvxf': /kisskb/src/arch/parisc/math-emu/cnv_float.h:58:27: warning: '<<' in boolean context, did you mean '<' ? [-Wint-in-bool-context] ((Dintp1(dint_valueA) << 33 - SGL_EXP_LENGTH) \|\| Dintp2(dint_valueB)) ~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~ /kisskb/src/arch/parisc/math-emu/fcnvxf.c:244:6: note: in expansion of macro 'Dint_isinexact_to_sgl' if (Dint_isinexact_to_sgl(srcp1,srcp2)) { ^~~~~~~~~~~~~~~~~~~~~ /kisskb/src/arch/parisc/math-emu/cnv_float.h:62:31: warning: '<<' in boolean context, did you mean '<' ? [-Wint-in-bool-context] if ((Dintp1(dint_valueA) << 34 - SGL_EXP_LENGTH) \|\| \ ~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~ /kisskb/src/arch/parisc/math-emu/fcnvxf.c:255:5: note: in expansion of macro 'Sgl_roundnearest_from_dint' Sgl_roundnearest_from_dint(srcp1,srcp2,result); ^~~~~~~~~~~~~~~~~~~~~~~~~~ Completed OK # rm -rf /kisskb/build/linus_parisc-defconfig_parisc # Build took: 0:01:16.410007

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