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From: Konstantin S. <kon...@gm...> - 2009-10-22 07:36:52
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-valgrind-users+valgrind-developers I observe a situation where the number of invocations of PRE(sys_epoll_wait) is greater than the number of invocations of POST(sys_epoll_wait). Is that expected? This is causing memcheck to think that memory passed to epoll_wait() as a second parameter is left uninitialized... Thanks, --kcc On Tue, Oct 20, 2009 at 3:30 PM, Konstantin Serebryany < kon...@gm...> wrote: > Hi, > I am investigating a memcheck's report near a call to epoll_wait(). > I am running my program (sorry, not small test case) with > --trace-syscalls=yes. > > Usually I get this: > SYSCALL[29628,125](232) sys_epoll_wait ( 62, 0x1540ca30, 1024, 1000 ) --> > [async] ... > SYSCALL[29628,125](232) ... [async] --> Success(0x0:0x0) > I assume these two lines come from PRE(sys_epoll_wait) and > POST(sys_epoll_wait). > > But sometimes I get this: > SYSCALL[29628,156](232) sys_epoll_wait ( 96, 0x15948a30, 1024, 417 ) --> > [async] ... > SYSCALL[29628,156]( 15) sys_rt_sigreturn ( ) --> [pre-success] > NoWriteResult > > So, POST(sys_epoll_wait) does not get called and memcheck thinks that the > second parameter of epoll_wait is uninitialized. > > What does this sys_rt_sigreturn mean? Why POST(sys_epoll_wait) is not > called? > Any idea? > > Thanks, > > --kcc > > > > > |
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From: Konstantin S. <kon...@gm...> - 2009-10-28 04:54:54
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Any suggestion? On Thu, Oct 22, 2009 at 10:36 AM, Konstantin Serebryany < kon...@gm...> wrote: > -valgrind-users > +valgrind-developers > > I observe a situation where the number of invocations > of PRE(sys_epoll_wait) is greater than the number of invocations > of POST(sys_epoll_wait). > Is that expected? > > This is causing memcheck to think that memory passed to epoll_wait() as a > second parameter is left uninitialized... > > Thanks, > > --kcc > > > > > > On Tue, Oct 20, 2009 at 3:30 PM, Konstantin Serebryany < > kon...@gm...> wrote: > >> Hi, >> >> I am investigating a memcheck's report near a call to epoll_wait(). >> I am running my program (sorry, not small test case) with >> --trace-syscalls=yes. >> >> Usually I get this: >> SYSCALL[29628,125](232) sys_epoll_wait ( 62, 0x1540ca30, 1024, 1000 ) --> >> [async] ... >> SYSCALL[29628,125](232) ... [async] --> Success(0x0:0x0) >> I assume these two lines come from PRE(sys_epoll_wait) and >> POST(sys_epoll_wait). >> >> But sometimes I get this: >> SYSCALL[29628,156](232) sys_epoll_wait ( 96, 0x15948a30, 1024, 417 ) --> >> [async] ... >> SYSCALL[29628,156]( 15) sys_rt_sigreturn ( ) --> [pre-success] >> NoWriteResult >> >> So, POST(sys_epoll_wait) does not get called and memcheck thinks that the >> second parameter of epoll_wait is uninitialized. >> >> What does this sys_rt_sigreturn mean? Why POST(sys_epoll_wait) is not >> called? >> Any idea? >> >> Thanks, >> >> --kcc >> >> >> >> >> > |
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From: Konstantin S. <kon...@gm...> - 2009-10-29 09:19:33
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This affects other systems calls, not just epoll_wait. I submitted https://bugs.kde.org/show_bug.cgi?id=212267 with an example for read() system call. I'd appreciate a comment. Thanks, --kcc On Wed, Oct 28, 2009 at 7:54 AM, Konstantin Serebryany < kon...@gm...> wrote: > Any suggestion? > > > On Thu, Oct 22, 2009 at 10:36 AM, Konstantin Serebryany < > kon...@gm...> wrote: > >> -valgrind-users >> +valgrind-developers >> >> I observe a situation where the number of invocations >> of PRE(sys_epoll_wait) is greater than the number of invocations >> of POST(sys_epoll_wait). >> Is that expected? >> >> This is causing memcheck to think that memory passed to epoll_wait() as a >> second parameter is left uninitialized... >> >> Thanks, >> >> --kcc >> >> >> >> >> >> On Tue, Oct 20, 2009 at 3:30 PM, Konstantin Serebryany < >> kon...@gm...> wrote: >> >>> Hi, >>> >>> I am investigating a memcheck's report near a call to epoll_wait(). >>> I am running my program (sorry, not small test case) with >>> --trace-syscalls=yes. >>> >>> Usually I get this: >>> SYSCALL[29628,125](232) sys_epoll_wait ( 62, 0x1540ca30, 1024, 1000 ) --> >>> [async] ... >>> SYSCALL[29628,125](232) ... [async] --> Success(0x0:0x0) >>> I assume these two lines come from PRE(sys_epoll_wait) and >>> POST(sys_epoll_wait). >>> >>> But sometimes I get this: >>> SYSCALL[29628,156](232) sys_epoll_wait ( 96, 0x15948a30, 1024, 417 ) --> >>> [async] ... >>> SYSCALL[29628,156]( 15) sys_rt_sigreturn ( ) --> [pre-success] >>> NoWriteResult >>> >>> So, POST(sys_epoll_wait) does not get called and memcheck thinks that the >>> second parameter of epoll_wait is uninitialized. >>> >>> What does this sys_rt_sigreturn mean? Why POST(sys_epoll_wait) is not >>> called? >>> Any idea? >>> >>> Thanks, >>> >>> --kcc >>> >>> >>> >>> >>> >> > |