Red Hat Bugzilla – Bug 145338
attach or detach during nanosleep in 32 bit process returns EINVAL instead of EINTR
Last modified: 2013-03-06 00:58:02 EST
Description of problem: (Component is just a guess) Executing nanosleep from a 32-bit returns wrong value in errno when interrupted by a signal (EINVAL instead of EINTR). For quick reference here is man page description: ==== In case of an error or exception, the nanosleep system call returns -1 instead of 0 and sets errno to one of the following values: EINTR The pause has been interrupted by a non-blocked signal that was delivered to the process. The remaining sleep time has been written into *rem so that the process can easily call nanosleep again and continue with the pause. EINVAL The value in the tv_nsec field was not in the range 0 to 999 999 999 or tv_sec was negative. Version-Release number of selected component (if applicable): How reproducible: Run repro.sh from attached archive. Actual results: errno is EINVAL Expected results: errno should be EINTR Additional info:
Created attachment 109867 [details] repro.c, Makefile and shell script to demonstrate correct 64-bit and errant 32-bit behavior
*** Bug 145337 has been marked as a duplicate of this bug. ***
This is a kernel thing, glibc's nanosleep just issues the nanosleep syscall.
Earlier description is misleading. The crux of the problem is that our debugging methodology revolves around spinning in a loop that pauses briefly in nanosleep so long as a given "spinfile" exists. This allows us to attach a debugger before a given context is lost. The act of attach to a 32 bit process in one of these spin loops exhibits a bug. It appears that some aspect of the attach performs an madvise with a bad 3rd argument (int advice). This seems to leave an corrupted errno containing EINVAL instead of the expected EINTR: madvise(0xffffda10, 4294957576, 0x6b1ff4) = -1 EINVAL (Invalid argument)
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