Messages in this thread |  | | | Date | Wed, 09 Feb 2005 14:05:09 -0600 | | From | Chris Friesen <> | | Subject | [BUG] in copy_siginfo_to_user32 on ppc64 (and others?) in 2.6.9/2.6.10 |
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I found a bug which has since been fixed, but I'm hoping to save others the problems that I had tracking it down.
It was fairly confusing--the information in the siginfo_t struct was different based on whether I used a signal handler in the regular way, or blocked the signal and retrieved the information using sigtimedwait(). After much instrumentation of the kernel, I tracked it down.
Until recently (Jan 5), ppc64 had its own version of compat_sys_rt_sigtimedwait, which simply called sys_rt_sigtimedwait() then copied the results to the userspace struct using copy_siginfo_to_user32().
Unfortunately, sys_rt_sigtimedwait() only copies the lower 16 bits of si_code, and the ppc64 version of copy_siginfo_to_user32() keyed on the upper 16 bits to decide what information to copy. Thus, it always ended up in the default case of the switch statement, and only ever copied si_pid and si_uid.
Oops.
Chris
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