Date: Sat, 9 Oct 2004 17:10:48 +0000 (UTC) From: David Schultz <das@FreeBSD.org> To: src-committers@FreeBSD.org, cvs-src@FreeBSD.org, cvs-all@FreeBSD.org Subject: cvs commit: src/sys/i386/linux linux_ptrace.c Message-ID: <200410091710.i99HAmMN011788@repoman.freebsd.org>
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das 2004-10-09 17:10:48 UTC
FreeBSD src repository
Modified files: (Branch: RELENG_5)
sys/i386/linux linux_ptrace.c
Log:
MFC src/sys/i386/linux/linux_ptrace.c, v1.14
| Fix the following race:
|
| 1. Process p1 is currently being swapped in.
| 2. Process p2 calls linux_ptrace(PTRACE_GETFPXREGS, p1_pid, ...)
| 3. After acquiring a reference to FIRST_THREAD_IN_PROC(p1),
| p2 blocks in faultin() while p1 finishes being swapped in.
| This means p2 won't get back the lock on p1 until after p1's
| threads are runnable.
| 4. After p1 is swapped in, the first thread in p1 exits.
| 5. p2 now uses its dangling reference to p1's first thread.
Approved by: re (scottl)
Revision Changes Path
1.13.2.1 +4 -3 src/sys/i386/linux/linux_ptrace.c
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