Date: Thu, 22 Feb 2001 11:35:21 -0800 (PST) From: John Baldwin <jhb@FreeBSD.org> To: cvs-committers@FreeBSD.org, cvs-all@FreeBSD.org Subject: cvs commit: src/sys/i386/i386 trap.c Message-ID: <200102221935.f1MJZLx89084@freefall.freebsd.org>
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jhb 2001/02/22 11:35:21 PST Modified files: sys/i386/i386 trap.c Log: The p_md.md_regs member of proc is used in signal handling to reference the the original trapframe of the syscall, trap, or interrupt that entered the kernel. Before SMPng, ast's were handled via a psuedo trap at the end of doerti. With the SMPng commit, ast's were broken out into a separate ast() function that was called from doreti to match the behavior of other architectures. Unfortunately, when this was done, the p_md.md_regs member of curproc was not updateda in ast(), thus when signals are handled by userret() after an interrupt that returns to userland, we end up using a stale trapframe that will result in the registers from the old trapframe overwriting the real trapframe and smashing all the registers right before we return to usermode. The saved %cs:%eip from where we were in usermode are saved in the trapframe for example. Revision Changes Path 1.181 +2 -1 src/sys/i386/i386/trap.c To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe cvs-all" in the body of the message
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