Messages in this thread Patch in this message | | | Subject | [PATCH] fix broken vm86 interrupt/signal handling | Date | Fri, 19 May 2006 15:09:07 -0700 | From | "Aleksey Gorelov" <> |
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Hi,
This patch www.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h =c3ff8ec31c1249d268cd11390649768a12bec1b9 has broken vm86 interrupt/signal handling in case when vm86 is called from kernel space. In this scenario, if signal is pending because of vm86 interrupt, do_notify_resume/do_signal exits immediately due to user_mode() check, without processing any signals. Thus, resume_userspace handler is spinning in a tight loop with signal pending and TIF_SIGPENDING is set. Previously everything worked Ok.
The following patch fixes the issue
Signed-off-by: Aleksey Gorelov <aleksey_gorelov@phoenix.com>
--- linux-2.6.16/arch/i386/kernel/entry.S-old 2006-05-19 14:31:41.000000000 -0700 +++ linux-2.6.16/arch/i386/kernel/entry.S 2006-05-19 14:33:31.000000000 -0700 @@ -82,6 +82,12 @@ #define resume_kernel restore_nocheck #endif +#ifdef CONFIG_VM86 +#define resume_userspace_sig check_userspace +#else +#define resume_userspace_sig resume_userspace +#endif + #define SAVE_ALL \ cld; \ pushl %es; \ @@ -143,6 +149,7 @@ preempt_stop ret_from_intr: GET_THREAD_INFO(%ebp) +check_userspace: movl EFLAGS(%esp), %eax # mix EFLAGS and CS movb CS(%esp), %al testl $(VM_MASK | 3), %eax @@ -319,7 +326,7 @@ # vm86-space xorl %edx, %edx call do_notify_resume - jmp resume_userspace + jmp resume_userspace_sig ALIGN work_notifysig_v86: @@ -330,7 +337,7 @@ movl %eax, %esp xorl %edx, %edx call do_notify_resume - jmp resume_userspace + jmp resume_userspace_sig #endif # perform syscall exit tracing - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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