Messages in this thread Patch in this message | | | Date | Fri, 17 Feb 2006 16:49:57 -0500 | From | Chuck Ebbert <> | Subject | [patch] i386: another possible singlestep fix |
| |
When entering kernel via int80, TIF_SINGLESTEP is not set when TF has been set in eflags by the user. This patch does that.
To make things symmetrical, something further should be done. Either (a) add to this patch so it clears TF after setting TIF_SINGLESTEP, or (b) change the sysenter path so it sets TF in regs.eflags when it finds TIF_SINGLESTEP was set by do_debug() during kernel entry.
Signed-off-by: Chuck Ebbert <76306.1226@compuserve.com>
--- 2.6.16-rc3.orig/arch/i386/kernel/entry.S +++ 2.6.16-rc3/arch/i386/kernel/entry.S @@ -226,6 +226,10 @@ ENTRY(system_call) pushl %eax # save orig_eax SAVE_ALL GET_THREAD_INFO(%ebp) + testl $TF_MASK,EFLAGS(%esp) + jz no_singlestep + orl $_TIF_SINGLESTEP,TI_flags(%ebp) +no_singlestep: # system call tracing in operation / emulation /* Note, _TIF_SECCOMP is bit number 8, and so it needs testw and not testb */ testw $(_TIF_SYSCALL_EMU|_TIF_SYSCALL_TRACE|_TIF_SECCOMP|_TIF_SYSCALL_AUDIT),TI_flags(%ebp) -- Chuck "Equations are the Devil's sentences." --Stephen Colbert - 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/
| |