From: Paolo 'Blaisorblade' Giarrusso Date: Sat, 3 Sep 2005 22:57:22 +0000 (-0700) Subject: [PATCH] uml: SYSEMU: slight cleanup and speedup X-Git-Tag: v2.6.14-rc1~813 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=640aa46e25922a00b805e6b0d0b5181ad9cf736a;p=platform%2Fkernel%2Flinux-exynos.git [PATCH] uml: SYSEMU: slight cleanup and speedup As a follow-up to "UML Support - Ptrace: adds the host SYSEMU support, for UML and general usage" (i.e. uml-support-* in current mm). Avoid unconditionally jumping to work_pending and code copying, just reuse the already existing resume_userspace path. One interesting note, from Charles P. Wright, suggested that the API is improvable with no downsides for UML (except that it will have to support yet another host API, since dropping support for the current API, for UML, is not reasonable from users' point of view). Signed-off-by: Paolo 'Blaisorblade' Giarrusso CC: Charles P. Wright Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- diff --git a/arch/i386/kernel/entry.S b/arch/i386/kernel/entry.S index 9a47723..abb9097 100644 --- a/arch/i386/kernel/entry.S +++ b/arch/i386/kernel/entry.S @@ -339,18 +339,12 @@ syscall_trace_entry: xorl %edx,%edx call do_syscall_trace cmpl $0, %eax - jne syscall_skip # ret != 0 -> running under PTRACE_SYSEMU, + jne resume_userspace # ret != 0 -> running under PTRACE_SYSEMU, # so must skip actual syscall movl ORIG_EAX(%esp), %eax cmpl $(nr_syscalls), %eax jnae syscall_call jmp syscall_exit -syscall_skip: - cli # make sure we don't miss an interrupt - # setting need_resched or sigpending - # between sampling and the iret - movl TI_flags(%ebp), %ecx - jmp work_pending # perform syscall exit tracing ALIGN