On Wed, Mar 25, 2015 at 07:20:28PM +0100, Denys Vlasenko wrote: > A named label "ret_from_sys_call" implies that there are jumps > to this location from elsewhere, as happens with many other labels > in this file. > But this label is used only by the JMP a few insns above. > To make that obvious, use local numeric label instead. > > Do the same in the second copy of the syscall table dispatch code, > it has a similar JMP which skips the CALL. > > Improve comments: > > "and return regs->ax" isn't too informative. We always return regs->ax. > > The comment suggesting that it'd be cool to use rip relative addressing for > CALL > is deleted. It's unclear why that would be an improvement - we aren't striving > to use position-independent code here. PIC code here would require something > like > LEA sys_call_table(%rip),reg + CALL *(reg,%rax*8)... > > "iret frame is also incomplete" is no longer true, fix that too. > > Signed-off-by: Denys Vlasenko <[email protected]> > CC: Linus Torvalds <[email protected]> > CC: Steven Rostedt <[email protected]> > CC: Ingo Molnar <[email protected]> > CC: Borislav Petkov <[email protected]> > CC: "H. Peter Anvin" <[email protected]> > CC: Andy Lutomirski <[email protected]> > CC: Oleg Nesterov <[email protected]> > CC: Frederic Weisbecker <[email protected]> > CC: Alexei Starovoitov <[email protected]> > CC: Will Drewry <[email protected]> > CC: Kees Cook <[email protected]> > CC: [email protected] > CC: [email protected] > --- > > Changes in v2: gave "jmp 1f" treatment to the second jump. > > arch/x86/kernel/entry_64.S | 15 ++++++++------- > 1 file changed, 8 insertions(+), 7 deletions(-)
Acked-by: Borislav Petkov <[email protected]> -- Regards/Gruss, Boris. ECO tip #101: Trim your mails when you reply. -- -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
