3.13.11-ckt25 -stable review patch. If anyone has any objections, please let me know.
------------------ From: Denys Vlasenko <dvlas...@redhat.com> commit 0784b36448a2a85b95b6eb21a69b9045c896c065 upstream. No code changes. Signed-off-by: Denys Vlasenko <dvlas...@redhat.com> Acked-by: Borislav Petkov <b...@suse.de> Cc: Alexei Starovoitov <a...@plumgrid.com> Cc: Andy Lutomirski <l...@amacapital.net> Cc: Borislav Petkov <b...@alien8.de> Cc: Frederic Weisbecker <fweis...@gmail.com> Cc: H. Peter Anvin <h...@zytor.com> Cc: Kees Cook <keesc...@chromium.org> Cc: Linus Torvalds <torva...@linux-foundation.org> Cc: Oleg Nesterov <o...@redhat.com> Cc: Steven Rostedt <rost...@goodmis.org> Cc: Will Drewry <w...@chromium.org> Link: http://lkml.kernel.org/r/1427899858-7165-1-git-send-email-dvlas...@redhat.com Signed-off-by: Ingo Molnar <mi...@kernel.org> Signed-off-by: Ben Hutchings <b...@decadent.org.uk> Acked-by: John Johansen <john.johan...@canonical.com> Acked-by: Andy Whitcroft <a...@canonical.com> Signed-off-by: Luis Henriques <luis.henriq...@canonical.com> Signed-off-by: Andy Whitcroft <a...@canonical.com> Signed-off-by: Kamal Mostafa <ka...@canonical.com> --- arch/x86/kernel/entry_64.S | 28 +++++++++++++--------------- 1 file changed, 13 insertions(+), 15 deletions(-) diff --git a/arch/x86/kernel/entry_64.S b/arch/x86/kernel/entry_64.S index 082d3ce..f4c0444 100644 --- a/arch/x86/kernel/entry_64.S +++ b/arch/x86/kernel/entry_64.S @@ -1706,19 +1706,7 @@ ENTRY(error_exit) CFI_ENDPROC END(error_exit) -/* - * Test if a given stack is an NMI stack or not. - */ - .macro test_in_nmi reg stack nmi_ret normal_ret - cmpq %\reg, \stack - ja \normal_ret - subq $EXCEPTION_STKSZ, %\reg - cmpq %\reg, \stack - jb \normal_ret - jmp \nmi_ret - .endm - - /* runs on exception stack */ +/* Runs on exception stack */ ENTRY(nmi) INTR_FRAME PARAVIRT_ADJUST_EXCEPTION_FRAME @@ -1779,8 +1767,18 @@ ENTRY(nmi) * We check the variable because the first NMI could be in a * breakpoint routine using a breakpoint stack. */ - lea 6*8(%rsp), %rdx - test_in_nmi rdx, 4*8(%rsp), nested_nmi, first_nmi + lea 6*8(%rsp), %rdx + /* Compare the NMI stack (rdx) with the stack we came from (4*8(%rsp)) */ + cmpq %rdx, 4*8(%rsp) + /* If the stack pointer is above the NMI stack, this is a normal NMI */ + ja first_nmi + subq $EXCEPTION_STKSZ, %rdx + cmpq %rdx, 4*8(%rsp) + /* If it is below the NMI stack, it is a normal NMI */ + jb first_nmi + /* Ah, it is within the NMI stack, treat it as nested */ + jmp nested_nmi + CFI_REMEMBER_STATE nested_nmi: -- 1.9.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
