diff options
Diffstat (limited to 'common/recipes-kernel/linux/linux-yocto-4.9.21/0010-kaiser-fix-regs-to-do_nmi-ifndef-CONFIG_KAISER.patch')
| -rw-r--r-- | common/recipes-kernel/linux/linux-yocto-4.9.21/0010-kaiser-fix-regs-to-do_nmi-ifndef-CONFIG_KAISER.patch | 74 |
1 files changed, 74 insertions, 0 deletions
diff --git a/common/recipes-kernel/linux/linux-yocto-4.9.21/0010-kaiser-fix-regs-to-do_nmi-ifndef-CONFIG_KAISER.patch b/common/recipes-kernel/linux/linux-yocto-4.9.21/0010-kaiser-fix-regs-to-do_nmi-ifndef-CONFIG_KAISER.patch new file mode 100644 index 00000000..f8e7874d --- /dev/null +++ b/common/recipes-kernel/linux/linux-yocto-4.9.21/0010-kaiser-fix-regs-to-do_nmi-ifndef-CONFIG_KAISER.patch @@ -0,0 +1,74 @@ +From 3d8ca014b31b43c78d3240b2574670f2ab38519c Mon Sep 17 00:00:00 2001 +From: Hugh Dickins <hughd@google.com> +Date: Thu, 21 Sep 2017 20:39:56 -0700 +Subject: [PATCH 010/102] kaiser: fix regs to do_nmi() ifndef CONFIG_KAISER + +pjt has observed that nmi's second (nmi_from_kernel) call to do_nmi() +adjusted the %rdi regs arg, rightly when CONFIG_KAISER, but wrongly +when not CONFIG_KAISER. + +Although the minimal change is to add an #ifdef CONFIG_KAISER around +the addq line, that looks cluttered, and I prefer how the first call +to do_nmi() handled it: prepare args in %rdi and %rsi before getting +into the CONFIG_KAISER block, since it does not touch them at all. + +And while we're here, place the "#ifdef CONFIG_KAISER" that follows +each, to enclose the "Unconditionally restore CR3" comment: matching +how the "Unconditionally use kernel CR3" comment above is enclosed. + +Signed-off-by: Hugh Dickins <hughd@google.com> +Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> +--- + arch/x86/entry/entry_64.S | 11 ++++++----- + 1 file changed, 6 insertions(+), 5 deletions(-) + +diff --git a/arch/x86/entry/entry_64.S b/arch/x86/entry/entry_64.S +index d84e3a7..57f7993 100644 +--- a/arch/x86/entry/entry_64.S ++++ b/arch/x86/entry/entry_64.S +@@ -1321,12 +1321,13 @@ ENTRY(nmi) + movq %rax, %cr3 + #endif + call do_nmi ++ ++#ifdef CONFIG_KAISER + /* + * Unconditionally restore CR3. I know we return to + * kernel code that needs user CR3, but do we ever return + * to "user mode" where we need the kernel CR3? + */ +-#ifdef CONFIG_KAISER + popq %rax + mov %rax, %cr3 + #endif +@@ -1550,6 +1551,8 @@ end_repeat_nmi: + SWAPGS + xorl %ebx, %ebx + 1: ++ movq %rsp, %rdi ++ movq $-1, %rsi + #ifdef CONFIG_KAISER + /* Unconditionally use kernel CR3 for do_nmi() */ + /* %rax is saved above, so OK to clobber here */ +@@ -1562,16 +1565,14 @@ end_repeat_nmi: + #endif + + /* paranoidentry do_nmi, 0; without TRACE_IRQS_OFF */ +- movq %rsp, %rdi +- addq $8, %rdi /* point %rdi at ptregs, fixed up for CR3 */ +- movq $-1, %rsi + call do_nmi ++ ++#ifdef CONFIG_KAISER + /* + * Unconditionally restore CR3. We might be returning to + * kernel code that needs user CR3, like just just before + * a sysret. + */ +-#ifdef CONFIG_KAISER + popq %rax + mov %rax, %cr3 + #endif +-- +2.7.4 + |