diff options
Diffstat (limited to 'common/recipes-kernel/linux/linux-yocto-4.9.21/0026-x86-Implement-array_index_mask_nospec.patch')
| -rw-r--r-- | common/recipes-kernel/linux/linux-yocto-4.9.21/0026-x86-Implement-array_index_mask_nospec.patch | 68 |
1 files changed, 0 insertions, 68 deletions
diff --git a/common/recipes-kernel/linux/linux-yocto-4.9.21/0026-x86-Implement-array_index_mask_nospec.patch b/common/recipes-kernel/linux/linux-yocto-4.9.21/0026-x86-Implement-array_index_mask_nospec.patch deleted file mode 100644 index 3731f5b0..00000000 --- a/common/recipes-kernel/linux/linux-yocto-4.9.21/0026-x86-Implement-array_index_mask_nospec.patch +++ /dev/null @@ -1,68 +0,0 @@ -From bc71a58ec0aadad07a49878204eb38273f0c1b9e Mon Sep 17 00:00:00 2001 -From: Dan Williams <dan.j.williams@intel.com> -Date: Mon, 29 Jan 2018 17:02:28 -0800 -Subject: [PATCH 26/42] x86: Implement array_index_mask_nospec - -(cherry picked from commit babdde2698d482b6c0de1eab4f697cf5856c5859) - -array_index_nospec() uses a mask to sanitize user controllable array -indexes, i.e. generate a 0 mask if 'index' >= 'size', and a ~0 mask -otherwise. While the default array_index_mask_nospec() handles the -carry-bit from the (index - size) result in software. - -The x86 array_index_mask_nospec() does the same, but the carry-bit is -handled in the processor CF flag without conditional instructions in the -control flow. - -Suggested-by: Linus Torvalds <torvalds@linux-foundation.org> -Signed-off-by: Dan Williams <dan.j.williams@intel.com> -Signed-off-by: Thomas Gleixner <tglx@linutronix.de> -Cc: linux-arch@vger.kernel.org -Cc: kernel-hardening@lists.openwall.com -Cc: gregkh@linuxfoundation.org -Cc: alan@linux.intel.com -Link: https://lkml.kernel.org/r/151727414808.33451.1873237130672785331.stgit@dwillia2-desk3.amr.corp.intel.com -Signed-off-by: David Woodhouse <dwmw@amazon.co.uk> -Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> ---- - arch/x86/include/asm/barrier.h | 24 ++++++++++++++++++++++++ - 1 file changed, 24 insertions(+) - -diff --git a/arch/x86/include/asm/barrier.h b/arch/x86/include/asm/barrier.h -index bfb28ca..ca22173 100644 ---- a/arch/x86/include/asm/barrier.h -+++ b/arch/x86/include/asm/barrier.h -@@ -23,6 +23,30 @@ - #define wmb() asm volatile("sfence" ::: "memory") - #endif - -+/** -+ * array_index_mask_nospec() - generate a mask that is ~0UL when the -+ * bounds check succeeds and 0 otherwise -+ * @index: array element index -+ * @size: number of elements in array -+ * -+ * Returns: -+ * 0 - (index < size) -+ */ -+static inline unsigned long array_index_mask_nospec(unsigned long index, -+ unsigned long size) -+{ -+ unsigned long mask; -+ -+ asm ("cmp %1,%2; sbb %0,%0;" -+ :"=r" (mask) -+ :"r"(size),"r" (index) -+ :"cc"); -+ return mask; -+} -+ -+/* Override the default implementation from linux/nospec.h. */ -+#define array_index_mask_nospec array_index_mask_nospec -+ - #ifdef CONFIG_X86_PPRO_FENCE - #define dma_rmb() rmb() - #else --- -2.7.4 - |