diff options
Diffstat (limited to 'common/recipes-kernel/linux/linux-yocto-4.9.21/0012-x86-mm-kaslr-Use-the-_ASM_MUL-macro-for-multiplicati.patch')
| -rw-r--r-- | common/recipes-kernel/linux/linux-yocto-4.9.21/0012-x86-mm-kaslr-Use-the-_ASM_MUL-macro-for-multiplicati.patch | 75 |
1 files changed, 75 insertions, 0 deletions
diff --git a/common/recipes-kernel/linux/linux-yocto-4.9.21/0012-x86-mm-kaslr-Use-the-_ASM_MUL-macro-for-multiplicati.patch b/common/recipes-kernel/linux/linux-yocto-4.9.21/0012-x86-mm-kaslr-Use-the-_ASM_MUL-macro-for-multiplicati.patch new file mode 100644 index 00000000..bdb55fda --- /dev/null +++ b/common/recipes-kernel/linux/linux-yocto-4.9.21/0012-x86-mm-kaslr-Use-the-_ASM_MUL-macro-for-multiplicati.patch @@ -0,0 +1,75 @@ +From 280488ceca9427dd91e5ee449d90f8cf16d8e65c Mon Sep 17 00:00:00 2001 +From: Matthias Kaehlcke <mka@chromium.org> +Date: Mon, 1 May 2017 15:47:41 -0700 +Subject: [PATCH 12/93] x86/mm/kaslr: Use the _ASM_MUL macro for multiplication + to work around Clang incompatibility + +[ Upstream commit 121843eb02a6e2fa30aefab64bfe183c97230c75 ] + +The constraint "rm" allows the compiler to put mix_const into memory. +When the input operand is a memory location then MUL needs an operand +size suffix, since Clang can't infer the multiplication width from the +operand. + +Add and use the _ASM_MUL macro which determines the operand size and +resolves to the NUL instruction with the corresponding suffix. + +This fixes the following error when building with clang: + + CC arch/x86/lib/kaslr.o + /tmp/kaslr-dfe1ad.s: Assembler messages: + /tmp/kaslr-dfe1ad.s:182: Error: no instruction mnemonic suffix given and no register operands; can't size instruction + +Signed-off-by: Matthias Kaehlcke <mka@chromium.org> +Cc: Grant Grundler <grundler@chromium.org> +Cc: Greg Hackmann <ghackmann@google.com> +Cc: Kees Cook <keescook@chromium.org> +Cc: Linus Torvalds <torvalds@linux-foundation.org> +Cc: Michael Davidson <md@google.com> +Cc: Peter Zijlstra <peterz@infradead.org> +Cc: Thomas Gleixner <tglx@linutronix.de> +Link: http://lkml.kernel.org/r/20170501224741.133938-1-mka@chromium.org +Signed-off-by: Ingo Molnar <mingo@kernel.org> +Signed-off-by: Sasha Levin <alexander.levin@microsoft.com> +Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> +--- + arch/x86/include/asm/asm.h | 1 + + arch/x86/lib/kaslr.c | 3 ++- + 2 files changed, 3 insertions(+), 1 deletion(-) + +diff --git a/arch/x86/include/asm/asm.h b/arch/x86/include/asm/asm.h +index 7bb29a4..08684b3 100644 +--- a/arch/x86/include/asm/asm.h ++++ b/arch/x86/include/asm/asm.h +@@ -34,6 +34,7 @@ + #define _ASM_ADD __ASM_SIZE(add) + #define _ASM_SUB __ASM_SIZE(sub) + #define _ASM_XADD __ASM_SIZE(xadd) ++#define _ASM_MUL __ASM_SIZE(mul) + + #define _ASM_AX __ASM_REG(ax) + #define _ASM_BX __ASM_REG(bx) +diff --git a/arch/x86/lib/kaslr.c b/arch/x86/lib/kaslr.c +index 121f59c..0c7fe44 100644 +--- a/arch/x86/lib/kaslr.c ++++ b/arch/x86/lib/kaslr.c +@@ -5,6 +5,7 @@ + * kernel starts. This file is included in the compressed kernel and + * normally linked in the regular. + */ ++#include <asm/asm.h> + #include <asm/kaslr.h> + #include <asm/msr.h> + #include <asm/archrandom.h> +@@ -79,7 +80,7 @@ unsigned long kaslr_get_random_long(const char *purpose) + } + + /* Circular multiply for better bit diffusion */ +- asm("mul %3" ++ asm(_ASM_MUL "%3" + : "=a" (random), "=d" (raw) + : "a" (random), "rm" (mix_const)); + random += raw; +-- +2.7.4 + |