diff options
Diffstat (limited to 'common/recipes-kernel/linux/linux-yocto-4.9.21/0037-x86-retpoline-Avoid-retpolines-for-built-in-__init-f.patch')
| -rw-r--r-- | common/recipes-kernel/linux/linux-yocto-4.9.21/0037-x86-retpoline-Avoid-retpolines-for-built-in-__init-f.patch | 54 |
1 files changed, 54 insertions, 0 deletions
diff --git a/common/recipes-kernel/linux/linux-yocto-4.9.21/0037-x86-retpoline-Avoid-retpolines-for-built-in-__init-f.patch b/common/recipes-kernel/linux/linux-yocto-4.9.21/0037-x86-retpoline-Avoid-retpolines-for-built-in-__init-f.patch new file mode 100644 index 00000000..846ec86f --- /dev/null +++ b/common/recipes-kernel/linux/linux-yocto-4.9.21/0037-x86-retpoline-Avoid-retpolines-for-built-in-__init-f.patch @@ -0,0 +1,54 @@ +From 72e87893e6f14922dcd6231a7676bac67154dae8 Mon Sep 17 00:00:00 2001 +From: David Woodhouse <dwmw@amazon.co.uk> +Date: Thu, 1 Feb 2018 11:27:20 +0000 +Subject: [PATCH 37/42] x86/retpoline: Avoid retpolines for built-in __init + functions + +(cherry picked from commit 66f793099a636862a71c59d4a6ba91387b155e0c) + +There's no point in building init code with retpolines, since it runs before +any potentially hostile userspace does. And before the retpoline is actually +ALTERNATIVEd into place, for much of it. + +Signed-off-by: David Woodhouse <dwmw@amazon.co.uk> +Signed-off-by: Thomas Gleixner <tglx@linutronix.de> +Cc: karahmed@amazon.de +Cc: peterz@infradead.org +Cc: bp@alien8.de +Link: https://lkml.kernel.org/r/1517484441-1420-2-git-send-email-dwmw@amazon.co.uk +Signed-off-by: David Woodhouse <dwmw@amazon.co.uk> +Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> +--- + include/linux/init.h | 9 ++++++++- + 1 file changed, 8 insertions(+), 1 deletion(-) + +diff --git a/include/linux/init.h b/include/linux/init.h +index e30104c..8e346d1 100644 +--- a/include/linux/init.h ++++ b/include/linux/init.h +@@ -4,6 +4,13 @@ + #include <linux/compiler.h> + #include <linux/types.h> + ++/* Built-in __init functions needn't be compiled with retpoline */ ++#if defined(RETPOLINE) && !defined(MODULE) ++#define __noretpoline __attribute__((indirect_branch("keep"))) ++#else ++#define __noretpoline ++#endif ++ + /* These macros are used to mark some functions or + * initialized data (doesn't apply to uninitialized data) + * as `initialization' functions. The kernel can take this +@@ -39,7 +46,7 @@ + + /* These are for everybody (although not all archs will actually + discard it in modules) */ +-#define __init __section(.init.text) __cold notrace __latent_entropy ++#define __init __section(.init.text) __cold notrace __latent_entropy __noretpoline + #define __initdata __section(.init.data) + #define __initconst __section(.init.rodata) + #define __exitdata __section(.exit.data) +-- +2.7.4 + |