This is a note to let you know that I've just added the patch titled
x86/retpoline: Avoid retpolines for built-in __init functions
to the 4.14-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git%3Ba=su...
The filename of the patch is: x86retpoline_Avoid_retpolines_for_built-in___init_functions.patch and it can be found in the queue-4.14 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree, please let stable@vger.kernel.org know about it.
Subject: x86/retpoline: Avoid retpolines for built-in __init functions From: David Woodhouse dwmw@amazon.co.uk Date: Thu Feb 1 11:27:20 2018 +0000
From: David Woodhouse dwmw@amazon.co.uk
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: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- include/linux/init.h | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-)
--- a/include/linux/init.h +++ b/include/linux/init.h @@ -5,6 +5,13 @@ #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 @@ -40,7 +47,7 @@
/* These are for everybody (although not all archs will actually discard it in modules) */ -#define __init __section(.init.text) __cold __inittrace __latent_entropy +#define __init __section(.init.text) __cold __inittrace __latent_entropy __noretpoline #define __initdata __section(.init.data) #define __initconst __section(.init.rodata) #define __exitdata __section(.exit.data)
Patches currently in stable-queue which might be from dwmw@amazon.co.uk are
queue-4.14/x86spectre_Simplify_spectre_v2_command_line_parsing.patch queue-4.14/x86pti_Mark_constant_arrays_as___initconst.patch queue-4.14/x86pti_Do_not_enable_PTI_on_CPUs_which_are_not_vulnerable_to_Meltdown.patch queue-4.14/x86speculation_Use_Indirect_Branch_Prediction_Barrier_in_context_switch.patch queue-4.14/x86cpuid_Fix_up_virtual_IBRSIBPBSTIBP_feature_bits_on_Intel.patch queue-4.14/x86spectre_Fix_spelling_mistake_vunerable-_vulnerable.patch queue-4.14/x86cpufeature_Blacklist_SPEC_CTRLPRED_CMD_on_early_Spectre_v2_microcodes.patch queue-4.14/x86cpufeatures_Add_Intel_feature_bits_for_Speculation_Control.patch queue-4.14/KVM_VMX_Make_indirect_call_speculation_safe.patch queue-4.14/x86spectre_Check_CONFIG_RETPOLINE_in_command_line_parser.patch queue-4.14/x86msr_Add_definitions_for_new_speculation_control_MSRs.patch queue-4.14/KVMVMX_Allow_direct_access_to_MSR_IA32_SPEC_CTRL.patch queue-4.14/x86cpufeatures_Add_CPUID_7_EDX_CPUID_leaf.patch queue-4.14/x86retpoline_Remove_the_esprsp_thunk.patch queue-4.14/x86cpufeatures_Add_AMD_feature_bits_for_Speculation_Control.patch queue-4.14/KVMSVM_Allow_direct_access_to_MSR_IA32_SPEC_CTRL.patch queue-4.14/KVMx86_Add_IBPB_support.patch queue-4.14/KVMVMX_Emulate_MSR_IA32_ARCH_CAPABILITIES.patch queue-4.14/x86speculation_Add_basic_IBPB_(Indirect_Branch_Prediction_Barrier)_support.patch queue-4.14/x86speculation_Simplify_indirect_branch_prediction_barrier().patch queue-4.14/x86speculation_Fix_typo_IBRS_ATT_which_should_be_IBRS_ALL.patch queue-4.14/KVM_x86_Make_indirect_calls_in_emulator_speculation_safe.patch queue-4.14/x86retpoline_Simplify_vmexit_fill_RSB().patch queue-4.14/x86cpufeatures_Clean_up_Spectre_v2_related_CPUID_flags.patch queue-4.14/KVMx86_Update_the_reverse_cpuid_list_to_include_CPUID_7_EDX.patch queue-4.14/x86retpoline_Avoid_retpolines_for_built-in___init_functions.patch