x86/static_call: Add inline static call implementation for x86-64
Add the inline static call implementation for x86-64. The generated code
is identical to the out-of-line case, except we move the trampoline into
it's own section.
Objtool uses the trampoline naming convention to detect all the call
sites. It then annotates those call sites in the .static_call_sites
section.
During boot (and module init), the call sites are patched to call
directly into the destination function. The temporary trampoline is
then no longer used.
[peterz: merged trampolines, put trampoline in section]
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: https://lore.kernel.org/r/20200818135804.864271425@infradead.org
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 595c06b..8a48d3e 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -216,6 +216,7 @@
select HAVE_STACKPROTECTOR if CC_HAS_SANE_STACKPROTECTOR
select HAVE_STACK_VALIDATION if X86_64
select HAVE_STATIC_CALL
+ select HAVE_STATIC_CALL_INLINE if HAVE_STACK_VALIDATION
select HAVE_RSEQ
select HAVE_SYSCALL_TRACEPOINTS
select HAVE_UNSTABLE_SCHED_CLOCK
@@ -231,6 +232,7 @@
select RTC_MC146818_LIB
select SPARSE_IRQ
select SRCU
+ select STACK_VALIDATION if HAVE_STACK_VALIDATION && (HAVE_STATIC_CALL_INLINE || RETPOLINE)
select SYSCTL_EXCEPTION_TRACE
select THREAD_INFO_IN_TASK
select USER_STACKTRACE_SUPPORT
@@ -452,7 +454,6 @@
config RETPOLINE
bool "Avoid speculative indirect branches in kernel"
default y
- select STACK_VALIDATION if HAVE_STACK_VALIDATION
help
Compile kernel with the retpoline compiler options to guard against
kernel-to-user data leaks by avoiding speculative indirect
