x86/extable: Mark exception handler functions visible

Mark the C exception handler functions that are directly called through
exception tables visible. LTO needs to know they are accessed from assembler.

[ tglx: Mopped up the wrecked argument alignment. Sigh.... ]
Signed-off-by: NAndi Kleen <ak@linux.intel.com>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/20171222001821.2157-6-andi@firstfloor.org

arch/x86/mm/extable.c

@@ -21,7 +21,7 @@ ex_fixup_handler(const struct exception_table_entry *x)
 	return (ex_handler_t)((unsigned long)&x->handler + x->handler);
 }
 
-bool ex_handler_default(const struct exception_table_entry *fixup,
+__visible bool ex_handler_default(const struct exception_table_entry *fixup,
 				  struct pt_regs *regs, int trapnr)
 {
 	regs->ip = ex_fixup_addr(fixup);
@@ -29,7 +29,7 @@ bool ex_handler_default(const struct exception_table_entry *fixup,
 }
 EXPORT_SYMBOL(ex_handler_default);
 
-bool ex_handler_fault(const struct exception_table_entry *fixup,
+__visible bool ex_handler_fault(const struct exception_table_entry *fixup,
 				struct pt_regs *regs, int trapnr)
 {
 	regs->ip = ex_fixup_addr(fixup);
@@ -42,7 +42,7 @@ EXPORT_SYMBOL_GPL(ex_handler_fault);
  * Handler for UD0 exception following a failed test against the
  * result of a refcount inc/dec/add/sub.
  */
-bool ex_handler_refcount(const struct exception_table_entry *fixup,
+__visible bool ex_handler_refcount(const struct exception_table_entry *fixup,
 				   struct pt_regs *regs, int trapnr)
 {
 	/* First unconditionally saturate the refcount. */
@@ -95,7 +95,7 @@ EXPORT_SYMBOL(ex_handler_refcount);
  * of vulnerability by restoring from the initial state (essentially, zeroing
  * out all the FPU registers) if we can't restore from the task's FPU state.
  */
-bool ex_handler_fprestore(const struct exception_table_entry *fixup,
+__visible bool ex_handler_fprestore(const struct exception_table_entry *fixup,
 				    struct pt_regs *regs, int trapnr)
 {
 	regs->ip = ex_fixup_addr(fixup);
@@ -108,7 +108,7 @@ bool ex_handler_fprestore(const struct exception_table_entry *fixup,
 }
 EXPORT_SYMBOL_GPL(ex_handler_fprestore);
 
-bool ex_handler_ext(const struct exception_table_entry *fixup,
+__visible bool ex_handler_ext(const struct exception_table_entry *fixup,
 			      struct pt_regs *regs, int trapnr)
 {
 	/* Special hack for uaccess_err */
@@ -118,7 +118,7 @@ bool ex_handler_ext(const struct exception_table_entry *fixup,
 }
 EXPORT_SYMBOL(ex_handler_ext);
 
-bool ex_handler_rdmsr_unsafe(const struct exception_table_entry *fixup,
+__visible bool ex_handler_rdmsr_unsafe(const struct exception_table_entry *fixup,
 				       struct pt_regs *regs, int trapnr)
 {
 	if (pr_warn_once("unchecked MSR access error: RDMSR from 0x%x at rIP: 0x%lx (%pF)\n",
@@ -133,7 +133,7 @@ bool ex_handler_rdmsr_unsafe(const struct exception_table_entry *fixup,
 }
 EXPORT_SYMBOL(ex_handler_rdmsr_unsafe);
 
-bool ex_handler_wrmsr_unsafe(const struct exception_table_entry *fixup,
+__visible bool ex_handler_wrmsr_unsafe(const struct exception_table_entry *fixup,
 				       struct pt_regs *regs, int trapnr)
 {
 	if (pr_warn_once("unchecked MSR access error: WRMSR to 0x%x (tried to write 0x%08x%08x) at rIP: 0x%lx (%pF)\n",
@@ -147,7 +147,7 @@ bool ex_handler_wrmsr_unsafe(const struct exception_table_entry *fixup,
 }
 EXPORT_SYMBOL(ex_handler_wrmsr_unsafe);
 
-bool ex_handler_clear_fs(const struct exception_table_entry *fixup,
+__visible bool ex_handler_clear_fs(const struct exception_table_entry *fixup,
 				   struct pt_regs *regs, int trapnr)
 {
 	if (static_cpu_has(X86_BUG_NULL_SEG))
@@ -157,7 +157,7 @@ bool ex_handler_clear_fs(const struct exception_table_entry *fixup,
 }
 EXPORT_SYMBOL(ex_handler_clear_fs);
 
-bool ex_has_fault_handler(unsigned long ip)
+__visible bool ex_has_fault_handler(unsigned long ip)
 {
 	const struct exception_table_entry *e;
 	ex_handler_t handler;