[tip:x86/cleanups] x86/extable: Mark exception handler functions visible

From: tip-bot for Andi Kleen
Date: Sun Jan 14 2018 - 14:11:42 EST


Commit-ID: 80a3e3949b8f3a3efa853d8752fd7ed5ec02de2d
Gitweb: https://git.kernel.org/tip/80a3e3949b8f3a3efa853d8752fd7ed5ec02de2d
Author: Andi Kleen <ak@xxxxxxxxxxxxxxx>
AuthorDate: Thu, 21 Dec 2017 16:18:20 -0800
Committer: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
CommitDate: Sun, 14 Jan 2018 20:04:16 +0100

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: Andi Kleen <ak@xxxxxxxxxxxxxxx>
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Link: https://lkml.kernel.org/r/20171222001821.2157-6-andi@xxxxxxxxxxxxxx
---
arch/x86/mm/extable.c | 34 +++++++++++++++++-----------------
1 file changed, 17 insertions(+), 17 deletions(-)

diff --git a/arch/x86/mm/extable.c b/arch/x86/mm/extable.c
index 9fe656c..45f5d6c 100644
--- a/arch/x86/mm/extable.c
+++ b/arch/x86/mm/extable.c
@@ -21,16 +21,16 @@ 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,
- struct pt_regs *regs, int trapnr)
+__visible bool ex_handler_default(const struct exception_table_entry *fixup,
+ struct pt_regs *regs, int trapnr)
{
regs->ip = ex_fixup_addr(fixup);
return true;
}
EXPORT_SYMBOL(ex_handler_default);

-bool ex_handler_fault(const struct exception_table_entry *fixup,
- struct pt_regs *regs, int trapnr)
+__visible bool ex_handler_fault(const struct exception_table_entry *fixup,
+ struct pt_regs *regs, int trapnr)
{
regs->ip = ex_fixup_addr(fixup);
regs->ax = trapnr;
@@ -42,8 +42,8 @@ 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,
- struct pt_regs *regs, int trapnr)
+__visible bool ex_handler_refcount(const struct exception_table_entry *fixup,
+ struct pt_regs *regs, int trapnr)
{
/* First unconditionally saturate the refcount. */
*(int *)regs->cx = INT_MIN / 2;
@@ -95,8 +95,8 @@ 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,
- struct pt_regs *regs, int trapnr)
+__visible bool ex_handler_fprestore(const struct exception_table_entry *fixup,
+ struct pt_regs *regs, int trapnr)
{
regs->ip = ex_fixup_addr(fixup);

@@ -108,8 +108,8 @@ 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,
- struct pt_regs *regs, int trapnr)
+__visible bool ex_handler_ext(const struct exception_table_entry *fixup,
+ struct pt_regs *regs, int trapnr)
{
/* Special hack for uaccess_err */
current->thread.uaccess_err = 1;
@@ -118,8 +118,8 @@ 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,
- struct pt_regs *regs, int trapnr)
+__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",
(unsigned int)regs->cx, regs->ip, (void *)regs->ip))
@@ -133,8 +133,8 @@ 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,
- struct pt_regs *regs, int trapnr)
+__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",
(unsigned int)regs->cx, (unsigned int)regs->dx,
@@ -147,8 +147,8 @@ 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,
- struct pt_regs *regs, int trapnr)
+__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))
asm volatile ("mov %0, %%fs" : : "rm" (__USER_DS));
@@ -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;