x86/lib: Make get/put_user() exception handling a visible symbol

The .L-prefixed exception handling symbols of get_user() and put_user()
do get discarded from the symbol table of the final kernel image.

This confuses tools which parse that symbol table and try to map the
chunk of code to a symbol. And, in general, from toolchain perspective,
it is a good practice to have all code belong to a symbol, and the
correct one at that.

  ( Currently, objdump displays that exception handling chunk as part
    of the previous symbol which is a "fallback" of sorts and not
    correct. )

While at it, rename them to something more descriptive.

  [ bp: Rewrite commit message, rename symbols. ]

Signed-off-by: Nadav Amit <namit@vmware.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Link: https://lore.kernel.org/r/20230525184244.2311-1-namit@vmware.com

diff --git a/arch/x86/lib/getuser.S b/arch/x86/lib/getuser.S
index b64a2bd..9c63713 100644 (file)
--- a/arch/x86/lib/getuser.S
+++ b/arch/x86/lib/getuser.S
@@ -143,43 +143,43 @@ SYM_FUNC_END(__get_user_nocheck_8)
 EXPORT_SYMBOL(__get_user_nocheck_8)
 
 
-SYM_CODE_START_LOCAL(.Lbad_get_user_clac)
+SYM_CODE_START_LOCAL(__get_user_handle_exception)
        ASM_CLAC
 .Lbad_get_user:
        xor %edx,%edx
        mov $(-EFAULT),%_ASM_AX
        RET
-SYM_CODE_END(.Lbad_get_user_clac)
+SYM_CODE_END(__get_user_handle_exception)
 
 #ifdef CONFIG_X86_32
-SYM_CODE_START_LOCAL(.Lbad_get_user_8_clac)
+SYM_CODE_START_LOCAL(__get_user_8_handle_exception)
        ASM_CLAC
 bad_get_user_8:
        xor %edx,%edx
        xor %ecx,%ecx
        mov $(-EFAULT),%_ASM_AX
        RET
-SYM_CODE_END(.Lbad_get_user_8_clac)
+SYM_CODE_END(__get_user_8_handle_exception)
 #endif
 
 /* get_user */
-       _ASM_EXTABLE(1b, .Lbad_get_user_clac)
-       _ASM_EXTABLE(2b, .Lbad_get_user_clac)
-       _ASM_EXTABLE(3b, .Lbad_get_user_clac)
+       _ASM_EXTABLE(1b, __get_user_handle_exception)
+       _ASM_EXTABLE(2b, __get_user_handle_exception)
+       _ASM_EXTABLE(3b, __get_user_handle_exception)
 #ifdef CONFIG_X86_64
-       _ASM_EXTABLE(4b, .Lbad_get_user_clac)
+       _ASM_EXTABLE(4b, __get_user_handle_exception)
 #else
-       _ASM_EXTABLE(4b, .Lbad_get_user_8_clac)
-       _ASM_EXTABLE(5b, .Lbad_get_user_8_clac)
+       _ASM_EXTABLE(4b, __get_user_8_handle_exception)
+       _ASM_EXTABLE(5b, __get_user_8_handle_exception)
 #endif
 
 /* __get_user */
-       _ASM_EXTABLE(6b, .Lbad_get_user_clac)
-       _ASM_EXTABLE(7b, .Lbad_get_user_clac)
-       _ASM_EXTABLE(8b, .Lbad_get_user_clac)
+       _ASM_EXTABLE(6b, __get_user_handle_exception)
+       _ASM_EXTABLE(7b, __get_user_handle_exception)
+       _ASM_EXTABLE(8b, __get_user_handle_exception)
 #ifdef CONFIG_X86_64
-       _ASM_EXTABLE(9b, .Lbad_get_user_clac)
+       _ASM_EXTABLE(9b, __get_user_handle_exception)
 #else
-       _ASM_EXTABLE(9b, .Lbad_get_user_8_clac)
-       _ASM_EXTABLE(10b, .Lbad_get_user_8_clac)
+       _ASM_EXTABLE(9b, __get_user_8_handle_exception)
+       _ASM_EXTABLE(10b, __get_user_8_handle_exception)
 #endif

diff --git a/arch/x86/lib/putuser.S b/arch/x86/lib/putuser.S
index 3062d09..1451e0c 100644 (file)
--- a/arch/x86/lib/putuser.S
+++ b/arch/x86/lib/putuser.S
@@ -131,22 +131,22 @@ SYM_FUNC_START(__put_user_nocheck_8)
 SYM_FUNC_END(__put_user_nocheck_8)
 EXPORT_SYMBOL(__put_user_nocheck_8)
 
-SYM_CODE_START_LOCAL(.Lbad_put_user_clac)
+SYM_CODE_START_LOCAL(__put_user_handle_exception)
        ASM_CLAC
 .Lbad_put_user:
        movl $-EFAULT,%ecx
        RET
-SYM_CODE_END(.Lbad_put_user_clac)
+SYM_CODE_END(__put_user_handle_exception)
 
-       _ASM_EXTABLE(1b, .Lbad_put_user_clac)
-       _ASM_EXTABLE(2b, .Lbad_put_user_clac)
-       _ASM_EXTABLE(3b, .Lbad_put_user_clac)
-       _ASM_EXTABLE(4b, .Lbad_put_user_clac)
-       _ASM_EXTABLE(5b, .Lbad_put_user_clac)
-       _ASM_EXTABLE(6b, .Lbad_put_user_clac)
-       _ASM_EXTABLE(7b, .Lbad_put_user_clac)
-       _ASM_EXTABLE(9b, .Lbad_put_user_clac)
+       _ASM_EXTABLE(1b, __put_user_handle_exception)
+       _ASM_EXTABLE(2b, __put_user_handle_exception)
+       _ASM_EXTABLE(3b, __put_user_handle_exception)
+       _ASM_EXTABLE(4b, __put_user_handle_exception)
+       _ASM_EXTABLE(5b, __put_user_handle_exception)
+       _ASM_EXTABLE(6b, __put_user_handle_exception)
+       _ASM_EXTABLE(7b, __put_user_handle_exception)
+       _ASM_EXTABLE(9b, __put_user_handle_exception)
 #ifdef CONFIG_X86_32
-       _ASM_EXTABLE(8b, .Lbad_put_user_clac)
-       _ASM_EXTABLE(10b, .Lbad_put_user_clac)
+       _ASM_EXTABLE(8b, __put_user_handle_exception)
+       _ASM_EXTABLE(10b, __put_user_handle_exception)
 #endif