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ARM: 8772/1: kprobes: Prohibit kprobes on get_user functions 

Since do_undefinstr() uses get_user to get the undefined
instruction, it can be called before kprobes processes
recursive check. This can cause an infinit recursive
exception.
Prohibit probing on get_user functions.

Fixes: 24ba613c9d ("ARM kprobes: core code")
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Cc: stable@vger.kernel.org
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
hifive-unleashed-5.1
Masami Hiramatsu 2018-05-13 05:04:29 +01:00 committed by Russell King
parent eb0146daef
commit 0d73c3f8e7
2 changed files with 20 additions and 0 deletions
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10
arch/arm/include/asm/assembler.h
View File

@ -536,4 +536,14 @@ THUMB( orr \reg , \reg , #PSR_T_BIT )
#endif
.endm
#ifdef CONFIG_KPROBES
#define _ASM_NOKPROBE(entry) \
.pushsection "_kprobe_blacklist", "aw" ; \
.balign 4 ; \
.long entry; \
.popsection
#else
#define _ASM_NOKPROBE(entry)
#endif
#endif /* __ASM_ASSEMBLER_H__ */

10
arch/arm/lib/getuser.S
View File

@ -38,6 +38,7 @@ ENTRY(__get_user_1)
mov r0, #0
ret lr
ENDPROC(__get_user_1)
_ASM_NOKPROBE(__get_user_1)
ENTRY(__get_user_2)
check_uaccess r0, 2, r1, r2, __get_user_bad
@ -58,6 +59,7 @@ rb .req r0
mov r0, #0
ret lr
ENDPROC(__get_user_2)
_ASM_NOKPROBE(__get_user_2)
ENTRY(__get_user_4)
check_uaccess r0, 4, r1, r2, __get_user_bad
@ -65,6 +67,7 @@ ENTRY(__get_user_4)
mov r0, #0
ret lr
ENDPROC(__get_user_4)
_ASM_NOKPROBE(__get_user_4)
ENTRY(__get_user_8)
check_uaccess r0, 8, r1, r2, __get_user_bad8
@ -78,6 +81,7 @@ ENTRY(__get_user_8)
mov r0, #0
ret lr
ENDPROC(__get_user_8)
_ASM_NOKPROBE(__get_user_8)
#ifdef __ARMEB__
ENTRY(__get_user_32t_8)
@ -91,6 +95,7 @@ ENTRY(__get_user_32t_8)
mov r0, #0
ret lr
ENDPROC(__get_user_32t_8)
_ASM_NOKPROBE(__get_user_32t_8)
ENTRY(__get_user_64t_1)
check_uaccess r0, 1, r1, r2, __get_user_bad8
@ -98,6 +103,7 @@ ENTRY(__get_user_64t_1)
mov r0, #0
ret lr
ENDPROC(__get_user_64t_1)
_ASM_NOKPROBE(__get_user_64t_1)
ENTRY(__get_user_64t_2)
check_uaccess r0, 2, r1, r2, __get_user_bad8
@ -114,6 +120,7 @@ rb .req r0
mov r0, #0
ret lr
ENDPROC(__get_user_64t_2)
_ASM_NOKPROBE(__get_user_64t_2)
ENTRY(__get_user_64t_4)
check_uaccess r0, 4, r1, r2, __get_user_bad8
@ -121,6 +128,7 @@ ENTRY(__get_user_64t_4)
mov r0, #0
ret lr
ENDPROC(__get_user_64t_4)
_ASM_NOKPROBE(__get_user_64t_4)
#endif
__get_user_bad8:
@ -131,6 +139,8 @@ __get_user_bad:
ret lr
ENDPROC(__get_user_bad)
ENDPROC(__get_user_bad8)
_ASM_NOKPROBE(__get_user_bad)
_ASM_NOKPROBE(__get_user_bad8)
.pushsection __ex_table, "a"
.long 1b, __get_user_bad