From b934069c991355d27a053a932591c77960f4e414 Mon Sep 17 00:00:00 2001 From: Martin Schwidefsky Date: Thu, 1 Dec 2011 13:32:17 +0100 Subject: [PATCH] [S390] add missing .set function for NT_S390_LAST_BREAK regset The last breaking event address is a read-only value, the regset misses the .set function. If a PTRACE_SETREGSET is done for NT_S390_LAST_BREAK we get an oops due to a branch to zero: Kernel BUG at 0000000000000002 verbose debug info unavailable illegal operation: 0001 #1 SMP ... Call Trace: (<0000000000158294> ptrace_regset+0x184/0x188) <00000000001595b6> ptrace_request+0x37a/0x4fc <0000000000109a78> arch_ptrace+0x108/0x1fc <00000000001590d6> SyS_ptrace+0xaa/0x12c <00000000005c7a42> sysc_noemu+0x16/0x1c <000003fffd5ec10c> 0x3fffd5ec10c Last Breaking-Event-Address: <0000000000158242> ptrace_regset+0x132/0x188 Add a nop .set function to prevent the branch to zero. Signed-off-by: Martin Schwidefsky Cc: stable@kernel.org --- arch/s390/kernel/ptrace.c | 18 ++++++++++++++++++ 1 file changed, 18 insertions(+) diff --git a/arch/s390/kernel/ptrace.c b/arch/s390/kernel/ptrace.c index 450931a45b68..f05649fd0547 100644 --- a/arch/s390/kernel/ptrace.c +++ b/arch/s390/kernel/ptrace.c @@ -905,6 +905,14 @@ static int s390_last_break_get(struct task_struct *target, return 0; } +static int s390_last_break_set(struct task_struct *target, + const struct user_regset *regset, + unsigned int pos, unsigned int count, + const void *kbuf, const void __user *ubuf) +{ + return 0; +} + #endif static int s390_system_call_get(struct task_struct *target, @@ -951,6 +959,7 @@ static const struct user_regset s390_regsets[] = { .size = sizeof(long), .align = sizeof(long), .get = s390_last_break_get, + .set = s390_last_break_set, }, #endif [REGSET_SYSTEM_CALL] = { @@ -1116,6 +1125,14 @@ static int s390_compat_last_break_get(struct task_struct *target, return 0; } +static int s390_compat_last_break_set(struct task_struct *target, + const struct user_regset *regset, + unsigned int pos, unsigned int count, + const void *kbuf, const void __user *ubuf) +{ + return 0; +} + static const struct user_regset s390_compat_regsets[] = { [REGSET_GENERAL] = { .core_note_type = NT_PRSTATUS, @@ -1139,6 +1156,7 @@ static const struct user_regset s390_compat_regsets[] = { .size = sizeof(long), .align = sizeof(long), .get = s390_compat_last_break_get, + .set = s390_compat_last_break_set, }, [REGSET_SYSTEM_CALL] = { .core_note_type = NT_S390_SYSTEM_CALL, -- 2.34.1