[S390] add missing .set function for NT_S390_LAST_BREAK regset (b934069c) · Commits · 戴 / test

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 <schwidefsky@de.ibm.com> Cc: stable@kernel.org

arch/s390/kernel/ptrace.c

+18 −0

Original line number	Diff line number	Diff line
		@@ -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,

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