From a78ce80d2c9178351b34d78fec805140c29c193e Mon Sep 17 00:00:00 2001 From: Dave Martin Date: Mon, 27 Mar 2017 15:10:55 +0100 Subject: metag/ptrace: Preserve previous registers for short regset write Ensure that if userspace supplies insufficient data to PTRACE_SETREGSET to fill all the registers, the thread's old registers are preserved. Signed-off-by: Dave Martin Acked-by: James Hogan Signed-off-by: Linus Torvalds --- arch/metag/kernel/ptrace.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'arch/metag/kernel/ptrace.c') diff --git a/arch/metag/kernel/ptrace.c b/arch/metag/kernel/ptrace.c index 7563628822bd..ae659ba61948 100644 --- a/arch/metag/kernel/ptrace.c +++ b/arch/metag/kernel/ptrace.c @@ -303,7 +303,7 @@ static int metag_tls_set(struct task_struct *target, const void *kbuf, const void __user *ubuf) { int ret; - void __user *tls; + void __user *tls = target->thread.tls_ptr; ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &tls, 0, -1); if (ret) -- cgit From 5fe81fe98123ce41265c65e95d34418d30d005d1 Mon Sep 17 00:00:00 2001 From: Dave Martin Date: Mon, 27 Mar 2017 15:10:56 +0100 Subject: metag/ptrace: Provide default TXSTATUS for short NT_PRSTATUS Ensure that if userspace supplies insufficient data to PTRACE_SETREGSET to fill TXSTATUS, a well-defined default value is used, based on the task's current value. Suggested-by: James Hogan Signed-off-by: Dave Martin Signed-off-by: Linus Torvalds --- arch/metag/kernel/ptrace.c | 15 ++++++++++++--- 1 file changed, 12 insertions(+), 3 deletions(-) (limited to 'arch/metag/kernel/ptrace.c') diff --git a/arch/metag/kernel/ptrace.c b/arch/metag/kernel/ptrace.c index ae659ba61948..2e4dfc15abd3 100644 --- a/arch/metag/kernel/ptrace.c +++ b/arch/metag/kernel/ptrace.c @@ -24,6 +24,16 @@ * user_regset definitions. */ +static unsigned long user_txstatus(const struct pt_regs *regs) +{ + unsigned long data = (unsigned long)regs->ctx.Flags; + + if (regs->ctx.SaveMask & TBICTX_CBUF_BIT) + data |= USER_GP_REGS_STATUS_CATCH_BIT; + + return data; +} + int metag_gp_regs_copyout(const struct pt_regs *regs, unsigned int pos, unsigned int count, void *kbuf, void __user *ubuf) @@ -62,9 +72,7 @@ int metag_gp_regs_copyout(const struct pt_regs *regs, if (ret) goto out; /* TXSTATUS */ - data = (unsigned long)regs->ctx.Flags; - if (regs->ctx.SaveMask & TBICTX_CBUF_BIT) - data |= USER_GP_REGS_STATUS_CATCH_BIT; + data = user_txstatus(regs); ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, &data, 4*25, 4*26); if (ret) @@ -119,6 +127,7 @@ int metag_gp_regs_copyin(struct pt_regs *regs, if (ret) goto out; /* TXSTATUS */ + data = user_txstatus(regs); ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &data, 4*25, 4*26); if (ret) -- cgit From 7195ee3120d878259e8d94a5d9f808116f34d5ea Mon Sep 17 00:00:00 2001 From: Dave Martin Date: Mon, 27 Mar 2017 15:10:57 +0100 Subject: metag/ptrace: Reject partial NT_METAG_RPIPE writes It's not clear what behaviour is sensible when doing partial write of NT_METAG_RPIPE, so just don't bother. This patch assumes that userspace will never rely on a partial SETREGSET in this case, since it's not clear what should happen anyway. Signed-off-by: Dave Martin Acked-by: James Hogan Signed-off-by: Linus Torvalds --- arch/metag/kernel/ptrace.c | 2 ++ 1 file changed, 2 insertions(+) (limited to 'arch/metag/kernel/ptrace.c') diff --git a/arch/metag/kernel/ptrace.c b/arch/metag/kernel/ptrace.c index 2e4dfc15abd3..5e2dc7defd2c 100644 --- a/arch/metag/kernel/ptrace.c +++ b/arch/metag/kernel/ptrace.c @@ -253,6 +253,8 @@ int metag_rp_state_copyin(struct pt_regs *regs, unsigned long long *ptr; int ret, i; + if (count < 4*13) + return -EINVAL; /* Read the entire pipeline before making any changes */ ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &rp, 0, 4*13); -- cgit