diff options
| author | Guo Ren <guoren@linux.alibaba.com> | 2021-09-24 15:33:38 +0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2021-10-20 11:40:12 +0200 |
| commit | e9f457f056c55aaa3ef15f4ad0fbbf6ef99c0520 (patch) | |
| tree | 7f467d8185829b37d33d0daf83276c836dfb851a /arch/csky | |
| parent | a6f4ea748aa803565ed37d1f5ed8dea422fd027b (diff) | |
csky: Fixup regs.sr broken in ptrace
commit af89ebaa64de726ca0a39bbb0bf0c81a1f43ad50 upstream.
gpr_get() return the entire pt_regs (include sr) to userspace, if we
don't restore the C bit in gpr_set, it may break the ALU result in
that context. So the C flag bit is part of gpr context, that's why
riscv totally remove the C bit in the ISA. That makes sr reg clear
from userspace to supervisor privilege.
Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: stable@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'arch/csky')
| -rw-r--r-- | arch/csky/kernel/ptrace.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/arch/csky/kernel/ptrace.c b/arch/csky/kernel/ptrace.c index 313623a19ecb..885194720fe0 100644 --- a/arch/csky/kernel/ptrace.c +++ b/arch/csky/kernel/ptrace.c @@ -96,7 +96,8 @@ static int gpr_set(struct task_struct *target, if (ret) return ret; - regs.sr = task_pt_regs(target)->sr; + /* BIT(0) of regs.sr is Condition Code/Carry bit */ + regs.sr = (regs.sr & BIT(0)) | (task_pt_regs(target)->sr & ~BIT(0)); #ifdef CONFIG_CPU_HAS_HILO regs.dcsr = task_pt_regs(target)->dcsr; #endif |