[PATCH AUTOSEL 5.6 095/129] csky: Fixup get wrong psr value from phyical reg

Sasha Levin
2020-04-15T12:59:26Z

From: Guo Ren <guoren@linux.alibaba.com>

[ Upstream commit 9c0e343d7654a329d1f9b53d253cbf7fb6eff85d ]

We should get psr value from regs->psr in stack, not directly get
it from phyiscal register then save the vector number in
tsk->trap_no.

Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
arch/csky/include/asm/processor.h | 1 +
arch/csky/kernel/traps.c | 11 ++++++++++-
arch/csky/mm/fault.c | 7 +++++++
3 files changed, 18 insertions(+), 1 deletion(-)

diff --git a/arch/csky/include/asm/processor.h b/arch/csky/include/asm/processor.h
index 21e0bd5293dde..c6bcd7f7c720b 100644
--- a/arch/csky/include/asm/processor.h
+++ b/arch/csky/include/asm/processor.h
@@ -43,6 +43,7 @@ extern struct cpuinfo_csky cpu_data[];
struct thread_struct {
unsigned long ksp; /* kernel stack pointer */
unsigned long sr; /* saved status register */
+ unsigned long trap_no; /* saved status register */

/* FPU regs */
struct user_fp __aligned(16) user_fp;
diff --git a/arch/csky/kernel/traps.c b/arch/csky/kernel/traps.c
index b057480e7463c..63715cb90ee99 100644
--- a/arch/csky/kernel/traps.c
+++ b/arch/csky/kernel/traps.c
@@ -115,8 +115,9 @@ asmlinkage void trap_c(struct pt_regs *regs)
int sig;
unsigned long vector;
siginfo_t info;
+ struct task_struct *tsk = current;

- vector = (mfcr("psr") >> 16) & 0xff;
+ vector = (regs->sr >> 16) & 0xff;

switch (vector) {
case VEC_ZERODIV:
@@ -129,6 +130,7 @@ asmlinkage void trap_c(struct pt_regs *regs)
sig = SIGTRAP;
break;
case VEC_ILLEGAL:
+ tsk->thread.trap_no = vector;
die_if_kernel("Kernel mode ILLEGAL", regs, vector);
#ifndef CONFIG_CPU_NO_USER_BKPT
if (*(uint16_t *)instruction_pointer(regs) != USR_BKPT)
@@ -146,16 +148,20 @@ asmlinkage void trap_c(struct pt_regs *regs)
sig = SIGTRAP;
break;
case VEC_ACCESS:
+ tsk->thread.trap_no = vector;
return buserr(regs);
#ifdef CONFIG_CPU_NEED_SOFTALIGN
case VEC_ALIGN:
+ tsk->thread.trap_no = vector;
return csky_alignment(regs);
#endif
#ifdef CONFIG_CPU_HAS_FPU
case VEC_FPE:
+ tsk->thread.trap_no = vector;
die_if_kernel("Kernel mode FPE", regs, vector);
return fpu_fpe(regs);
case VEC_PRIV:
+ tsk->thread.trap_no = vector;
die_if_kernel("Kernel mode PRIV", regs, vector);
if (fpu_libc_helper(regs))
return;
@@ -164,5 +170,8 @@ asmlinkage void trap_c(struct pt_regs *regs)
sig = SIGSEGV;
break;
}
+
+ tsk->thread.trap_no = vector;
+
send_sig(sig, current, 0);
}
diff --git a/arch/csky/mm/fault.c b/arch/csky/mm/fault.c
index f76618b630f91..562c7f7087490 100644
--- a/arch/csky/mm/fault.c
+++ b/arch/csky/mm/fault.c
@@ -179,11 +179,14 @@ asmlinkage void do_page_fault(struct pt_regs *regs, unsigned long write,
bad_area_nosemaphore:
/* User mode accesses just cause a SIGSEGV */
if (user_mode(regs)) {
+ tsk->thread.trap_no = (regs->sr >> 16) & 0xff;
force_sig_fault(SIGSEGV, si_code, (void __user *)address);
return;
}

no_context:
+ tsk->thread.trap_no = (regs->sr >> 16) & 0xff;
+
/* Are we prepared to handle this kernel fault? */
if (fixup_exception(regs))
return;
@@ -198,6 +201,8 @@ asmlinkage void do_page_fault(struct pt_regs *regs, unsigned long write,
die_if_kernel("Oops", regs, write);

out_of_memory:
+ tsk->thread.trap_no = (regs->sr >> 16) & 0xff;
+
/*
* We ran out of memory, call the OOM killer, and return the userspace
* (which will retry the fault, or kill us if we got oom-killed).
@@ -206,6 +211,8 @@ asmlinkage void do_page_fault(struct pt_regs *regs, unsigned long write,
return;

do_sigbus:
+ tsk->thread.trap_no = (regs->sr >> 16) & 0xff;
+
up_read(&mm->mmap_sem);

/* Kernel mode? Handle exceptions or die */
--
2.20.1