[PATCH v9 08/13] arm64: traps: Shuffle code to eliminate forward declarations

From: Mark Brown
Date: Wed Mar 11 2020 - 15:33:38 EST


From: Dave Martin <Dave.Martin@xxxxxxx>

Hoist the IT state handling code earlier in traps.c, to avoid
accumulating forward declarations.

No functional change.

Signed-off-by: Dave Martin <Dave.Martin@xxxxxxx>
Reviewed-by: Kees Cook <keescook@xxxxxxxxxxxx>
Signed-off-by: Mark Brown <broonie@xxxxxxxxxx>
---
arch/arm64/kernel/traps.c | 103 ++++++++++++++++++--------------------
1 file changed, 50 insertions(+), 53 deletions(-)

diff --git a/arch/arm64/kernel/traps.c b/arch/arm64/kernel/traps.c
index bc9f4292bfc3..3c07a7074145 100644
--- a/arch/arm64/kernel/traps.c
+++ b/arch/arm64/kernel/traps.c
@@ -272,7 +272,55 @@ void arm64_notify_die(const char *str, struct pt_regs *regs,
}
}

-static void advance_itstate(struct pt_regs *regs);
+#ifdef CONFIG_COMPAT
+#define PSTATE_IT_1_0_SHIFT 25
+#define PSTATE_IT_1_0_MASK (0x3 << PSTATE_IT_1_0_SHIFT)
+#define PSTATE_IT_7_2_SHIFT 10
+#define PSTATE_IT_7_2_MASK (0x3f << PSTATE_IT_7_2_SHIFT)
+
+static u32 compat_get_it_state(struct pt_regs *regs)
+{
+ u32 it, pstate = regs->pstate;
+
+ it = (pstate & PSTATE_IT_1_0_MASK) >> PSTATE_IT_1_0_SHIFT;
+ it |= ((pstate & PSTATE_IT_7_2_MASK) >> PSTATE_IT_7_2_SHIFT) << 2;
+
+ return it;
+}
+
+static void compat_set_it_state(struct pt_regs *regs, u32 it)
+{
+ u32 pstate_it;
+
+ pstate_it = (it << PSTATE_IT_1_0_SHIFT) & PSTATE_IT_1_0_MASK;
+ pstate_it |= ((it >> 2) << PSTATE_IT_7_2_SHIFT) & PSTATE_IT_7_2_MASK;
+
+ regs->pstate &= ~PSR_AA32_IT_MASK;
+ regs->pstate |= pstate_it;
+}
+
+static void advance_itstate(struct pt_regs *regs)
+{
+ u32 it;
+
+ /* ARM mode */
+ if (!(regs->pstate & PSR_AA32_T_BIT) ||
+ !(regs->pstate & PSR_AA32_IT_MASK))
+ return;
+
+ it = compat_get_it_state(regs);
+
+ /*
+ * If this is the last instruction of the block, wipe the IT
+ * state. Otherwise advance it.
+ */
+ if (!(it & 7))
+ it = 0;
+ else
+ it = (it & 0xe0) | ((it << 1) & 0x1f);
+
+ compat_set_it_state(regs, it);
+}

void arm64_skip_faulting_instruction(struct pt_regs *regs, unsigned long size)
{
@@ -285,7 +333,7 @@ void arm64_skip_faulting_instruction(struct pt_regs *regs, unsigned long size)
if (user_mode(regs))
user_fastforward_single_step(current);

- if (regs->pstate & PSR_MODE32_BIT)
+ if (compat_user_mode(regs))
advance_itstate(regs);
}

@@ -578,34 +626,6 @@ static const struct sys64_hook sys64_hooks[] = {
{},
};

-
-#ifdef CONFIG_COMPAT
-#define PSTATE_IT_1_0_SHIFT 25
-#define PSTATE_IT_1_0_MASK (0x3 << PSTATE_IT_1_0_SHIFT)
-#define PSTATE_IT_7_2_SHIFT 10
-#define PSTATE_IT_7_2_MASK (0x3f << PSTATE_IT_7_2_SHIFT)
-
-static u32 compat_get_it_state(struct pt_regs *regs)
-{
- u32 it, pstate = regs->pstate;
-
- it = (pstate & PSTATE_IT_1_0_MASK) >> PSTATE_IT_1_0_SHIFT;
- it |= ((pstate & PSTATE_IT_7_2_MASK) >> PSTATE_IT_7_2_SHIFT) << 2;
-
- return it;
-}
-
-static void compat_set_it_state(struct pt_regs *regs, u32 it)
-{
- u32 pstate_it;
-
- pstate_it = (it << PSTATE_IT_1_0_SHIFT) & PSTATE_IT_1_0_MASK;
- pstate_it |= ((it >> 2) << PSTATE_IT_7_2_SHIFT) & PSTATE_IT_7_2_MASK;
-
- regs->pstate &= ~PSR_AA32_IT_MASK;
- regs->pstate |= pstate_it;
-}
-
static bool cp15_cond_valid(unsigned int esr, struct pt_regs *regs)
{
int cond;
@@ -626,29 +646,6 @@ static bool cp15_cond_valid(unsigned int esr, struct pt_regs *regs)
return aarch32_opcode_cond_checks[cond](regs->pstate);
}

-static void advance_itstate(struct pt_regs *regs)
-{
- u32 it;
-
- /* ARM mode */
- if (!(regs->pstate & PSR_AA32_T_BIT) ||
- !(regs->pstate & PSR_AA32_IT_MASK))
- return;
-
- it = compat_get_it_state(regs);
-
- /*
- * If this is the last instruction of the block, wipe the IT
- * state. Otherwise advance it.
- */
- if (!(it & 7))
- it = 0;
- else
- it = (it & 0xe0) | ((it << 1) & 0x1f);
-
- compat_set_it_state(regs, it);
-}
-
static void compat_cntfrq_read_handler(unsigned int esr, struct pt_regs *regs)
{
int reg = (esr & ESR_ELx_CP15_32_ISS_RT_MASK) >> ESR_ELx_CP15_32_ISS_RT_SHIFT;
--
2.20.1