lib: utils/irqchip: plic: Ensure no out-of-bound access in priority save/restore helpers

Currently the priority save/restore helpers writes/reads the provided
array using an index whose maximum value is determined by PLIC, which
potentially may disagree with the caller to these helpers.

Add a parameter to ask the caller to provide the size limit of the
array to ensure no out-of-bound access happens.

Signed-off-by: Bin Meng <[email protected]>
Reviewed-by: Anup Patel <[email protected]>

2 files changed, 9 insertions, 8 deletions

diff --git a/lib/utils/irqchip/fdt_irqchip_plic.c b/lib/utils/irqchip/fdt_irqchip_plic.c
index 8e90fa75..1c37512c 100644
--- a/lib/utils/irqchip/fdt_irqchip_plic.c
+++ b/lib/utils/irqchip/fdt_irqchip_plic.c
@@ -24,18 +24,18 @@ static struct plic_data plic[PLIC_MAX_NR];
 static struct plic_data *plic_hartid2data[SBI_HARTMASK_MAX_BITS];
 static int plic_hartid2context[SBI_HARTMASK_MAX_BITS][2];
 
-void fdt_plic_priority_save(u8 *priority)
+void fdt_plic_priority_save(u8 *priority, u32 num)
 {
 	struct plic_data *plic = plic_hartid2data[current_hartid()];
 
-	plic_priority_save(plic, priority);
+	plic_priority_save(plic, priority, num);
 }
 
-void fdt_plic_priority_restore(const u8 *priority)
+void fdt_plic_priority_restore(const u8 *priority, u32 num)
 {
 	struct plic_data *plic = plic_hartid2data[current_hartid()];
 
-	plic_priority_restore(plic, priority);
+	plic_priority_restore(plic, priority, num);
 }
 
 void fdt_plic_context_save(bool smode, u32 *enable, u32 *threshold)
diff --git a/lib/utils/irqchip/plic.c b/lib/utils/irqchip/plic.c
index 4df90208..c5c18796 100644
--- a/lib/utils/irqchip/plic.c
+++ b/lib/utils/irqchip/plic.c
@@ -36,15 +36,16 @@ static void plic_set_priority(const struct plic_data *plic, u32 source, u32 val)
 	writel(val, plic_priority);
 }
 
-void plic_priority_save(const struct plic_data *plic, u8 *priority)
+void plic_priority_save(const struct plic_data *plic, u8 *priority, u32 num)
 {
-	for (u32 i = 1; i <= plic->num_src; i++)
+	for (u32 i = 1; i <= num; i++)
 		priority[i] = plic_get_priority(plic, i);
 }
 
-void plic_priority_restore(const struct plic_data *plic, const u8 *priority)
+void plic_priority_restore(const struct plic_data *plic, const u8 *priority,
+			   u32 num)
 {
-	for (u32 i = 1; i <= plic->num_src; i++)
+	for (u32 i = 1; i <= num; i++)
 		plic_set_priority(plic, i, priority[i]);
 }