[PATCH v2 2/3] xen/arm: Extend the memory overlap check to include bootmodules

[Henry Wang <Henry.Wang@xxxxxxx>]

Similarly as the static regions defined in bootinfo.reserved_mem,
the bootmodule regions defined in bootinfo.modules should also not
be overlapping with memory regions in either bootinfo.reserved_mem
or bootinfo.modules.

Therefore, this commit introduces a helper `bootmodules_overlap_check()`
and uses this helper to extend the check in function
`check_reserved_regions_overlap()` so that memory regions in
bootinfo.modules are included. Use `check_reserved_regions_overlap()`
in `add_boot_module()` to return early if any error occurs.

Signed-off-by: Henry Wang <Henry.Wang@xxxxxxx>
---
v1 -> v2:
1. Split original `overlap_check()` to `bootmodules_overlap_check()`.
2. Rework commit message.
---
 xen/arch/arm/setup.c | 34 ++++++++++++++++++++++++++++++++++
 1 file changed, 34 insertions(+)

diff --git a/xen/arch/arm/setup.c b/xen/arch/arm/setup.c
index e6eeb3a306..ba0152f868 100644
--- a/xen/arch/arm/setup.c
+++ b/xen/arch/arm/setup.c
@@ -286,6 +286,31 @@ static int __init meminfo_overlap_check(struct meminfo 
*meminfo,
     return 0;
 }
 
+static int __init bootmodules_overlap_check(struct bootmodules *bootmodules,
+                                            paddr_t region_start,
+                                            paddr_t region_end)
+{
+    paddr_t mod_start = INVALID_PADDR, mod_end = 0;
+    unsigned int i, mod_num = bootmodules->nr_mods;
+
+    for ( i = 0; i < mod_num; i++ )
+    {
+        mod_start = bootmodules->module[i].start;
+        mod_end = mod_start + bootmodules->module[i].size;
+
+        if ( region_end <= mod_start || region_start >= mod_end )
+            continue;
+        else
+        {
+            printk("Region %#"PRIpaddr" - %#"PRIpaddr" overlapping with 
mod[%u] %#"PRIpaddr" - %#"PRIpaddr"\n",
+                   region_start, region_end, i, mod_start, mod_end);
+            return -EINVAL;
+        }
+    }
+
+    return 0;
+}
+
 void __init fw_unreserved_regions(paddr_t s, paddr_t e,
                                   void (*cb)(paddr_t, paddr_t),
                                   unsigned int first)
@@ -312,6 +337,11 @@ int __init check_reserved_regions_overlap(paddr_t 
region_start,
                                region_start, region_end) )
         return -EINVAL;
 
+    /* Check if input region is overlapping with bootmodules */
+    if ( bootmodules_overlap_check(&bootinfo.modules,
+                                   region_start, region_end) )
+        return -EINVAL;
+
     return 0;
 }
 
@@ -329,6 +359,10 @@ struct bootmodule __init *add_boot_module(bootmodule_kind 
kind,
                boot_module_kind_as_string(kind), start, start + size);
         return NULL;
     }
+
+    if ( check_reserved_regions_overlap(start, size) )
+        return NULL;
+
     for ( i = 0 ; i < mods->nr_mods ; i++ )
     {
         mod = &mods->module[i];
-- 
2.25.1