[PATCH 2/2] arm/mm : Report actual image regions in /proc/iomem

From: Jungseung Lee
Date: Mon Mar 06 2023 - 01:11:14 EST


The resource reservations in /proc/iomem made for the kernel image did
not reflect the gaps between text, rodata, and data.
Add the "rodata" resource and update the start/end calculations.

Before :
04000000-2f7fffff : System RAM
04100000-04cfffff : Kernel code
04e00000-05369a27 : Kernel data

After :
04000000-2f7fffff : System RAM
04100000-049fffff : Kernel code
04a00000-04cb2fff : Kernel rodata
04e00000-05369a27 : Kernel data

Signed-off-by: Jungseung Lee <js07.lee@xxxxxxxxxxx>
---
arch/arm/kernel/setup.c | 20 ++++++++++++++++----
1 file changed, 16 insertions(+), 4 deletions(-)

diff --git a/arch/arm/kernel/setup.c b/arch/arm/kernel/setup.c
index 3059860..85af967 100644
--- a/arch/arm/kernel/setup.c
+++ b/arch/arm/kernel/setup.c
@@ -181,6 +181,12 @@ static struct resource mem_res[] = {
.flags = IORESOURCE_SYSTEM_RAM
},
{
+ .name = "Kernel rodata",
+ .start = 0,
+ .end = 0,
+ .flags = IORESOURCE_SYSTEM_RAM
+ },
+ {
.name = "Kernel data",
.start = 0,
.end = 0,
@@ -188,9 +194,10 @@ static struct resource mem_res[] = {
}
};

-#define video_ram mem_res[0]
-#define kernel_code mem_res[1]
-#define kernel_data mem_res[2]
+#define video_ram mem_res[0]
+#define kernel_code mem_res[1]
+#define kernel_rodata mem_res[2]
+#define kernel_data mem_res[3]

static struct resource io_res[] = {
{
@@ -866,7 +873,9 @@ static void __init request_standard_resources(const struct machine_desc *mdesc)
u64 i;

kernel_code.start = virt_to_phys(_stext);
- kernel_code.end = virt_to_phys(__init_begin - 1);
+ kernel_code.end = virt_to_phys(_etext - 1);
+ kernel_rodata.start = virt_to_phys(__start_rodata);
+ kernel_rodata.end = virt_to_phys(__end_rodata - 1);
kernel_data.start = virt_to_phys(_sdata);
kernel_data.end = virt_to_phys(_end - 1);

@@ -912,6 +921,9 @@ static void __init request_standard_resources(const struct machine_desc *mdesc)
if (kernel_code.start >= res->start &&
kernel_code.end <= res->end)
request_resource(res, &kernel_code);
+ if (kernel_rodata.start >= res->start &&
+ kernel_rodata.end <= res->end)
+ request_resource(res, &kernel_rodata);
if (kernel_data.start >= res->start &&
kernel_data.end <= res->end)
request_resource(res, &kernel_data);
--
2.7.4