From:   Jungseung Lee <js07.lee@samsung.com>
To:     rmk+kernel@armlinux.org.uk, linus.walleij@linaro.org,
        amit.kachhap@arm.com, ardb@kernel.org,
        linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org,
        keescook@chromium.org, js07.lee@samsung.com, js07.lee@gmail.com
Subject: [PATCH 1/2] arm/mm : omit [_text, _stext) from kernel code region
Date:   Mon,  6 Mar 2023 14:51:54 +0900
Message-Id: <1678081915-12599-1-git-send-email-js07.lee@samsung.com>
Content-Type: text/plain; charset="utf-8"
CMS-TYPE: 101P
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References: <CGME20230306061055epcas1p1f7718c46c10f84845e086f9ce9f9a41f@epcas1p1.samsung.com>
Precedence: bulk

The resource reservations in /proc/iomem made for the kernel code did
not reflect the gaps between pagetable and text.

In particular, if the CONFIG_STRICT_KERNEL_RWX option is turned on,
the wrong area is shown as the kernel code area.

Fix it by removing [_text, _stext) from kernel code region.

Before:
04000000-2f7fffff : System RAM
  04008000-04cfffff : Kernel code
  04e00000-05369a27 : Kernel data

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

Signed-off-by: Jungseung Lee <js07.lee@samsung.com>
---
 arch/arm/kernel/setup.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/arm/kernel/setup.c b/arch/arm/kernel/setup.c
index 75cd469..3059860 100644
--- a/arch/arm/kernel/setup.c
+++ b/arch/arm/kernel/setup.c
@@ -865,7 +865,7 @@ static void __init request_standard_resources(const struct machine_desc *mdesc)
 	struct resource *res;
 	u64 i;
 
-	kernel_code.start   = virt_to_phys(_text);
+	kernel_code.start   = virt_to_phys(_stext);
 	kernel_code.end     = virt_to_phys(__init_begin - 1);
 	kernel_data.start   = virt_to_phys(_sdata);
 	kernel_data.end     = virt_to_phys(_end - 1);
@@ -1139,7 +1139,7 @@ void __init setup_arch(char **cmdline_p)
 	if (mdesc->reboot_mode != REBOOT_HARD)
 		reboot_mode = mdesc->reboot_mode;
 
-	setup_initial_init_mm(_text, _etext, _edata, _end);
+	setup_initial_init_mm(_stext, _etext, _edata, _end);
 
 	/* populate cmd_line too for later use, preserving boot_command_line */
 	strlcpy(cmd_line, boot_command_line, COMMAND_LINE_SIZE);
-- 
2.7.4