linux-kernel - [PATCH v1 1/1] x86/platform/quark: Print boundaries correctly

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Message-Id: <1453317596-25356-1-git-send-email-andriy.shevchenko@linux.intel.com>
Date:	Wed, 20 Jan 2016 21:19:56 +0200
From:	Andy Shevchenko <andriy.shevchenko@...ux.intel.com>
To:	Thomas Gleixner <tglx@...utronix.de>,
	Ingo Molnar <mingo@...hat.com>,
	"H. Peter Anvin" <hpa@...or.com>, linux-kernel@...r.kernel.org,
	"Ong, Boon Leong" <boon.leong.ong@...el.com>
Cc:	Andy Shevchenko <andriy.shevchenko@...ux.intel.com>
Subject: [PATCH v1 1/1] x86/platform/quark: Print boundaries correctly

When we print values, such as @size, we have to understand that it's derived
from [begin .. end] as:

	size = end - begin + 1

On the opposite the @end is derived from the rest as:

	end = begin + size - 1

Correct the IMR code to print values correctly.

Note that @__end_rodata actually points to the next address after the aligned
.rodata section.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@...ux.intel.com>
---
 arch/x86/platform/intel-quark/imr.c | 10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/arch/x86/platform/intel-quark/imr.c b/arch/x86/platform/intel-quark/imr.c
index 0ee619f..47fd18f 100644
--- a/arch/x86/platform/intel-quark/imr.c
+++ b/arch/x86/platform/intel-quark/imr.c
@@ -228,11 +228,12 @@ static int imr_dbgfs_state_show(struct seq_file *s, void *unused)
 		if (imr_is_enabled(&imr)) {
 			base = imr_to_phys(imr.addr_lo);
 			end = imr_to_phys(imr.addr_hi) + IMR_MASK;
+			size = end - base + 1;
 		} else {
 			base = 0;
 			end = 0;
+			size = 0;
 		}
-		size = end - base;
 		seq_printf(s, "imr%02i: base=%pa, end=%pa, size=0x%08zx "
 			   "rmask=0x%08x, wmask=0x%08x, %s, %s\n", i,
 			   &base, &end, size, imr.rmask, imr.wmask,
@@ -598,14 +599,17 @@ static void __init imr_fixup_memmap(struct imr_device *idev)
 	 * Setup a locked IMR around the physical extent of the kernel
 	 * from the beginning of the .text secton to the end of the
 	 * .rodata section as one physically contiguous block.
+	 *
+	 * We don't round up @size since it is already PAGE_SIZE aligned.
+	 * See vmlinux.lds.S for details.
 	 */
 	ret = imr_add_range(base, size, IMR_CPU, IMR_CPU, true);
 	if (ret < 0) {
 		pr_err("unable to setup IMR for kernel: (%p - %p)\n",
-			&_text, &__end_rodata);
+			&_text, &__end_rodata - 1);
 	} else {
 		pr_info("protecting kernel .text - .rodata: %zu KiB (%p - %p)\n",
-			size / 1024, &_text, &__end_rodata);
+			size / 1024, &_text, &__end_rodata - 1);
 	}
 
 }
-- 
2.7.0.rc3