From: "zhaoyang.huang" <zhaoyang.huang@unisoc.com>
To: Catalin Marinas <catalin.marinas@arm.com>,
Will Deacon <will@kernel.org>, Ard Biesheuvel <ardb@kernel.org>,
<linux-arm-kernel@lists.infradead.org>,
<linux-kernel@vger.kernel.org>,
Zhaoyang Huang <huangzhaoyang@gmail.com>, <steve.kang@unisoc.com>
Subject: [PATCH] arch: arm64: fix KERNEL_SEGMENT_COUNT error
Date: Wed, 29 Apr 2026 14:17:52 +0800 [thread overview]
Message-ID: <20260429061752.2880923-1-zhaoyang.huang@unisoc.com> (raw)
From: Zhaoyang Huang <zhaoyang.huang@unisoc.com>
During debug of a kernel panic, we find that the pte_t of the final
part of [data, end] segment got overflow to the next page of
init_pg_end[1] which is the gap page before early_init_stack[2].
This should be introduced by the KERNEL_SEGMENT_COUNT's value is 5
which should be 6 as map_segment are called 6 times for the segments
of (text, stext, rodata, inittext, initdata, data+bss)
[1]
crash_arm64_v9.0.1> vtop ffffffed00601000
VIRTUAL PHYSICAL
ffffffed00601000 83401000
PAGE DIRECTORY: ffffffecffd62000
PGD: ffffffecffd62da0 => 10000000833fb003
PMD: ffffff80033fb018 => 10000000833fe003
PTE: ffffff80033fe008 => 68000083401f03
PAGE: 83401000
PTE PHYSICAL FLAGS
68000083401f03 83401000 (VALID|SHARED|AF|NG|PXN|UXN)
PAGE PHYSICAL MAPPING INDEX CNT FLAGS
fffffffec00d0040 83401000 0 0 1 4000 reserved
[2]
ffffffed002c8000 (r) __pi__data
ffffffed0054e000 (d) __pi___bss_start
ffffffed005f5000 (b) __pi_init_pg_dir
ffffffed005fe000 (b) __pi_init_pg_end
ffffffed005ff000 (B) early_init_stack
ffffffed00608000 (b) __pi__end
Signed-off-by: Zhaoyang Huang <zhaoyang.huang@unisoc.com>
---
arch/arm64/include/asm/kernel-pgtable.h | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/arch/arm64/include/asm/kernel-pgtable.h b/arch/arm64/include/asm/kernel-pgtable.h
index 74a4f738c5f5..14dd1c52552a 100644
--- a/arch/arm64/include/asm/kernel-pgtable.h
+++ b/arch/arm64/include/asm/kernel-pgtable.h
@@ -64,8 +64,8 @@
#define INIT_IDMAP_FDT_PAGES (EARLY_PAGES(INIT_IDMAP_PGTABLE_LEVELS, 0UL, UL(MAX_FDT_SIZE), 1) - 1)
#define INIT_IDMAP_FDT_SIZE ((INIT_IDMAP_FDT_PAGES + EARLY_IDMAP_EXTRA_FDT_PAGES) * PAGE_SIZE)
-/* The number of segments in the kernel image (text, rodata, inittext, initdata, data+bss) */
-#define KERNEL_SEGMENT_COUNT 5
+/* The number of segments in the kernel image (text, stext, rodata, inittext, initdata, data+bss) */
+#define KERNEL_SEGMENT_COUNT 6
#if SWAPPER_BLOCK_SIZE > SEGMENT_ALIGN
#define EARLY_SEGMENT_EXTRA_PAGES (KERNEL_SEGMENT_COUNT + 1)
--
2.25.1
next reply other threads:[~2026-04-29 6:20 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-04-29 6:17 zhaoyang.huang [this message]
2026-04-29 8:03 ` [PATCH] arch: arm64: fix KERNEL_SEGMENT_COUNT error Zhaoyang Huang
2026-04-29 9:27 ` Ard Biesheuvel
2026-04-30 1:29 ` Zhaoyang Huang
2026-04-30 1:56 ` Zhaoyang Huang
2026-04-30 7:59 ` Ard Biesheuvel
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