leisiji opened a new pull request, #19175:
URL: https://github.com/apache/nuttx/pull/19175
* Fix a bug in `arm_addrenv_create_region()` where L1 page table entries
for second and subsequent 1MB sections were offset by `i * SECTION_SIZE`,
causing virtual address holes in the mapping.
* The inner loop already advances `vaddr` by `MM_PGSIZE` for each mapped
page, so after filling one L2 page table (i.e. `ENTRIES_PER_L2TABLE`
pages), `vaddr` has naturally advanced to the start of the next 1MB
section.
* The redundant `vaddr + i * SECTION_SIZE` in `mmu_l1table_setentry()`
caused each L1 entry after the first to skip one section per iteration,
leaving unmapped gaps between sections.
* Related NuttX Issue: N/A
## Impact
* Is new feature added? Is existing feature changed? NO — bug fix only.
* Impact on user (will user need to adapt to change)? NO.
* Impact on build (will build process change)? NO.
* Impact on hardware (will arch(s) / board(s) / driver(s) change)?
YES — affects all ARMv7-A targets that use `arm_addrenv_create_region()`
for address environment creation. Fixes incorrect virtual address
mappings.
* Impact on documentation (is update required / provided)? NO.
* Impact on security (any sort of implications)? NO.
* Impact on compatibility (backward/forward/interoperability)? NO.
* Anything else to consider or add? None.
## Testing
I confirm that changes are verified on local setup and works as intended:
* Build Host(s): Linux, x86_64, GCC
* Target(s): arm (ARMv7-A), qemu-armv7a:knsh
* The fix produces contiguous L1 section mappings instead of leaving
virtual address holes between sections.
Setup config:
```txt
diff --git a/boards/arm/qemu/qemu-armv7a/configs/knsh/defconfig
b/boards/arm/qemu/qemu-armv7a/configs/knsh/defconfig
index 18b086834c..6cfe59b4da 100644
--- a/boards/arm/qemu/qemu-armv7a/configs/knsh/defconfig
+++ b/boards/arm/qemu/qemu-armv7a/configs/knsh/defconfig
@@ -14,10 +14,10 @@ CONFIG_ARCH_BOARD_QEMU_ARMV7A=y
CONFIG_ARCH_CHIP="qemu"
CONFIG_ARCH_CHIP_QEMU_ARM=y
CONFIG_ARCH_CHIP_QEMU_CORTEXA7=y
-CONFIG_ARCH_DATA_NPAGES=256
-CONFIG_ARCH_DATA_VBASE=0x80100000
-CONFIG_ARCH_HEAP_NPAGES=256
-CONFIG_ARCH_HEAP_VBASE=0x80200000
+CONFIG_ARCH_DATA_NPAGES=512
+CONFIG_ARCH_DATA_VBASE=0x80200000
+CONFIG_ARCH_HEAP_NPAGES=512
+CONFIG_ARCH_HEAP_VBASE=0x80400000
CONFIG_ARCH_INTERRUPTSTACK=2048
CONFIG_ARCH_KERNEL_STACKSIZE=3072
CONFIG_ARCH_LOWVECTORS=y
@@ -26,7 +26,7 @@ CONFIG_ARCH_PGPOOL_PBASE=0x40300000
CONFIG_ARCH_PGPOOL_SIZE=13631488
CONFIG_ARCH_PGPOOL_VBASE=0x40300000
CONFIG_ARCH_STACKDUMP=y
-CONFIG_ARCH_TEXT_NPAGES=256
+CONFIG_ARCH_TEXT_NPAGES=512
CONFIG_ARCH_TEXT_VBASE=0x80000000
CONFIG_ARM_PSCI=y
CONFIG_ARM_SEMIHOSTING_HOSTFS=y
```
Build and run:
```bash
cmake -B build -DBOARD_CONFIG=qemu-armv7a:knsh -GNinja && cmake --build build
qemu-system-arm -semihosting -M virt -m 128 -nographic -kernel ./build/nuttx
```
Logs before this change:
```
[ 0.007000] arm_dataabort: Data abort. PC: 0000361c DFAR: 805ffffc DFSR:
00000805
[ 0.007000] dump_assert_info: Current Version: NuttX 0.0.0
2be1345a7c-dirty Jun 19 2026 11:12:02 arm
[ 0.007000] dump_assert_info: Assertion failed panic: at file:
/arch/arm/src/armv7-a/arm_dataabort.c:174 task: AppBringUp process: Kernel
0x3b69
[ 0.007000] up_dump_register: R0: 00000009 R1: 80400170 R2: 0000000b R3:
80400178
[ 0.007000] up_dump_register: R4: 80400000 R5: 805ffff8 R6: 001ffe90 FP:
400066dc
[ 0.007000] up_dump_register: R8: 001ffe90 SB: 40006720 SL: 00000001 R11:
40006d50
[ 0.007000] up_dump_register: IP: 00000000 SP: 400066b0 LR: 00002491 PC:
0000361c
[ 0.007000] up_dump_register: CPSR: 2000007f
[ 0.007000] dump_stackinfo: User Stack:
[ 0.007000] dump_stackinfo: base: 0x40005910
[ 0.007000] dump_stackinfo: size: 00004048
[ 0.007000] dump_stackinfo: sp: 0x400066b0
[ 0.007000] stack_dump: 0x40006690: 400066dc 001ffe90 40006720 00000001
40006d50 00000000 0000361c 2000007f
[ 0.007000] stack_dump: 0x400066b0: 80400000 80400170 00000000 0000370f
80400000 40006ae8 40006a58 40006714
[ 0.007000] stack_dump: 0x400066d0: 40006710 00010165 80400000 00000000
00000000 80400000 00200000 00000001
[ 0.007000] stack_dump: 0x400066f0: 40006a58 000098bf 00000006 00002465
40004000 40004000 40006918 0000375d
[ 0.007000] stack_dump: 0x40006710: 40006be8 00000000 00000006 80400000
7379732f 2f6d6574 2f6e6962 74696e69
[ 0.007000] stack_dump: 0x40006730: 7fffff00 00003261 40000668 40006ae8
00000000 0000377d 40006ae8 00001edd
[ 0.007000] stack_dump: 0x40006750: 00000000 40006768 00000000 0000e36d
00000000 000096cb 80000000 80201000
[ 0.007000] stack_dump: 0x40006770: 000099b8 000007a4 00000008 00000004
0000b4ec 00000000 00000000 000081ff
[ 0.007000] stack_dump: 0x40006790: 464c457f 00010101 00000000 00000000
00280002 00000001 800000ed 00000034
[ 0.007000] stack_dump: 0x400067b0: 0000b334 05000400 00200034 00280002
000a000b 00000000 00000000 00000000
[ 0.007000] stack_dump: 0x400067d0: 00000000 00000000 00000000 00000000
00000000 00000000 00000000 00000000
[ 0.007000] stack_dump: 0x400067f0: 00000000 00000000 ffffffff 00000000
fffffffe 00000000 40006d50 00000000
[ 0.007000] stack_dump: 0x40006810: 00000000 40000178 40006a58 00017343
00009671 00000000 40006a58 00017343
[ 0.007000] stack_dump: 0x40006830: 400068a8 400068a4 00000000 00000000
00000000 000095d7 00000000 400068a8
[ 0.007000] stack_dump: 0x40006850: 00000001 40006a20 40006918 00000000
400068a8 00000c00 00000064 00000000
[ 0.007000] stack_dump: 0x40006870: 00000000 0000960b 00000000 00000000
400068a8 00000001 00000000 00003bc7
[ 0.007000] stack_dump: 0x40006890: 00000000 00000000 400068a8 400068e0
00000000 00000000 00026400 00000000
[ 0.007000] stack_dump: 0x400068b0: 00000000 00000c00 00000000 400057e0
00000002 00000000 00000000 000054c3
[ 0.007000] stack_dump: 0x400068d0: 00000000 00000000 00000000 00000000
00000000 00000000 00000000 00000000
[ 0.007000] dump_tasks: PID GROUP PRI POLICY TYPE NPX STATE
EVENT SIGMASK STACKBASE STACKSIZE USED FILLED COMMAND
[ 0.007000] dump_tasks: ---- --- --- -------- ------- --- -------
---------- ---------------- 0x40001ab8 2048 120 5.8% irq
[ 0.007000] dump_task: 0 0 0 FIFO Kthread - Ready
0000000000000000 0x40003018 4072 704 17.2% Idle_Task
[ 0.007000] dump_task: 1 0 100 RR Kthread - Ready
0000000000000000 0x40004820 4024 328 8.1% lpwork
0x400000d8 0x40000128
[ 0.007000] dump_task: 2 0 240 RR Kthread - Running
0000000000000000 0x40005910 4048 1704 42.0% AppBringUp
```
## PR verification Self-Check
* [x] This PR introduces only one functional change.
* [x] I have updated all required description fields above.
* [x] My PR adheres to Contributing Guidelines and Documentation (git
commitandard, etc).
* [ ] My PR is still work in progress (not ready for review).
* [x] My PR is ready for review and can be safely merged into a codebase.
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