6bfb85c96f
riscv_fillpage() is the LOADPF/STOREPF handler used under CONFIG_PAGING. It checked whether intermediate page table levels were already allocated, but never checked the final leaf PTE before installing a new mapping. RISC-V raises the same LOADPF/STOREPF cause both when a leaf PTE is absent (a real fault) and when it is present but its permission bits don't satisfy the access, e.g. a store to a .text page whose write access was revoked after ELF loading. The two cases are indistinguishable from mcause alone. Treating both cases as "page missing" let riscv_fillpage silently allocate a fresh, zeroed physical page over an existing mapping, discarding the old page (a leak) and defeating whatever permission that mapping was enforcing. Reproduced on real hardware: a user-space store to an already-loaded .text page got a fresh writable page instead of being rejected. Check the leaf PTE's valid bit before allocating; if a mapping already exists, panic instead of overwriting it. Signed-off-by: liang.huang <liang.huang@houmo.ai> |
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| .github | ||
| arch | ||
| audio | ||
| binfmt | ||
| boards | ||
| cmake | ||
| crypto | ||
| Documentation | ||
| drivers | ||
| dummy | ||
| fs | ||
| graphics | ||
| include | ||
| libs | ||
| mm | ||
| net | ||
| openamp | ||
| pass1 | ||
| sched | ||
| syscall | ||
| tools | ||
| video | ||
| wireless | ||
| .asf.yaml | ||
| .codespell-ignore-lines | ||
| .codespellrc | ||
| .editorconfig | ||
| .gitignore | ||
| .gitmessage | ||
| .pre-commit-config.yaml | ||
| .yamllint | ||
| AUTHORS | ||
| CMakeLists.txt | ||
| CONTRIBUTING.md | ||
| INVIOLABLES.md | ||
| Kconfig | ||
| LICENSE | ||
| Makefile | ||
| NOTICE | ||
| README.md | ||
| ReleaseNotes | ||
Apache NuttX is a real-time operating system (RTOS) with an emphasis on standards compliance and small footprint. Scalable from 8-bit to 64-bit microcontroller environments, the primary governing standards in NuttX are POSIX and ANSI standards. Additional standard APIs from Unix and other common RTOSs (such as VxWorks) are adopted for functionality not available under these standards, or for functionality that is not appropriate for deeply-embedded environments (such as fork()).
For brevity, many parts of the documentation will refer to Apache NuttX as simply NuttX.
Getting Started
First time on NuttX? Read the Getting Started guide! If you don't have a board available, NuttX has its own simulator that you can run on terminal.
Documentation
You can find the current NuttX documentation on the Documentation Page.
Alternatively, you can build the documentation yourself by following the Documentation Build Instructions.
The old NuttX documentation is still available in the Apache wiki.
Supported Boards
NuttX supports a wide variety of platforms. See the full list on the Supported Platforms page.
Contributing
If you wish to contribute to the NuttX project, read the Contributing guidelines for information on Git usage, coding standard, workflow and the NuttX principles.
License
The code in this repository is under either the Apache 2 license, or a license compatible with the Apache 2 license. See the License Page for more information.