cbe4ceb158
sys_callN() wraps a bare ecall and calls no other function, so the compiler treats it as a leaf function: with frame pointers enabled, it only needs to spill the caller's s0, which it places in what up_backtrace()'s fp-chain walk assumes is ra's stack slot, while the real ra slot is never written. sched_backtrace() then misreads that slot as the return address for this frame, either resolving to a bogus symbol or, if the adjacent garbage happens to look out-of-range, terminating the backtrace early. Add "ra" to the ecall clobber list so the compiler spills/reloads ra around the ecall like a normal call site, keeping ra and the saved s0 in their expected slots. Gate this on CONFIG_FRAME_POINTER && CONFIG_SCHED_BACKTRACE, the only combination where up_backtrace()'s fp-chain walk is both valid (FRAME_POINTER) and actually exercised (SCHED_BACKTRACE); other configurations keep the original "memory"-only clobber and pay no extra cost. This only fixes the syscall boundary. Leaf functions that do not cross a syscall (e.g. up_idle()) can still lose their ra slot the same way and are not addressed here. 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.