[components][lwp] fix signal ordering and ELF segment protection by BernardXiong · Pull Request #11895 · RT-Thread/rt-thread

BernardXiong · 2026-10-18T11:36:06Z

拉取/合并请求描述：(PR description)

为什么提交这份PR (why to submit this PR)

Signals with the same number were inserted in reverse order, ELF segments were always mapped read-write regardless of p_flags, and RISC-V signal handling ran with interrupts disabled while taking sleeping locks.

你的解决方案是什么 (what is your solution)

keep FIFO order for signals carrying the same signal number
map ELF segments with permissions derived from p_flags
keep the scheduler usable while handling signals on RISC-V

请提供验证的bsp和config (provide the config and bsp)

BSP: bsp/qemu-virt64-riscv (RT-Thread Smart)
.config: CONFIG_RT_USING_SMART=y
action: local build not run; the RISC-V musleabi toolchain is not available in this environment, CI will verify the build

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我在这个拉取/合并请求中已经考虑了 As part of this pull request, I've considered the following:

已经仔细查看过代码改动的对比 Already check the difference between PR and old code
代码风格正确，包括缩进空格，命名及其他风格 Style guide is adhered to, including spacing, naming and other styles
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所有变更均有原因及合理的，并且不会影响到其他软件组件代码或BSP All modifications are justified and not affect other components or BSP
对难懂代码均提供对应的注释 I've commented appropriately where code is tricky
代码是高质量的 Code in this PR is of high quality
已经使用clang-format 源码格式化工具确保格式符合RT-Thread代码规范 This PR has been formatted with clang-format and complies with RT-Thread code specification
如果是新增bsp, 已经添加ci检查到.github/ALL_BSP_COMPILE.json 详细请参考链接BSP自查

- keep FIFO order for signals carrying the same signal number - map ELF segments with permissions derived from p_flags - keep the scheduler usable while handling signals on RISC-V

github-actions · 2026-10-18T12:42:22Z

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github-actions · 2026-10-18T12:42:41Z

📌 Code Review Assignment

🏷️ Tag: components

Reviewers: @Maihuanyi

Changed Files (Click to expand)

components/lwp/arch/risc-v/rv64/lwp_gcc.S
components/lwp/lwp_elf.c
components/lwp/lwp_signal.c

🏷️ Tag: components_lwp

Reviewers: @xu18838022837

Changed Files (Click to expand)

components/lwp/arch/risc-v/rv64/lwp_gcc.S
components/lwp/lwp_elf.c
components/lwp/lwp_signal.c

📊 Current Review Status (Last Updated: 2026-11-01 00:52 CST)

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⌛ @xu18838022837 Pending Review

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- expand the protection flag checks to braced statements - no functional change

github-actions · 2026-10-18T16:12:50Z

MemBrowse Memory Report · Explore what changed →

esp32-c3

dram0_0_seg: .dram0.bss +9,208 B, .dram0.data +168 B, .dram0.dummy -22,016 B (-5.7%, 208,608 B / 325,120 B, total: 64% used)
drom0_0_seg: .eh_frame +78,544 B, .eh_frame_hdr +12,376 B, .flash.rodata +27,368 B, .flash_rodata_dummy +196,608 B (+76.6%, 725,908 B / 8,388,576 B, total: 9% used)
iram0_0_seg: .iram0.text -21,766 B, .iram0.text_end -250 B (-29.3%, 53,248 B / 325,120 B, total: 16% used)
iram0_2_seg: .flash.text +199,784 B, .text +474 B (+87.2%, 429,852 B / 8,388,576 B, total: 5% used)
rtc_iram_seg: .rtc.text +8 B (+60.0%, 64 B / 8,192 B, total: 1% used)

k230

SRAM: .bss +4,096 B, .data +8 B, .eh_frame +13,752 B, .sbss +120 B, .srodata.cst8 +16 B, .stack -8 B, .text +62,648 B (+7.1%, 1,209,180 B / 268,300,288 B, total: 0% used)

nordic-nrf51822

FLASH: .text -8 B (-0.0%, 52,028 B / 262,144 B, total: 20% used)

nuvoton-m487

CODE: .text +24 B (+0.0%, 356,200 B / 524,288 B, total: 68% used)

qemu-virt64-aarch64

Code: .eh_frame -15,064 B, .text -52,624 B (-6.3%, 1,010,124 B)
Data: .bss +597,200 B, .data -47,560 B (+106.2%, 1,067,160 B)

raspberry-pico-rp2040

FLASH: .text -8 B (-0.0%, 114,160 B / 2,097,152 B, total: 5% used)

simulator

Code: .eh_frame +4 B, .rela.dyn -216 B, .rodata -23 B, .text +5 B (-0.0%, 2,672,790 B)
Data: .data -256 B (-0.0%, 1,609,028 B)

No memory changes detected for:

_{Catch memory regressions in CI with MemBrowse. Free for open source.}

rcitach · 2026-10-28T09:16:35Z

+static size_t elf_prot_from_pflags(uint32_t p_flags)
+{
+    size_t prot = PROT_NONE;
+    if (p_flags & PF_R)
+    {
+        prot |= PROT_READ;
+    }
+    if (p_flags & PF_W)
+    {
+        prot |= PROT_WRITE;
+    }
+    if (p_flags & PF_X)
+    {
+        prot |= PROT_EXEC;
+    }
+    return prot;
+}
+


这个在后续的：

rt-thread/components/lwp/lwp_user_mm.h

Lines 213 to 232 in ff82e23

rt_inline rt_size_t lwp_user_mm_attr_to_kernel(int prot)

{

RT_UNUSED(prot);

rt_size_t k_attr = 0;

#ifdef LWP_USING_MPROTECT

if ((prot & PROT_EXEC) || (prot & PROT_WRITE) ||

((prot & PROT_READ) && (prot & PROT_WRITE)))

k_attr = MMU_MAP_U_RWCB;

else if (prot == PROT_NONE)

k_attr = MMU_MAP_K_RWCB;

else

k_attr = MMU_MAP_U_ROCB;

#else /* !LWP_USING_MPROTECT */

k_attr = MMU_MAP_U_RWCB;

#endif /* LWP_USING_MPROTECT */

return k_attr;

}

不开启 LWP_USING_MPROTECT 会默认设置为 MMU_MAP_U_RWCB，此处是否需要添加 LWP_USING_MPROTECT 控制比较好一些

并且原本 elf_file_mmap 的注释放到了elf_prot_from_pflags 前面了

这里的 prot 只有在开启 LWP_USING_MPROTECT 时才真正生效：lwp_user_mm_attr_to_kernel() 在未开启 MPROTECT 时（lwp_user_mm.h 的 #else 分支）会忽略入参并统一返回 MMU_MAP_U_RWCB，所以映射行为和修改前完全一致，这里不需要再额外加 #ifdef 控制。

已在 commit 7fae086 的调用点补充注释说明这一点，避免后续读者误以为未开启 MPROTECT 时会被映射成只读/可执行。

已修正（commit 7fae086）：把 elf_prot_from_pflags() 移到 elf_file_mmap() 的 kernel-doc 注释之前，并给这个 helper 单独补了简短注释，elf_file_mmap() 的文档重新紧挨着函数。

Move the new elf_prot_from_pflags() helper above the kernel-doc block of elf_file_mmap() so the documentation stays attached to the function it describes. Also document that deriving the protection from p_flags is a no-op while LWP_USING_MPROTECT is disabled, because lwp_user_mm_attr_to_kernel() maps every attribute as MMU_MAP_U_RWCB. Co-Authored-By: Claude Code <noreply@anthropic.com>

[components][lwp] fix signal ordering and ELF segment protection

c250045

- keep FIFO order for signals carrying the same signal number - map ELF segments with permissions derived from p_flags - keep the scheduler usable while handling signals on RISC-V

BernardXiong marked this pull request as ready for review October 18, 2026 12:07

github-actions Bot added RT-Smart RT-Thread Smart related PR or issues component: lwp Component labels Oct 18, 2026

[components][lwp] apply clang-format to ELF protection helper

5fc0bd6

- expand the protection flag checks to braced statements - no functional change

rcitach reviewed Oct 28, 2026

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[components][lwp] fix signal ordering and ELF segment protection - #11895

[components][lwp] fix signal ordering and ELF segment protection#11895
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BernardXiong:pr/lwp-signal-elf

BernardXiong commented Oct 18, 2026 •

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	rt_inline rt_size_t lwp_user_mm_attr_to_kernel(int prot)
	{
	RT_UNUSED(prot);

	rt_size_t k_attr = 0;

	#ifdef LWP_USING_MPROTECT
	if ((prot & PROT_EXEC) \|\| (prot & PROT_WRITE) \|\|
	((prot & PROT_READ) && (prot & PROT_WRITE)))
	k_attr = MMU_MAP_U_RWCB;
	else if (prot == PROT_NONE)
	k_attr = MMU_MAP_K_RWCB;
	else
	k_attr = MMU_MAP_U_ROCB;
	#else /* !LWP_USING_MPROTECT */
	k_attr = MMU_MAP_U_RWCB;
	#endif /* LWP_USING_MPROTECT */

	return k_attr;
	}

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拉取/合并请求描述：(PR description)

为什么提交这份PR (why to submit this PR)

你的解决方案是什么 (what is your solution)

请提供验证的bsp和config (provide the config and bsp)

当前拉取/合并请求的状态 Intent for your PR

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📌 Code Review Assignment

🏷️ Tag: components

🏷️ Tag: components_lwp

📊 Current Review Status (Last Updated: 2026-11-01 00:52 CST)

📝 Review Instructions

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