Skip to content

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

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Open
BernardXiong wants to merge 2 commits into
base: master
Choose a base branch
from
Open

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

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
2 commits
Select commit Hold shift + click to select a range
c250045
[components][lwp] fix signal ordering and ELF segment protection
BernardXiong Oct 18, 2026
5fc0bd6
[components][lwp] apply clang-format to ELF protection helper
BernardXiong Oct 18, 2026
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
6 changes: 6 additions & 0 deletions components/lwp/arch/risc-v/rv64/lwp_gcc.S
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -109,6 +109,8 @@ arch_ret_to_user_impl:
// TODO: we don't support kernel gdb server in risc-v yet
// so we don't check debug state here and handle debugging bussiness

/* Signal handling takes sleeping locks and must remain schedulable. */
OPEN_INTERRUPT
call lwp_check_exit_request
beqz a0, 1f
mv a0, x0
Expand All @@ -121,6 +123,7 @@ arch_ret_to_user_impl:
call lwp_thread_signal_catch

ret_to_user_exit:
CLOSE_INTERRUPT
RESTORE_ALL
// `RESTORE_ALL` also reset sp to user sp, and setup sscratch
sret
Expand All @@ -130,8 +133,10 @@ ret_to_user_exit:
* And handle pending signals;
*/
arch_signal_quit:
OPEN_INTERRUPT
LOAD a0, FRAME_OFF_SP(sp)
call arch_signal_ucontext_restore
CLOSE_INTERRUPT

/* reset kernel sp to the stack */
addi sp, sp, CTX_REG_NR * REGBYTES
Expand Down Expand Up @@ -167,6 +172,7 @@ arch_thread_signal_enter:
LOAD t0, FRAME_OFF_SP(a2)
mv a3, t0
call arch_signal_ucontext_save
CLOSE_INTERRUPT

/** restore kernel sp */
addi sp, s3, CTX_REG_NR * REGBYTES
Expand Down
23 changes: 20 additions & 3 deletions components/lwp/lwp_elf.c
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -616,6 +616,24 @@ static int elf_zero_bss(struct rt_lwp *lwp, int fd, const Elf_Phdr *phdr, rt_uba
* @return -RT_ERROR if memory mapping fails.
* @return -ENOMEM if memory allocation fails.
*/
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;
}

Comment on lines +619 to +636

@rcitach rcitach Oct 28, 2026

Copy link
Copy Markdown
Contributor

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

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

@rcitach rcitach Oct 28, 2026

Copy link
Copy Markdown
Contributor

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

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

static int elf_file_mmap(elf_load_info_t *load_info, elf_info_t *elf_info, rt_ubase_t *elfload_addr,
rt_uint32_t map_size, rt_ubase_t *load_base)
{
Expand All @@ -626,7 +644,6 @@ static int elf_file_mmap(elf_load_info_t *load_info, elf_info_t *elf_info, rt_ub
const Elf_Phdr *tmp_phdr = phdr; /* Current program header */
int fd = elf_info->fd; /* File descriptor for ELF file */
rt_ubase_t load_addr; /* Calculated load address */
size_t prot = PROT_READ | PROT_WRITE; /* Memory protection flags */
size_t flags = MAP_FIXED | MAP_PRIVATE; /* Memory mapping flags */

/* Iterate through all program headers */
Expand Down Expand Up @@ -659,8 +676,8 @@ static int elf_file_mmap(elf_load_info_t *load_info, elf_info_t *elf_info, rt_ub
flags &= ~MAP_FIXED;
}

/* Map the segment into memory */
map_va = elf_map(load_info->lwp, tmp_phdr, fd, load_addr, prot, flags, map_size);
/* Map the segment into memory with correct permissions */
map_va = elf_map(load_info->lwp, tmp_phdr, fd, load_addr, elf_prot_from_pflags(tmp_phdr->p_flags), flags, map_size);
if (!map_va)
{
LOG_E("%s : elf_map failed", __func__);
Expand Down
5 changes: 3 additions & 2 deletions components/lwp/lwp_signal.c
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -255,9 +255,10 @@ static void sigqueue_enqueue(lwp_sigqueue_t sigqueue, lwp_siginfo_t siginfo)
rt_bool_t inserted = RT_FALSE;
rt_list_for_each_entry(idx, &sigqueue->siginfo_list, node)
{
if (idx->ksiginfo.signo >= siginfo->ksiginfo.signo)
/* Keep ascending signal order and FIFO order for equal signals. */
if (idx->ksiginfo.signo > siginfo->ksiginfo.signo)
{
rt_list_insert_after(&idx->node, &siginfo->node);
rt_list_insert_before(&idx->node, &siginfo->node);
inserted = RT_TRUE;
break;
}
Expand Down
Loading