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binfmt: Update the TLS pid when exec() swaps the pids.

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exec() swaps the pids of the caller and the new task, so that the new
program keeps the pid of the caller.  exec_swap() changes tcb->pid and
group->tg_pid.  But getpid() and gettid() read the copies in TLS,
tg_info->ta_pid and tl_tid, and exec_swap() does not change them.  So
getpid() in the new program returns the pid that the caller has now, and
kill(getpid(), sig) sends the signal to the caller.

Make exec_swap() update both copies for both tasks.  The address
environment of the new task is current in exec_swap().  The TLS of the
caller is in the address environment of the caller, so exec_swap()
selects that environment for the update of the caller.

Assisted-by: Claude Code:claude-opus-5-5
Signed-off-by: Marco Casaroli <marco.casaroli@gmail.com>
This commit is contained in:
Marco Casaroli 2026-10-06 18:15:38 +02:00 • committed by Xiang Xiao
parent 7fff8b746b
commit c642e99b34
1 changed files with 26 additions and 0 deletions
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26
binfmt/binfmt_execmodule.c
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@ -39,6 +39,7 @@
#include <nuttx/fs/fs.h>
#include <nuttx/kmalloc.h>
#include <nuttx/sched.h>
#include <nuttx/tls.h>
#include <sched/sched.h>
#include <task/spawn.h>
#include <nuttx/spawn.h>
@ -78,6 +79,10 @@ static void exec_swap(FAR struct tcb_s *ptcb, FAR struct tcb_s *chtcb)
int chndx;
pid_t pid;
irqstate_t flags;
FAR struct tls_info_s *info;
#if defined(CONFIG_ARCH_ADDRENV) && defined(CONFIG_BUILD_KERNEL)
FAR struct addrenv_s *oldenv;
#endif
#ifdef CONFIG_SCHED_HAVE_PARENT
# ifdef CONFIG_SCHED_CHILD_STATUS
FAR struct child_status_s *tg_children;
@ -131,6 +136,27 @@ static void exec_swap(FAR struct tcb_s *ptcb, FAR struct tcb_s *chtcb)
#endif
leave_critical_section(flags);
/* getpid() and gettid() read copies of the pids in TLS. The address
* environment of the child is current here, and the TLS of the caller
* is in its own.
*/
info = (FAR struct tls_info_s *)chtcb->stack_alloc_ptr;
info->tl_tid = chtcb->pid;
chtcb->group->tg_info->ta_pid = chtcb->group->tg_pid;
#if defined(CONFIG_ARCH_ADDRENV) && defined(CONFIG_BUILD_KERNEL)
addrenv_select(ptcb->addrenv_own, &oldenv);
#endif
info = (FAR struct tls_info_s *)ptcb->stack_alloc_ptr;
info->tl_tid = ptcb->pid;
ptcb->group->tg_info->ta_pid = ptcb->group->tg_pid;
#if defined(CONFIG_ARCH_ADDRENV) && defined(CONFIG_BUILD_KERNEL)
addrenv_restore(oldenv);
#endif
}
/****************************************************************************