From 8576a4ebaa313addc9415078d2610ae6f52247ba Mon Sep 17 00:00:00 2001 From: dchagin Date: Sun, 17 Jul 2016 15:07:33 +0000 Subject: MFC r302515: Implement Linux personality() system call mainly due to READ_IMPLIES_EXEC flag. In Linux if this flag is set, PROT_READ implies PROT_EXEC for mmap(). Linux/i386 set this flag automatically if the binary requires executable stack. READ_IMPLIES_EXEC flag will be used in the next Linux mmap() commit. --- sys/compat/linux/linux_emul.c | 17 ++++++++++++++++- 1 file changed, 16 insertions(+), 1 deletion(-) (limited to 'sys/compat/linux/linux_emul.c') diff --git a/sys/compat/linux/linux_emul.c b/sys/compat/linux/linux_emul.c index c2bf3ae..b244eea 100644 --- a/sys/compat/linux/linux_emul.c +++ b/sys/compat/linux/linux_emul.c @@ -45,6 +45,7 @@ __FBSDID("$FreeBSD$"); #include #include +#include #include @@ -127,7 +128,7 @@ linux_proc_init(struct thread *td, struct thread *newtd, int flags) /* epoll should be destroyed in a case of exec. */ pem = pem_find(p); KASSERT(pem != NULL, ("proc_exit: proc emuldata not found.\n")); - + pem->persona = 0; if (pem->epoll != NULL) { emd = pem->epoll; pem->epoll = NULL; @@ -220,6 +221,9 @@ linux_proc_exec(void *arg __unused, struct proc *p, struct image_params *imgp) { struct thread *td = curthread; struct thread *othertd; +#if defined(__amd64__) + struct linux_pemuldata *pem; +#endif /* * In a case of execing from linux binary properly detach @@ -243,6 +247,17 @@ linux_proc_exec(void *arg __unused, struct proc *p, struct image_params *imgp) linux_proc_init(td, NULL, 0); else linux_proc_init(td, td, 0); +#if defined(__amd64__) + /* + * An IA32 executable which has executable stack will have the + * READ_IMPLIES_EXEC personality flag set automatically. + */ + if (SV_PROC_FLAG(td->td_proc, SV_ILP32) && + imgp->stack_prot & VM_PROT_EXECUTE) { + pem = pem_find(p); + pem->persona |= LINUX_READ_IMPLIES_EXEC; + } +#endif } } -- cgit v1.1