Re: git: 889b56c8cd84 - main - setrlimit: Take stack gap into account.
Date: Mon, 18 Oct 2021 11:02:52 UTC
Hi Cy,
sob., 16 paź 2021 o 18:02 Cy Schubert <Cy.Schubert@cschubert.com> napisał(a):
>
> In message <202110150823.19F8NEr9047194@gitrepo.freebsd.org>, Marcin Wojtas
> wri
> tes:
> > The branch main has been updated by mw:
> >
> > URL: https://cgit.FreeBSD.org/src/commit/?id=889b56c8cd84c9a9f2d9e3b019c154d6
> > f14d9021
> >
> > commit 889b56c8cd84c9a9f2d9e3b019c154d6f14d9021
> > Author: Dawid Gorecki <dgr@semihalf.com>
> > AuthorDate: 2021-10-13 19:01:08 +0000
> > Commit: Marcin Wojtas <mw@FreeBSD.org>
> > CommitDate: 2021-10-15 08:21:47 +0000
> >
> > setrlimit: Take stack gap into account.
> >
> > Calling setrlimit with stack gap enabled and with low values of stack
> > resource limit often caused the program to abort immediately after
> > exiting the syscall. This happened due to the fact that the resource
> > limit was calculated assuming that the stack started at sv_usrstack,
> > while with stack gap enabled the stack is moved by a random number
> > of bytes.
> >
> > Save information about stack size in struct vmspace and adjust the
> > rlim_cur value. If the rlim_cur and stack gap is bigger than rlim_max,
> > then the value is truncated to rlim_max.
> >
> > PR: 253208
> > Reviewed by: kib
> > Obtained from: Semihalf
> > Sponsored by: Stormshield
> > MFC after: 1 month
> > Differential Revision: https://reviews.freebsd.org/D31516
> > ---
> > sys/kern/imgact_elf.c | 5 +++--
> > sys/kern/kern_exec.c | 11 ++++++++---
> > sys/kern/kern_resource.c | 3 +++
> > sys/sys/imgact_elf.h | 2 +-
> > sys/sys/sysent.h | 2 +-
> > sys/vm/vm_map.c | 2 ++
> > sys/vm/vm_map.h | 1 +
> > 7 files changed, 19 insertions(+), 7 deletions(-)
> >
> > diff --git a/sys/kern/imgact_elf.c b/sys/kern/imgact_elf.c
> > index ef1edfcabaf0..898f0f66a532 100644
> > --- a/sys/kern/imgact_elf.c
> > +++ b/sys/kern/imgact_elf.c
> > @@ -2684,7 +2684,7 @@ __elfN(untrans_prot)(vm_prot_t prot)
> > return (flags);
> > }
> >
> > -void
> > +vm_size_t
> > __elfN(stackgap)(struct image_params *imgp, uintptr_t *stack_base)
> > {
> > uintptr_t range, rbase, gap;
> > @@ -2692,7 +2692,7 @@ __elfN(stackgap)(struct image_params *imgp, uintptr_t *
> > stack_base)
> >
> > pct = __elfN(aslr_stack_gap);
> > if (pct == 0)
> > - return;
> > + return (0);
> > if (pct > 50)
> > pct = 50;
> > range = imgp->eff_stack_sz * pct / 100;
> > @@ -2700,4 +2700,5 @@ __elfN(stackgap)(struct image_params *imgp, uintptr_t *
> > stack_base)
> > gap = rbase % range;
> > gap &= ~(sizeof(u_long) - 1);
> > *stack_base -= gap;
> > + return (gap);
> > }
> > diff --git a/sys/kern/kern_exec.c b/sys/kern/kern_exec.c
> > index 50e75fda6cfb..9dceebdd8441 100644
> > --- a/sys/kern/kern_exec.c
> > +++ b/sys/kern/kern_exec.c
> > @@ -1148,6 +1148,7 @@ exec_new_vmspace(struct image_params *imgp, struct syse
> > ntvec *sv)
> > stack_prot, error, vm_mmap_to_errno(error));
> > return (vm_mmap_to_errno(error));
> > }
> > + vmspace->vm_stkgap = 0;
> >
> > /*
> > * vm_ssize and vm_maxsaddr are somewhat antiquated concepts, but they
> > @@ -1493,12 +1494,16 @@ exec_args_get_begin_envv(struct image_args *args)
> > void
> > exec_stackgap(struct image_params *imgp, uintptr_t *dp)
> > {
> > + struct proc *p = imgp->proc;
> > +
> > if (imgp->sysent->sv_stackgap == NULL ||
> > - (imgp->proc->p_fctl0 & (NT_FREEBSD_FCTL_ASLR_DISABLE |
> > + (p->p_fctl0 & (NT_FREEBSD_FCTL_ASLR_DISABLE |
> > NT_FREEBSD_FCTL_ASG_DISABLE)) != 0 ||
> > - (imgp->map_flags & MAP_ASLR) == 0)
> > + (imgp->map_flags & MAP_ASLR) == 0) {
> > + p->p_vmspace->vm_stkgap = 0;
> > return;
> > - imgp->sysent->sv_stackgap(imgp, dp);
> > + }
> > + p->p_vmspace->vm_stkgap = imgp->sysent->sv_stackgap(imgp, dp);
> > }
> >
> > /*
> > diff --git a/sys/kern/kern_resource.c b/sys/kern/kern_resource.c
> > index 4c62961e1bc4..b556d4fded51 100644
> > --- a/sys/kern/kern_resource.c
> > +++ b/sys/kern/kern_resource.c
> > @@ -671,6 +671,9 @@ kern_proc_setrlimit(struct thread *td, struct proc *p, u_
> > int which,
> > if (limp->rlim_max < 0)
> > limp->rlim_max = RLIM_INFINITY;
> >
> > + if (which == RLIMIT_STACK && limp->rlim_cur != RLIM_INFINITY)
> > + limp->rlim_cur += p->p_vmspace->vm_stkgap;
> > +
> > oldssiz.rlim_cur = 0;
> > newlim = lim_alloc();
> > PROC_LOCK(p);
> > diff --git a/sys/sys/imgact_elf.h b/sys/sys/imgact_elf.h
> > index 97383c6eeeb8..294f17c87b6f 100644
> > --- a/sys/sys/imgact_elf.h
> > +++ b/sys/sys/imgact_elf.h
> > @@ -118,7 +118,7 @@ int __elfN(remove_brand_entry)(Elf_Brandinfo *entry
> > );
> > int __elfN(freebsd_fixup)(uintptr_t *, struct image_params *);
> > int __elfN(coredump)(struct thread *, struct vnode *, off_t, int);
> > size_t __elfN(populate_note)(int, void *, void *, size_t, void **);
> > -void __elfN(stackgap)(struct image_params *, uintptr_t *);
> > +vm_size_t __elfN(stackgap)(struct image_params *, uintptr_t *);
> > int __elfN(freebsd_copyout_auxargs)(struct image_params *, uintptr_t);
> > void __elfN(puthdr)(struct thread *, void *, size_t, int, size_t, int);
> > void __elfN(prepare_notes)(struct thread *, struct note_info_list *,
> > diff --git a/sys/sys/sysent.h b/sys/sys/sysent.h
> > index ad50bf56e87d..ea96c87a79af 100644
> > --- a/sys/sys/sysent.h
> > +++ b/sys/sys/sysent.h
> > @@ -119,7 +119,7 @@ struct sysentvec {
> > void (*sv_elf_core_prepare_notes)(struct thread *,
> > struct note_info_list *, size_t *);
> > int (*sv_imgact_try)(struct image_params *);
> > - void (*sv_stackgap)(struct image_params *, uintptr_t *);
> > + vm_size_t (*sv_stackgap)(struct image_params *, uintptr_t *);
> > int (*sv_copyout_auxargs)(struct image_params *,
> > uintptr_t);
> > int sv_minsigstksz; /* minimum signal stack size */
> > diff --git a/sys/vm/vm_map.c b/sys/vm/vm_map.c
> > index 1ac4ccf72f11..87a290b998b9 100644
> > --- a/sys/vm/vm_map.c
> > +++ b/sys/vm/vm_map.c
> > @@ -343,6 +343,7 @@ vmspace_alloc(vm_offset_t min, vm_offset_t max, pmap_pini
> > t_t pinit)
> > vm->vm_taddr = 0;
> > vm->vm_daddr = 0;
> > vm->vm_maxsaddr = 0;
> > + vm->vm_stkgap = 0;
> > return (vm);
> > }
> >
> > @@ -4265,6 +4266,7 @@ vmspace_fork(struct vmspace *vm1, vm_ooffset_t *fork_ch
> > arge)
> > vm2->vm_taddr = vm1->vm_taddr;
> > vm2->vm_daddr = vm1->vm_daddr;
> > vm2->vm_maxsaddr = vm1->vm_maxsaddr;
> > + vm2->vm_stkgap = vm1->vm_stkgap;
> > vm_map_lock(old_map);
> > if (old_map->busy)
> > vm_map_wait_busy(old_map);
> > diff --git a/sys/vm/vm_map.h b/sys/vm/vm_map.h
> > index ace205b21b42..873ff62eec4a 100644
> > --- a/sys/vm/vm_map.h
> > +++ b/sys/vm/vm_map.h
> > @@ -293,6 +293,7 @@ struct vmspace {
> > caddr_t vm_taddr; /* (c) user virtual address of text */
> > caddr_t vm_daddr; /* (c) user virtual address of data */
> > caddr_t vm_maxsaddr; /* user VA at max stack growth */
> > + vm_size_t vm_stkgap; /* stack gap size in bytes */
> > u_int vm_refcnt; /* number of references */
> > /*
> > * Keep the PMAP last, so that CPU-specific variations of that
> >
>
> Is it possible to have a __FreeBSD_version bump for ports?
>
>
At a first glance I don't see the ports' global versioning apart from
creating tags, but maybe ports' maintainers will have more insight.
Best regards,
Marcin