In message <202110150823.19f8ner9047...@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 <d...@semihalf.com>
> AuthorDate: 2021-10-13 19:01:08 +0000
> Commit:     Marcin Wojtas <m...@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?


-- 
Cheers,
Cy Schubert <cy.schub...@cschubert.com>
FreeBSD UNIX:  <c...@freebsd.org>   Web:  https://FreeBSD.org
NTP:           <c...@nwtime.org>    Web:  https://nwtime.org

        The need of the many outweighs the greed of the few.




Reply via email to