From: Vlastimil Babka <vbabka@suse.cz> To: Michal Hocko <mhocko@kernel.org>, LKML <linux-kernel@vger.kernel.org> Cc: "Andrew Morton" <akpm@linux-foundation.org>, linux-mm@kvack.org, "Alex Deucher" <alexander.deucher@amd.com>, "Alex Thorlton" <athorlton@sgi.com>, "Andrea Arcangeli" <aarcange@redhat.com>, "Andy Lutomirski" <luto@amacapital.net>, "Benjamin LaHaise" <bcrl@kvack.org>, "Christian König" <christian.koenig@amd.com>, "Daniel Vetter" <daniel.vetter@intel.com>, "Dave Hansen" <dave.hansen@linux.intel.com>, "David Airlie" <airlied@linux.ie>, "Davidlohr Bueso" <dave@stgolabs.net>, "David Rientjes" <rientjes@google.com>, "H . Peter Anvin" <hpa@zytor.com>, "Hugh Dickins" <hughd@google.com>, "Ingo Molnar" <mingo@kernel.org>, "Johannes Weiner" <hannes@cmpxchg.org>, "Kirill A . Shutemov" <kirill.shutemov@linux.intel.com>, "Konstantin Khlebnikov" <koct9i@gmail.com>, linux-arch@vger.kernel.org, "Mel Gorman" <mgorman@suse.de>, "Oleg Nesterov" <oleg@redhat.com>, "Peter Zijlstra" <peterz@infradead.org> Subject: Re: [PATCH 04/18] mm, aout: handle vm_brk failures Date: Fri, 11 Mar 2016 11:32:42 +0100 [thread overview] Message-ID: <56E29ECA.5050809@suse.cz> (raw) In-Reply-To: <1456752417-9626-5-git-send-email-mhocko@kernel.org> On 02/29/2016 02:26 PM, Michal Hocko wrote: > From: Michal Hocko <mhocko@suse.com> > > vm_brk is allowed to fail but load_aout_binary simply ignores the error > and happily continues. I haven't noticed any problem from that in real > life but later patches will make the failure more likely because > vm_brk will become killable (resp. mmap_sem for write waiting will become > killable) so we should be more careful now. > > The error handling should be quite straightforward because there are > calls to vm_mmap which check the error properly already. The only > notable exception is set_brk which is called after beyond_if label. > But nothing indicates that we cannot move it above set_binfmt as the two > do not depend on each other and fail before we do set_binfmt and alter > reference counting. > > Cc: Thomas Gleixner <tglx@linutronix.de> > Cc: Ingo Molnar <mingo@redhat.com> > Cc: "H. Peter Anvin" <hpa@zytor.com> > Cc: Alexander Viro <viro@zeniv.linux.org.uk> > Signed-off-by: Michal Hocko <mhocko@suse.com> Acked--by: Vlastimil Babka <vbabka@suse.cz> [...] > @@ -378,7 +381,9 @@ static int load_aout_library(struct file *file) > "N_TXTOFF is not page aligned. Please convert library: %pD\n", > file); > } > - vm_brk(start_addr, ex.a_text + ex.a_data + ex.a_bss); > + retval = vm_brk(start_addr, ex.a_text + ex.a_data + ex.a_bss); > + if (IS_ERR_VALUE(retval)) > + goto out; > You could have removed the extra whitespace on the line above, which my vim so prominently highlights :) > read_code(file, start_addr, N_TXTOFF(ex), > ex.a_text + ex.a_data); >
WARNING: multiple messages have this Message-ID (diff)
From: Vlastimil Babka <vbabka@suse.cz> To: Michal Hocko <mhocko@kernel.org>, LKML <linux-kernel@vger.kernel.org> Cc: "Andrew Morton" <akpm@linux-foundation.org>, linux-mm@kvack.org, "Alex Deucher" <alexander.deucher@amd.com>, "Alex Thorlton" <athorlton@sgi.com>, "Andrea Arcangeli" <aarcange@redhat.com>, "Andy Lutomirski" <luto@amacapital.net>, "Benjamin LaHaise" <bcrl@kvack.org>, "Christian König" <christian.koenig@amd.com>, "Daniel Vetter" <daniel.vetter@intel.com>, "Dave Hansen" <dave.hansen@linux.intel.com>, "David Airlie" <airlied@linux.ie>, "Davidlohr Bueso" <dave@stgolabs.net>, "David Rientjes" <rientjes@google.com>, "H . Peter Anvin" <hpa@zytor.com>, "Hugh Dickins" <hughd@google.com>, "Ingo Molnar" <mingo@kernel.org>, "Johannes Weiner" <hannes@cmpxchg.org>, "Kirill A . Shutemov" <kirill.shutemov@linux.intel.com>, "Konstantin Khlebnikov" <koct9i@gmail.com>, linux-arch@vger.kernel.org, "Mel Gorman" <mgorman@suse.de>, "Oleg Nesterov" <oleg@redhat.com>, "Peter Zijlstra" <peterz@infradead.org>, "Petr Cermak" <petrcermak@chromium.org>, "Thomas Gleixner" <tglx@linutronix.de>, "Michal Hocko" <mhocko@suse.com>, "Ingo Molnar" <mingo@redhat.com>, "Alexander Viro" <viro@zeniv.linux.org.uk> Subject: Re: [PATCH 04/18] mm, aout: handle vm_brk failures Date: Fri, 11 Mar 2016 11:32:42 +0100 [thread overview] Message-ID: <56E29ECA.5050809@suse.cz> (raw) Message-ID: <20160311103242.7ehxcxLgFbe1Yf8n-BJSFpF_-JUvvj3iiwxBTUkUbFI@z> (raw) In-Reply-To: <1456752417-9626-5-git-send-email-mhocko@kernel.org> On 02/29/2016 02:26 PM, Michal Hocko wrote: > From: Michal Hocko <mhocko@suse.com> > > vm_brk is allowed to fail but load_aout_binary simply ignores the error > and happily continues. I haven't noticed any problem from that in real > life but later patches will make the failure more likely because > vm_brk will become killable (resp. mmap_sem for write waiting will become > killable) so we should be more careful now. > > The error handling should be quite straightforward because there are > calls to vm_mmap which check the error properly already. The only > notable exception is set_brk which is called after beyond_if label. > But nothing indicates that we cannot move it above set_binfmt as the two > do not depend on each other and fail before we do set_binfmt and alter > reference counting. > > Cc: Thomas Gleixner <tglx@linutronix.de> > Cc: Ingo Molnar <mingo@redhat.com> > Cc: "H. Peter Anvin" <hpa@zytor.com> > Cc: Alexander Viro <viro@zeniv.linux.org.uk> > Signed-off-by: Michal Hocko <mhocko@suse.com> Acked--by: Vlastimil Babka <vbabka@suse.cz> [...] > @@ -378,7 +381,9 @@ static int load_aout_library(struct file *file) > "N_TXTOFF is not page aligned. Please convert library: %pD\n", > file); > } > - vm_brk(start_addr, ex.a_text + ex.a_data + ex.a_bss); > + retval = vm_brk(start_addr, ex.a_text + ex.a_data + ex.a_bss); > + if (IS_ERR_VALUE(retval)) > + goto out; > You could have removed the extra whitespace on the line above, which my vim so prominently highlights :) > read_code(file, start_addr, N_TXTOFF(ex), > ex.a_text + ex.a_data); >
next prev parent reply other threads:[~2016-03-11 10:32 UTC|newest] Thread overview: 138+ messages / expand[flat|nested] mbox.gz Atom feed top 2016-02-29 13:26 [PATCH 0/18] change mmap_sem taken for write killable Michal Hocko 2016-02-29 13:26 ` Michal Hocko 2016-02-29 13:26 ` [PATCH 01/18] mm: Make mmap_sem for write waits killable for mm syscalls Michal Hocko 2016-02-29 13:26 ` Michal Hocko 2016-02-29 13:44 ` kbuild test robot 2016-02-29 13:44 ` kbuild test robot 2016-02-29 13:44 ` kbuild test robot 2016-02-29 13:44 ` kbuild test robot 2016-03-10 15:47 ` Vlastimil Babka 2016-03-10 15:47 ` Vlastimil Babka 2016-03-10 15:56 ` Michal Hocko 2016-03-10 15:56 ` Michal Hocko 2016-02-29 13:26 ` [PATCH 02/18] mm: make vm_mmap killable Michal Hocko 2016-02-29 13:26 ` Michal Hocko 2016-03-11 9:59 ` Vlastimil Babka 2016-03-11 9:59 ` Vlastimil Babka 2016-03-11 12:12 ` Michal Hocko 2016-03-11 12:12 ` Michal Hocko 2016-03-11 12:43 ` Vlastimil Babka 2016-03-11 12:43 ` Vlastimil Babka 2016-03-11 12:55 ` Michal Hocko 2016-03-11 12:55 ` Michal Hocko 2016-02-29 13:26 ` [PATCH 03/18] mm: make vm_munmap killable Michal Hocko 2016-02-29 13:26 ` Michal Hocko 2016-03-11 10:06 ` Vlastimil Babka 2016-03-11 10:06 ` Vlastimil Babka 2016-03-11 12:32 ` Michal Hocko 2016-03-11 12:32 ` Michal Hocko 2016-02-29 13:26 ` [PATCH 04/18] mm, aout: handle vm_brk failures Michal Hocko 2016-02-29 13:26 ` Michal Hocko 2016-03-11 10:32 ` Vlastimil Babka [this message] 2016-03-11 10:32 ` Vlastimil Babka 2016-03-11 12:42 ` Michal Hocko 2016-03-11 12:42 ` Michal Hocko 2016-02-29 13:26 ` [PATCH 05/18] mm, elf: handle vm_brk error Michal Hocko 2016-02-29 13:26 ` Michal Hocko 2016-03-11 10:35 ` Vlastimil Babka 2016-03-11 10:35 ` Vlastimil Babka 2016-02-29 13:26 ` [PATCH 06/18] mm: make vm_brk killable Michal Hocko 2016-02-29 13:26 ` Michal Hocko 2016-03-11 10:44 ` Vlastimil Babka 2016-03-11 10:44 ` Vlastimil Babka 2016-02-29 13:26 ` [PATCH 07/18] mm, proc: make clear_refs killable Michal Hocko 2016-02-29 13:26 ` Michal Hocko 2016-02-29 13:47 ` kbuild test robot 2016-02-29 13:47 ` kbuild test robot 2016-02-29 17:38 ` Oleg Nesterov 2016-02-29 17:38 ` Oleg Nesterov 2016-02-29 17:53 ` Michal Hocko 2016-02-29 17:53 ` Michal Hocko 2016-02-29 17:58 ` Oleg Nesterov 2016-02-29 17:58 ` Oleg Nesterov 2016-02-29 18:02 ` Michal Hocko 2016-02-29 18:02 ` Michal Hocko 2016-02-29 13:26 ` [PATCH 08/18] mm, fork: make dup_mmap wait for mmap_sem for write killable Michal Hocko 2016-02-29 13:26 ` Michal Hocko 2016-02-29 13:48 ` kbuild test robot 2016-02-29 13:48 ` kbuild test robot 2016-02-29 17:54 ` Oleg Nesterov 2016-02-29 17:54 ` Oleg Nesterov 2016-02-29 13:26 ` [PATCH 09/18] ipc, shm: make shmem attach/detach wait for mmap_sem killable Michal Hocko 2016-02-29 13:26 ` Michal Hocko 2016-03-08 19:15 ` Davidlohr Bueso 2016-03-08 19:15 ` Davidlohr Bueso 2016-03-09 10:16 ` Michal Hocko 2016-03-09 10:16 ` Michal Hocko 2016-02-29 13:26 ` [PATCH 10/18] vdso: make arch_setup_additional_pages wait for mmap_sem for write killable Michal Hocko 2016-02-29 13:26 ` Michal Hocko 2016-02-29 13:45 ` kbuild test robot 2016-02-29 13:45 ` kbuild test robot 2016-02-29 13:50 ` kbuild test robot 2016-02-29 13:50 ` kbuild test robot 2016-02-29 13:53 ` kbuild test robot 2016-02-29 13:53 ` kbuild test robot 2016-02-29 15:41 ` Andy Lutomirski 2016-02-29 15:41 ` Andy Lutomirski 2016-03-11 11:28 ` Vlastimil Babka 2016-03-11 11:28 ` Vlastimil Babka 2016-02-29 13:26 ` [PATCH 11/18] coredump: make coredump_wait wait for mma_sem " Michal Hocko 2016-02-29 13:26 ` Michal Hocko 2016-02-29 15:57 ` Oleg Nesterov 2016-02-29 15:57 ` Oleg Nesterov 2016-03-11 11:32 ` Vlastimil Babka 2016-03-11 11:32 ` Vlastimil Babka 2016-03-11 11:54 ` Vlastimil Babka 2016-03-11 11:54 ` Vlastimil Babka 2016-03-11 12:46 ` Michal Hocko 2016-03-11 12:46 ` Michal Hocko 2016-02-29 13:26 ` [PATCH 12/18] aio: make aio_setup_ring killable Michal Hocko 2016-02-29 13:26 ` Michal Hocko 2016-02-29 16:17 ` Jeff Moyer 2016-02-29 16:17 ` Jeff Moyer 2016-03-11 11:57 ` Vlastimil Babka 2016-03-11 11:57 ` Vlastimil Babka 2016-02-29 13:26 ` [PATCH 13/18] exec: make exec path waiting for mmap_sem killable Michal Hocko 2016-02-29 13:26 ` Michal Hocko 2016-02-29 17:23 ` Oleg Nesterov 2016-02-29 17:23 ` Oleg Nesterov 2016-02-29 17:47 ` Michal Hocko 2016-02-29 17:47 ` Michal Hocko 2016-02-29 18:10 ` Oleg Nesterov 2016-02-29 18:10 ` Oleg Nesterov 2016-03-11 12:51 ` Vlastimil Babka 2016-03-11 12:51 ` Vlastimil Babka 2016-02-29 13:26 ` [PATCH 14/18] prctl: make PR_SET_THP_DISABLE wait " Michal Hocko 2016-02-29 13:26 ` Michal Hocko 2016-03-11 12:54 ` Vlastimil Babka 2016-03-11 12:54 ` Vlastimil Babka 2016-02-29 13:26 ` [PATCH 15/18] uprobes: wait for mmap_sem for write killable Michal Hocko 2016-02-29 13:26 ` Michal Hocko 2016-02-29 15:57 ` Oleg Nesterov 2016-02-29 15:57 ` Oleg Nesterov 2016-02-29 16:28 ` Michal Hocko 2016-02-29 16:28 ` Michal Hocko 2016-02-29 17:12 ` Oleg Nesterov 2016-02-29 17:12 ` Oleg Nesterov 2016-02-29 13:26 ` [PATCH 16/18] drm/i915: make i915_gem_mmap_ioctl wait for mmap_sem killable Michal Hocko 2016-02-29 13:26 ` Michal Hocko 2016-03-11 15:23 ` Vlastimil Babka 2016-03-11 15:23 ` Vlastimil Babka 2016-02-29 13:26 ` [PATCH 17/18] drm/radeon: make radeon_mn_get " Michal Hocko 2016-02-29 13:26 ` Michal Hocko 2016-02-29 13:35 ` Christian König 2016-02-29 13:35 ` Christian König 2016-03-11 15:27 ` Vlastimil Babka 2016-03-11 15:27 ` Vlastimil Babka 2016-02-29 13:26 ` [PATCH 18/18] drm/amdgpu: make amdgpu_mn_get " Michal Hocko 2016-02-29 13:26 ` Michal Hocko 2016-03-11 15:29 ` Vlastimil Babka 2016-03-11 15:29 ` Vlastimil Babka 2016-02-29 13:31 ` [PATCH 0/18] change mmap_sem taken for write killable Michal Hocko 2016-02-29 13:31 ` Michal Hocko 2016-02-29 14:04 ` Kirill A. Shutemov 2016-02-29 14:04 ` Kirill A. Shutemov 2016-02-29 14:16 ` Michal Hocko 2016-02-29 14:16 ` Michal Hocko 2016-02-29 15:03 ` Kirill A. Shutemov 2016-02-29 15:03 ` Kirill A. Shutemov
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