kernel.git/arch/sh/kernel/vsyscall/vsyscall.c, branch master

sysctl: Fix underflow value setting risk in vm_table

2025-02-17T10:33:46Z

Commit 3b3376f222e3 ("sysctl.c: fix underflow value setting risk in vm_table") fixes underflow value setting risk in vm_table but misses vdso_enabled sysctl. vdso_enabled sysctl is initialized with .extra1 value as SYSCTL_ZERO to avoid negative value writes but the proc_handler is proc_dointvec and not proc_dointvec_minmax and thus do not uses .extra1 and .extra2. The following command thus works : `# echo -1 > /proc/sys/vm/vdso_enabled` This patch properly sets the proc_handler to proc_dointvec_minmax. In addition to .extra1, .extra2 is set to SYSCTL_ONE. The sysctl is thus bounded between 0 and 1. Fixes: 3b3376f222e3 ("sysctl.c: fix underflow value setting risk in vm_table") Signed-off-by: Nicolas Bouchinet Reviewed-by: Jan Kara Reviewed-by: Kees Cook Signed-off-by: Joel Granados

sh: vdso: move the sysctl to arch/sh/kernel/vsyscall/vsyscall.c

2025-02-07T15:53:04Z

When CONFIG_SUPERH and CONFIG_VSYSCALL are defined, vdso_enabled belongs to arch/sh/kernel/vsyscall/vsyscall.c. So, move it into its own file. To avoid failure when registering the vdso_table, move the call to register_sysctl_init() into its own fs_initcall(). Signed-off-by: Kaixiong Yu Reviewed-by: Kees Cook Signed-off-by: Joel Granados

mm: remove legacy install_special_mapping() code

2024-09-02T03:26:13Z

All relevant architectures had already been converted to the new interface (which just has an underscore in front of the name - not very imaginative naming), this just force-converts the stragglers. The modern interface is almost identical to the old one, except instead of the page pointer it takes a "struct vm_special_mapping" that describes the mapping (and contains the page pointer as one member), and it returns the resulting 'vma' instead of just the error code. Getting rid of the old interface also gets rid of some special casing, which had caused problems with the mremap extensions to "struct vm_special_mapping". [akpm@linux-foundation.org: coding-style cleanups] Link: https://lkml.kernel.org/r/CAHk-=whvR+z=0=0gzgdfUiK70JTa-=+9vxD-4T=3BagXR6dciA@mail.gmail.comTested-by: Rob Landley # arch/sh/ Link: https://lore.kernel.org/all/20240819195120.GA1113263@thelio-3990X/ Signed-off-by: Linus Torvalds Cc: Nathan Chancellor Cc: Michael Ellerman Cc: Anton Ivanov Cc: Brian Cain Cc: Christophe Leroy Cc: Dinh Nguyen Cc: Guo Ren Cc: Jeff Xu Cc: Johannes Berg Cc: John Paul Adrian Glaubitz Cc: Liam R. Howlett Cc: Nicholas Piggin Cc: Pedro Falcato Cc: Richard Weinberger Cc: Rich Felker Cc: Rob Landley Cc: Yoshinori Sato Signed-off-by: Andrew Morton

mmap locking API: use coccinelle to convert mmap_sem rwsem call sites

2020-06-09T16:39:14Z

This change converts the existing mmap_sem rwsem calls to use the new mmap locking API instead. The change is generated using coccinelle with the following rule: // spatch --sp-file mmap_lock_api.cocci --in-place --include-headers --dir . @@ expression mm; @@ ( -init_rwsem +mmap_init_lock | -down_write +mmap_write_lock | -down_write_killable +mmap_write_lock_killable | -down_write_trylock +mmap_write_trylock | -up_write +mmap_write_unlock | -downgrade_write +mmap_write_downgrade | -down_read +mmap_read_lock | -down_read_killable +mmap_read_lock_killable | -down_read_trylock +mmap_read_trylock | -up_read +mmap_read_unlock ) -(&mm->mmap_sem) +(mm) Signed-off-by: Michel Lespinasse Signed-off-by: Andrew Morton Reviewed-by: Daniel Jordan Reviewed-by: Laurent Dufour Reviewed-by: Vlastimil Babka Cc: Davidlohr Bueso Cc: David Rientjes Cc: Hugh Dickins Cc: Jason Gunthorpe Cc: Jerome Glisse Cc: John Hubbard Cc: Liam Howlett Cc: Matthew Wilcox Cc: Peter Zijlstra Cc: Ying Han Link: http://lkml.kernel.org/r/20200520052908.204642-5-walken@google.com Signed-off-by: Linus Torvalds

sh: kernel: convert to SPDX identifiers

2018-12-28T20:11:45Z

Update license to use SPDX-License-Identifier instead of verbose license text. Link: http://lkml.kernel.org/r/8736rccswn.wl-kuninori.morimoto.gx@renesas.com Signed-off-by: Kuninori Morimoto Reviewed-by: Simon Horman Cc: Rich Felker Cc: Yoshinori Sato Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

vdso: make arch_setup_additional_pages wait for mmap_sem for write killable

2016-05-24T00:04:14Z

most architectures are relying on mmap_sem for write in their arch_setup_additional_pages. If the waiting task gets killed by the oom killer it would block oom_reaper from asynchronous address space reclaim and reduce the chances of timely OOM resolving. Wait for the lock in the killable mode and return with EINTR if the task got killed while waiting. Signed-off-by: Michal Hocko Acked-by: Andy Lutomirski [x86 vdso] Acked-by: Vlastimil Babka Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

arm64,ia64,ppc,s390,sh,tile,um,x86,mm: remove default gate area

2014-08-08T22:57:27Z

The core mm code will provide a default gate area based on FIXADDR_USER_START and FIXADDR_USER_END if !defined(__HAVE_ARCH_GATE_AREA) && defined(AT_SYSINFO_EHDR). This default is only useful for ia64. arm64, ppc, s390, sh, tile, 64-bit UML, and x86_32 have their own code just to disable it. arm, 32-bit UML, and x86_64 have gate areas, but they have their own implementations. This gets rid of the default and moves the code into ia64. This should save some code on architectures without a gate area: it's now possible to inline the gate_area functions in the default case. Signed-off-by: Andy Lutomirski Acked-by: Nathan Lynch Acked-by: H. Peter Anvin Acked-by: Benjamin Herrenschmidt [in principle] Acked-by: Richard Weinberger [for um] Acked-by: Will Deacon [for arm64] Cc: Catalin Marinas Cc: Will Deacon Cc: Tony Luck Cc: Fenghua Yu Cc: Benjamin Herrenschmidt Cc: Paul Mackerras Cc: Martin Schwidefsky Cc: Heiko Carstens Cc: Chris Metcalf Cc: Jeff Dike Cc: Richard Weinberger Cc: Thomas Gleixner Cc: Ingo Molnar Cc: "H. Peter Anvin" Cc: Nathan Lynch Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

coredump: remove VM_ALWAYSDUMP flag

2012-03-23T23:58:42Z

The motivation for this patchset was that I was looking at a way for a qemu-kvm process, to exclude the guest memory from its core dump, which can be quite large. There are already a number of filter flags in /proc//coredump_filter, however, these allow one to specify 'types' of kernel memory, not specific address ranges (which is needed in this case). Since there are no more vma flags available, the first patch eliminates the need for the 'VM_ALWAYSDUMP' flag. The flag is used internally by the kernel to mark vdso and vsyscall pages. However, it is simple enough to check if a vma covers a vdso or vsyscall page without the need for this flag. The second patch then replaces the 'VM_ALWAYSDUMP' flag with a new 'VM_NODUMP' flag, which can be set by userspace using new madvise flags: 'MADV_DONTDUMP', and unset via 'MADV_DODUMP'. The core dump filters continue to work the same as before unless 'MADV_DONTDUMP' is set on the region. The qemu code which implements this features is at: http://people.redhat.com/~jbaron/qemu-dump/qemu-dump.patch In my testing the qemu core dump shrunk from 383MB -> 13MB with this patch. I also believe that the 'MADV_DONTDUMP' flag might be useful for security sensitive apps, which might want to select which areas are dumped. This patch: The VM_ALWAYSDUMP flag is currently used by the coredump code to indicate that a vma is part of a vsyscall or vdso section. However, we can determine if a vma is in one these sections by checking it against the gate_vma and checking for a non-NULL return value from arch_vma_name(). Thus, freeing a valuable vma bit. Signed-off-by: Jason Baron Acked-by: Roland McGrath Cc: Chris Metcalf Cc: Avi Kivity Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

mm: arch: rename in_gate_area_no_task to in_gate_area_no_mm

2011-03-23T20:36:55Z

Now that gate vma's are referenced with respect to a particular mm and not a particular task it only makes sense to propagate the change to this predicate as well. Signed-off-by: Stephen Wilson Reviewed-by: Michel Lespinasse Cc: Thomas Gleixner Cc: Ingo Molnar Cc: "H. Peter Anvin" Signed-off-by: Al Viro

mm: arch: make in_gate_area take an mm_struct instead of a task_struct

2011-03-23T20:36:54Z

Morally, the question of whether an address lies in a gate vma should be asked with respect to an mm, not a particular task. Moreover, dropping the dependency on task_struct will help make existing and future operations on mm's more flexible and convenient. Signed-off-by: Stephen Wilson Reviewed-by: Michel Lespinasse Cc: Thomas Gleixner Cc: Ingo Molnar Cc: "H. Peter Anvin" Signed-off-by: Al Viro