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author | Linus Torvalds <torvalds@linux-foundation.org> | 2016-10-19 08:39:47 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2016-10-19 08:39:47 -0700 |
commit | 63ae602cea637ee4a6490d940c0da5d78bd0bbe0 (patch) | |
tree | 5da1eec3756fec9d62455c498442944a7f35149b /arch/alpha | |
parent | 1a1891d762d6e64daf07b5be4817e3fbb29e3c59 (diff) | |
parent | f307ab6dcea03f9d8e4d70508fd7d1ca57cfa7f9 (diff) | |
download | linux-stable-63ae602cea637ee4a6490d940c0da5d78bd0bbe0.tar.gz linux-stable-63ae602cea637ee4a6490d940c0da5d78bd0bbe0.tar.bz2 linux-stable-63ae602cea637ee4a6490d940c0da5d78bd0bbe0.zip |
Merge branch 'gup_flag-cleanups'
Merge the gup_flags cleanups from Lorenzo Stoakes:
"This patch series adjusts functions in the get_user_pages* family such
that desired FOLL_* flags are passed as an argument rather than
implied by flags.
The purpose of this change is to make the use of FOLL_FORCE explicit
so it is easier to grep for and clearer to callers that this flag is
being used. The use of FOLL_FORCE is an issue as it overrides missing
VM_READ/VM_WRITE flags for the VMA whose pages we are reading
from/writing to, which can result in surprising behaviour.
The patch series came out of the discussion around commit 38e088546522
("mm: check VMA flags to avoid invalid PROT_NONE NUMA balancing"),
which addressed a BUG_ON() being triggered when a page was faulted in
with PROT_NONE set but having been overridden by FOLL_FORCE.
do_numa_page() was run on the assumption the page _must_ be one marked
for NUMA node migration as an actual PROT_NONE page would have been
dealt with prior to this code path, however FOLL_FORCE introduced a
situation where this assumption did not hold.
See
https://marc.info/?l=linux-mm&m=147585445805166
for the patch proposal"
Additionally, there's a fix for an ancient bug related to FOLL_FORCE and
FOLL_WRITE by me.
[ This branch was rebased recently to add a few more acked-by's and
reviewed-by's ]
* gup_flag-cleanups:
mm: replace access_process_vm() write parameter with gup_flags
mm: replace access_remote_vm() write parameter with gup_flags
mm: replace __access_remote_vm() write parameter with gup_flags
mm: replace get_user_pages_remote() write/force parameters with gup_flags
mm: replace get_user_pages() write/force parameters with gup_flags
mm: replace get_vaddr_frames() write/force parameters with gup_flags
mm: replace get_user_pages_locked() write/force parameters with gup_flags
mm: replace get_user_pages_unlocked() write/force parameters with gup_flags
mm: remove write/force parameters from __get_user_pages_unlocked()
mm: remove write/force parameters from __get_user_pages_locked()
mm: remove gup_flags FOLL_WRITE games from __get_user_pages()
Diffstat (limited to 'arch/alpha')
-rw-r--r-- | arch/alpha/kernel/ptrace.c | 9 |
1 files changed, 6 insertions, 3 deletions
diff --git a/arch/alpha/kernel/ptrace.c b/arch/alpha/kernel/ptrace.c index d9ee81769899..940dfb406591 100644 --- a/arch/alpha/kernel/ptrace.c +++ b/arch/alpha/kernel/ptrace.c @@ -157,14 +157,16 @@ put_reg(struct task_struct *task, unsigned long regno, unsigned long data) static inline int read_int(struct task_struct *task, unsigned long addr, int * data) { - int copied = access_process_vm(task, addr, data, sizeof(int), 0); + int copied = access_process_vm(task, addr, data, sizeof(int), + FOLL_FORCE); return (copied == sizeof(int)) ? 0 : -EIO; } static inline int write_int(struct task_struct *task, unsigned long addr, int data) { - int copied = access_process_vm(task, addr, &data, sizeof(int), 1); + int copied = access_process_vm(task, addr, &data, sizeof(int), + FOLL_FORCE | FOLL_WRITE); return (copied == sizeof(int)) ? 0 : -EIO; } @@ -281,7 +283,8 @@ long arch_ptrace(struct task_struct *child, long request, /* When I and D space are separate, these will need to be fixed. */ case PTRACE_PEEKTEXT: /* read word at location addr. */ case PTRACE_PEEKDATA: - copied = access_process_vm(child, addr, &tmp, sizeof(tmp), 0); + copied = access_process_vm(child, addr, &tmp, sizeof(tmp), + FOLL_FORCE); ret = -EIO; if (copied != sizeof(tmp)) break; |