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authorLinus Torvalds <torvalds@linux-foundation.org>2016-10-19 08:39:47 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2016-10-19 08:39:47 -0700
commit63ae602cea637ee4a6490d940c0da5d78bd0bbe0 (patch)
tree5da1eec3756fec9d62455c498442944a7f35149b /arch/alpha
parent1a1891d762d6e64daf07b5be4817e3fbb29e3c59 (diff)
parentf307ab6dcea03f9d8e4d70508fd7d1ca57cfa7f9 (diff)
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.c9
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;