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Merge branch 'gup_flag-cleanups'

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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 38e0885465
  ("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()
This commit is contained in:
Linus Torvalds
2016-10-19 08:39:47 -07:00
parent 1a1891d762 f307ab6dce
commit 63ae602cea
61 changed files with 273 additions and 189 deletions
Download Patch File Download Diff File Expand all files Collapse all files

2
arch/ia64/kernel/err_inject.c
View File

@@ -142,7 +142,7 @@ store_virtual_to_phys(struct device *dev, struct device_attribute *attr,
u64 virt_addr=simple_strtoull(buf, NULL, 16);
int ret;
ret = get_user_pages(virt_addr, 1, VM_READ, 0, NULL, NULL);
ret = get_user_pages(virt_addr, 1, FOLL_WRITE, NULL, NULL);
if (ret<=0) {
#ifdef ERR_INJ_DEBUG
printk("Virtual address %lx is not existing.\n",virt_addr);

14
arch/ia64/kernel/ptrace.c
View File

@@ -453,7 +453,7 @@ ia64_peek (struct task_struct *child, struct switch_stack *child_stack,
return 0;
}
}
copied = access_process_vm(child, addr, &ret, sizeof(ret), 0);
copied = access_process_vm(child, addr, &ret, sizeof(ret), FOLL_FORCE);
if (copied != sizeof(ret))
return -EIO;
*val = ret;
@@ -489,7 +489,8 @@ ia64_poke (struct task_struct *child, struct switch_stack *child_stack,
*ia64_rse_skip_regs(krbs, regnum) = val;
}
}
} else if (access_process_vm(child, addr, &val, sizeof(val), 1)
} else if (access_process_vm(child, addr, &val, sizeof(val),
FOLL_FORCE | FOLL_WRITE)
!= sizeof(val))
return -EIO;
return 0;
@@ -543,7 +544,8 @@ ia64_sync_user_rbs (struct task_struct *child, struct switch_stack *sw,
ret = ia64_peek(child, sw, user_rbs_end, addr, &val);
if (ret < 0)
return ret;
if (access_process_vm(child, addr, &val, sizeof(val), 1)
if (access_process_vm(child, addr, &val, sizeof(val),
FOLL_FORCE | FOLL_WRITE)
!= sizeof(val))
return -EIO;
}
@@ -559,7 +561,8 @@ ia64_sync_kernel_rbs (struct task_struct *child, struct switch_stack *sw,
/* now copy word for word from user rbs to kernel rbs: */
for (addr = user_rbs_start; addr < user_rbs_end; addr += 8) {
if (access_process_vm(child, addr, &val, sizeof(val), 0)
if (access_process_vm(child, addr, &val, sizeof(val),
FOLL_FORCE)
!= sizeof(val))
return -EIO;
@@ -1156,7 +1159,8 @@ arch_ptrace (struct task_struct *child, long request,
case PTRACE_PEEKTEXT:
case PTRACE_PEEKDATA:
/* read word at location addr */
if (access_process_vm(child, addr, &data, sizeof(data), 0)
if (access_process_vm(child, addr, &data, sizeof(data),
FOLL_FORCE)
!= sizeof(data))
return -EIO;
/* ensure return value is not mistaken for error code */