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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/x86
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/x86')
-rw-r--r--arch/x86/kernel/step.c3
-rw-r--r--arch/x86/mm/gup.c2
-rw-r--r--arch/x86/mm/mpx.c5
-rw-r--r--arch/x86/um/ptrace_32.c3
-rw-r--r--arch/x86/um/ptrace_64.c3
5 files changed, 9 insertions, 7 deletions
diff --git a/arch/x86/kernel/step.c b/arch/x86/kernel/step.c
index c9a073866ca7..a23ce84a3f6c 100644
--- a/arch/x86/kernel/step.c
+++ b/arch/x86/kernel/step.c
@@ -57,7 +57,8 @@ static int is_setting_trap_flag(struct task_struct *child, struct pt_regs *regs)
unsigned char opcode[15];
unsigned long addr = convert_ip_to_linear(child, regs);
- copied = access_process_vm(child, addr, opcode, sizeof(opcode), 0);
+ copied = access_process_vm(child, addr, opcode, sizeof(opcode),
+ FOLL_FORCE);
for (i = 0; i < copied; i++) {
switch (opcode[i]) {
/* popf and iret */
diff --git a/arch/x86/mm/gup.c b/arch/x86/mm/gup.c
index b8b6a60b32cf..0d4fb3ebbbac 100644
--- a/arch/x86/mm/gup.c
+++ b/arch/x86/mm/gup.c
@@ -435,7 +435,7 @@ slow_irqon:
ret = get_user_pages_unlocked(start,
(end - start) >> PAGE_SHIFT,
- write, 0, pages);
+ pages, write ? FOLL_WRITE : 0);
/* Have to be a bit careful with return values */
if (nr > 0) {
diff --git a/arch/x86/mm/mpx.c b/arch/x86/mm/mpx.c
index 80476878eb4c..e4f800999b32 100644
--- a/arch/x86/mm/mpx.c
+++ b/arch/x86/mm/mpx.c
@@ -544,10 +544,9 @@ static int mpx_resolve_fault(long __user *addr, int write)
{
long gup_ret;
int nr_pages = 1;
- int force = 0;
- gup_ret = get_user_pages((unsigned long)addr, nr_pages, write,
- force, NULL, NULL);
+ gup_ret = get_user_pages((unsigned long)addr, nr_pages,
+ write ? FOLL_WRITE : 0, NULL, NULL);
/*
* get_user_pages() returns number of pages gotten.
* 0 means we failed to fault in and get anything,
diff --git a/arch/x86/um/ptrace_32.c b/arch/x86/um/ptrace_32.c
index 5766ead6fdb9..60a5a5a85505 100644
--- a/arch/x86/um/ptrace_32.c
+++ b/arch/x86/um/ptrace_32.c
@@ -36,7 +36,8 @@ int is_syscall(unsigned long addr)
* slow, but that doesn't matter, since it will be called only
* in case of singlestepping, if copy_from_user failed.
*/
- n = access_process_vm(current, addr, &instr, sizeof(instr), 0);
+ n = access_process_vm(current, addr, &instr, sizeof(instr),
+ FOLL_FORCE);
if (n != sizeof(instr)) {
printk(KERN_ERR "is_syscall : failed to read "
"instruction from 0x%lx\n", addr);
diff --git a/arch/x86/um/ptrace_64.c b/arch/x86/um/ptrace_64.c
index 0b5c184dd5b3..e30202b1716e 100644
--- a/arch/x86/um/ptrace_64.c
+++ b/arch/x86/um/ptrace_64.c
@@ -212,7 +212,8 @@ int is_syscall(unsigned long addr)
* slow, but that doesn't matter, since it will be called only
* in case of singlestepping, if copy_from_user failed.
*/
- n = access_process_vm(current, addr, &instr, sizeof(instr), 0);
+ n = access_process_vm(current, addr, &instr, sizeof(instr),
+ FOLL_FORCE);
if (n != sizeof(instr)) {
printk("is_syscall : failed to read instruction from "
"0x%lx\n", addr);