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authorLorenzo Stoakes <lstoakes@gmail.com>2016-10-13 01:20:20 +0100
committerLinus Torvalds <torvalds@linux-foundation.org>2016-10-19 08:31:25 -0700
commitf307ab6dcea03f9d8e4d70508fd7d1ca57cfa7f9 (patch)
tree94a96ebae9957cf1252231a69f8904796aa2563e /arch/x86
parent6347e8d5bcce33fc36e651901efefbe2c93a43ef (diff)
downloadlinux-f307ab6dcea03f9d8e4d70508fd7d1ca57cfa7f9.tar.bz2
mm: replace access_process_vm() write parameter with gup_flags
This removes the 'write' argument from access_process_vm() and replaces it with 'gup_flags' as use of this function previously silently implied FOLL_FORCE, whereas after this patch callers explicitly pass this flag. We make this explicit as use of FOLL_FORCE can result in surprising behaviour (and hence bugs) within the mm subsystem. Signed-off-by: Lorenzo Stoakes <lstoakes@gmail.com> Acked-by: Jesper Nilsson <jesper.nilsson@axis.com> Acked-by: Michal Hocko <mhocko@suse.com> Acked-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'arch/x86')
-rw-r--r--arch/x86/kernel/step.c3
-rw-r--r--arch/x86/um/ptrace_32.c3
-rw-r--r--arch/x86/um/ptrace_64.c3
3 files changed, 6 insertions, 3 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/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);