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arm64: ptrace: remove addr_limit manipulation

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We transiently switch to KERNEL_DS in compat_ptrace_gethbpregs() and
compat_ptrace_sethbpregs(), but in either case this is pointless as we
don't perform any uaccess during this window.

let's rip out the redundant addr_limit manipulation.

Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
This commit is contained in:
Mark Rutland
2018-04-24 13:11:22 +01:00
committed by Will Deacon
parent 907e21c15c
commit 59275a0c03
1 changed files with 0 additions and 6 deletions
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6
arch/arm64/kernel/ptrace.c
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@ -1458,9 +1458,7 @@ static int compat_ptrace_gethbpregs(struct task_struct *tsk, compat_long_t num,
{ {
int ret; int ret;
u32 kdata; u32 kdata;
mm_segment_t old_fs = get_fs();
set_fs(KERNEL_DS);
/* Watchpoint */ /* Watchpoint */
if (num < 0) { if (num < 0) {
ret = compat_ptrace_hbp_get(NT_ARM_HW_WATCH, tsk, num, &kdata); ret = compat_ptrace_hbp_get(NT_ARM_HW_WATCH, tsk, num, &kdata);
@ -1471,7 +1469,6 @@ static int compat_ptrace_gethbpregs(struct task_struct *tsk, compat_long_t num,
} else { } else {
ret = compat_ptrace_hbp_get(NT_ARM_HW_BREAK, tsk, num, &kdata); ret = compat_ptrace_hbp_get(NT_ARM_HW_BREAK, tsk, num, &kdata);
} }
set_fs(old_fs);
if (!ret) if (!ret)
ret = put_user(kdata, data); ret = put_user(kdata, data);
@ -1484,7 +1481,6 @@ static int compat_ptrace_sethbpregs(struct task_struct *tsk, compat_long_t num,
{ {
int ret; int ret;
u32 kdata = 0; u32 kdata = 0;
mm_segment_t old_fs = get_fs();
if (num == 0) if (num == 0)
return 0; return 0;
@ -1493,12 +1489,10 @@ static int compat_ptrace_sethbpregs(struct task_struct *tsk, compat_long_t num,
if (ret) if (ret)
return ret; return ret;
set_fs(KERNEL_DS);
if (num < 0) if (num < 0)
ret = compat_ptrace_hbp_set(NT_ARM_HW_WATCH, tsk, num, &kdata); ret = compat_ptrace_hbp_set(NT_ARM_HW_WATCH, tsk, num, &kdata);
else else
ret = compat_ptrace_hbp_set(NT_ARM_HW_BREAK, tsk, num, &kdata); ret = compat_ptrace_hbp_set(NT_ARM_HW_BREAK, tsk, num, &kdata);
set_fs(old_fs);
return ret; return ret;
} }