4.16-stable review patch. If anyone has any objections, please let me know.
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From: Mark Rutland mark.rutland@arm.com
[ Upstream commit 59275a0c037ed6fabd6354730f1e3104264ab719 ]
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 Signed-off-by: Sasha Levin alexander.levin@microsoft.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- arch/arm64/kernel/ptrace.c | 6 ------ 1 file changed, 6 deletions(-)
--- a/arch/arm64/kernel/ptrace.c +++ b/arch/arm64/kernel/ptrace.c @@ -1458,9 +1458,7 @@ static int compat_ptrace_gethbpregs(stru { int ret; u32 kdata; - mm_segment_t old_fs = get_fs();
- set_fs(KERNEL_DS); /* Watchpoint */ if (num < 0) { ret = compat_ptrace_hbp_get(NT_ARM_HW_WATCH, tsk, num, &kdata); @@ -1471,7 +1469,6 @@ static int compat_ptrace_gethbpregs(stru } else { ret = compat_ptrace_hbp_get(NT_ARM_HW_BREAK, tsk, num, &kdata); } - set_fs(old_fs);
if (!ret) ret = put_user(kdata, data); @@ -1484,7 +1481,6 @@ static int compat_ptrace_sethbpregs(stru { int ret; u32 kdata = 0; - mm_segment_t old_fs = get_fs();
if (num == 0) return 0; @@ -1493,12 +1489,10 @@ static int compat_ptrace_sethbpregs(stru if (ret) return ret;
- set_fs(KERNEL_DS); if (num < 0) ret = compat_ptrace_hbp_set(NT_ARM_HW_WATCH, tsk, num, &kdata); else ret = compat_ptrace_hbp_set(NT_ARM_HW_BREAK, tsk, num, &kdata); - set_fs(old_fs);
return ret; }