From mboxrd@z Thu Jan 1 00:00:00 1970 From: mark.rutland@arm.com (Mark Rutland) Date: Tue, 24 Apr 2018 13:11:22 +0100 Subject: [PATCH] arm64: ptrace: remove addr_limit manipulation Message-ID: <20180424121122.30294-1-mark.rutland@arm.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org 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. Signed-off-by: Mark Rutland Cc: Will Deacon --- arch/arm64/kernel/ptrace.c | 6 ------ 1 file changed, 6 deletions(-) diff --git a/arch/arm64/kernel/ptrace.c b/arch/arm64/kernel/ptrace.c index 71d99af24ef2..7a832ce6552f 100644 --- a/arch/arm64/kernel/ptrace.c +++ b/arch/arm64/kernel/ptrace.c @@ -1458,9 +1458,7 @@ static int compat_ptrace_gethbpregs(struct task_struct *tsk, compat_long_t num, { 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(struct task_struct *tsk, compat_long_t num, } 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(struct task_struct *tsk, compat_long_t num, { 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(struct task_struct *tsk, compat_long_t num, 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; } -- 2.11.0