From e6ec885f5f4ce93f5fb446c52131ac159e7e63f6 Mon Sep 17 00:00:00 2001 From: Mark Rutland Date: Tue, 24 Apr 2018 13:11:22 +0100 Subject: [PATCH] arm64: ptrace: remove addr_limit manipulation [ 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 Signed-off-by: Mark Rutland Cc: Will Deacon Signed-off-by: Will Deacon Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- 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 9cbb6123208f..85e80a473130 100644 --- a/arch/arm64/kernel/ptrace.c +++ b/arch/arm64/kernel/ptrace.c @@ -1194,9 +1194,7 @@ 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); @@ -1207,7 +1205,6 @@ 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); @@ -1220,7 +1217,6 @@ 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; @@ -1229,12 +1225,10 @@ 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; } -- 2.20.1