diff options
author | David S. Miller <davem@davemloft.net> | 2010-05-18 23:01:55 -0700 |
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committer | David S. Miller <davem@davemloft.net> | 2010-05-18 23:01:55 -0700 |
commit | 2ec8c6bb5d8f3a62a79f463525054bae1e3d4487 (patch) | |
tree | fa7f8400ac685fb52e96f64997c7c682fc2aa021 /arch/x86/kernel/step.c | |
parent | 7b39f90fabcf9e2af0cd79d0a60440d821e22b56 (diff) | |
parent | 537b60d17894b7c19a6060feae40299d7109d6e7 (diff) |
Merge branch 'master' of /home/davem/src/GIT/linux-2.6/
Conflicts:
include/linux/mod_devicetable.h
scripts/mod/file2alias.c
Diffstat (limited to 'arch/x86/kernel/step.c')
-rw-r--r-- | arch/x86/kernel/step.c | 46 |
1 files changed, 17 insertions, 29 deletions
diff --git a/arch/x86/kernel/step.c b/arch/x86/kernel/step.c index 3149032ff107..58de45ee08b6 100644 --- a/arch/x86/kernel/step.c +++ b/arch/x86/kernel/step.c @@ -158,22 +158,6 @@ static int enable_single_step(struct task_struct *child) } /* - * Install this value in MSR_IA32_DEBUGCTLMSR whenever child is running. - */ -static void write_debugctlmsr(struct task_struct *child, unsigned long val) -{ - if (child->thread.debugctlmsr == val) - return; - - child->thread.debugctlmsr = val; - - if (child != current) - return; - - update_debugctlmsr(val); -} - -/* * Enable single or block step. */ static void enable_step(struct task_struct *child, bool block) @@ -186,15 +170,17 @@ static void enable_step(struct task_struct *child, bool block) * that uses user-mode single stepping itself. */ if (enable_single_step(child) && block) { - set_tsk_thread_flag(child, TIF_DEBUGCTLMSR); - write_debugctlmsr(child, - child->thread.debugctlmsr | DEBUGCTLMSR_BTF); - } else { - write_debugctlmsr(child, - child->thread.debugctlmsr & ~DEBUGCTLMSR_BTF); - - if (!child->thread.debugctlmsr) - clear_tsk_thread_flag(child, TIF_DEBUGCTLMSR); + unsigned long debugctl = get_debugctlmsr(); + + debugctl |= DEBUGCTLMSR_BTF; + update_debugctlmsr(debugctl); + set_tsk_thread_flag(child, TIF_BLOCKSTEP); + } else if (test_tsk_thread_flag(child, TIF_BLOCKSTEP)) { + unsigned long debugctl = get_debugctlmsr(); + + debugctl &= ~DEBUGCTLMSR_BTF; + update_debugctlmsr(debugctl); + clear_tsk_thread_flag(child, TIF_BLOCKSTEP); } } @@ -213,11 +199,13 @@ void user_disable_single_step(struct task_struct *child) /* * Make sure block stepping (BTF) is disabled. */ - write_debugctlmsr(child, - child->thread.debugctlmsr & ~DEBUGCTLMSR_BTF); + if (test_tsk_thread_flag(child, TIF_BLOCKSTEP)) { + unsigned long debugctl = get_debugctlmsr(); - if (!child->thread.debugctlmsr) - clear_tsk_thread_flag(child, TIF_DEBUGCTLMSR); + debugctl &= ~DEBUGCTLMSR_BTF; + update_debugctlmsr(debugctl); + clear_tsk_thread_flag(child, TIF_BLOCKSTEP); + } /* Always clear TIF_SINGLESTEP... */ clear_tsk_thread_flag(child, TIF_SINGLESTEP); |