diff options
Diffstat (limited to 'arch/x86/kernel/hw_breakpoint.c')
| -rw-r--r-- | arch/x86/kernel/hw_breakpoint.c | 65 |
1 files changed, 34 insertions, 31 deletions
diff --git a/arch/x86/kernel/hw_breakpoint.c b/arch/x86/kernel/hw_breakpoint.c index a474ec37c32..5f9cf20cdb6 100644 --- a/arch/x86/kernel/hw_breakpoint.c +++ b/arch/x86/kernel/hw_breakpoint.c @@ -32,13 +32,11 @@ #include <linux/irqflags.h> #include <linux/notifier.h> #include <linux/kallsyms.h> -#include <linux/kprobes.h> #include <linux/percpu.h> #include <linux/kdebug.h> #include <linux/kernel.h> #include <linux/module.h> #include <linux/sched.h> -#include <linux/init.h> #include <linux/smp.h> #include <asm/hw_breakpoint.h> @@ -122,7 +120,7 @@ int arch_install_hw_breakpoint(struct perf_event *bp) return -EBUSY; set_debugreg(info->address, i); - __get_cpu_var(cpu_debugreg[i]) = info->address; + __this_cpu_write(cpu_debugreg[i], info->address); dr7 = &__get_cpu_var(cpu_dr7); *dr7 |= encode_dr7(i, info->len, info->type); @@ -206,11 +204,27 @@ int arch_check_bp_in_kernelspace(struct perf_event *bp) int arch_bp_generic_fields(int x86_len, int x86_type, int *gen_len, int *gen_type) { - /* Len */ - switch (x86_len) { - case X86_BREAKPOINT_LEN_X: + /* Type */ + switch (x86_type) { + case X86_BREAKPOINT_EXECUTE: + if (x86_len != X86_BREAKPOINT_LEN_X) + return -EINVAL; + + *gen_type = HW_BREAKPOINT_X; *gen_len = sizeof(long); + return 0; + case X86_BREAKPOINT_WRITE: + *gen_type = HW_BREAKPOINT_W; break; + case X86_BREAKPOINT_RW: + *gen_type = HW_BREAKPOINT_W | HW_BREAKPOINT_R; + break; + default: + return -EINVAL; + } + + /* Len */ + switch (x86_len) { case X86_BREAKPOINT_LEN_1: *gen_len = HW_BREAKPOINT_LEN_1; break; @@ -229,21 +243,6 @@ int arch_bp_generic_fields(int x86_len, int x86_type, return -EINVAL; } - /* Type */ - switch (x86_type) { - case X86_BREAKPOINT_EXECUTE: - *gen_type = HW_BREAKPOINT_X; - break; - case X86_BREAKPOINT_WRITE: - *gen_type = HW_BREAKPOINT_W; - break; - case X86_BREAKPOINT_RW: - *gen_type = HW_BREAKPOINT_W | HW_BREAKPOINT_R; - break; - default: - return -EINVAL; - } - return 0; } @@ -316,9 +315,6 @@ int arch_validate_hwbkpt_settings(struct perf_event *bp) ret = -EINVAL; switch (info->len) { - case X86_BREAKPOINT_LEN_X: - align = sizeof(long) -1; - break; case X86_BREAKPOINT_LEN_1: align = 0; break; @@ -395,16 +391,19 @@ void flush_ptrace_hw_breakpoint(struct task_struct *tsk) unregister_hw_breakpoint(t->ptrace_bps[i]); t->ptrace_bps[i] = NULL; } + + t->debugreg6 = 0; + t->ptrace_dr7 = 0; } void hw_breakpoint_restore(void) { - set_debugreg(__get_cpu_var(cpu_debugreg[0]), 0); - set_debugreg(__get_cpu_var(cpu_debugreg[1]), 1); - set_debugreg(__get_cpu_var(cpu_debugreg[2]), 2); - set_debugreg(__get_cpu_var(cpu_debugreg[3]), 3); + set_debugreg(__this_cpu_read(cpu_debugreg[0]), 0); + set_debugreg(__this_cpu_read(cpu_debugreg[1]), 1); + set_debugreg(__this_cpu_read(cpu_debugreg[2]), 2); + set_debugreg(__this_cpu_read(cpu_debugreg[3]), 3); set_debugreg(current->thread.debugreg6, 6); - set_debugreg(__get_cpu_var(cpu_dr7), 7); + set_debugreg(__this_cpu_read(cpu_dr7), 7); } EXPORT_SYMBOL_GPL(hw_breakpoint_restore); @@ -424,7 +423,7 @@ EXPORT_SYMBOL_GPL(hw_breakpoint_restore); * NOTIFY_STOP returned for all other cases * */ -static int __kprobes hw_breakpoint_handler(struct die_args *args) +static int hw_breakpoint_handler(struct die_args *args) { int i, cpu, rc = NOTIFY_STOP; struct perf_event *bp; @@ -435,6 +434,10 @@ static int __kprobes hw_breakpoint_handler(struct die_args *args) dr6_p = (unsigned long *)ERR_PTR(args->err); dr6 = *dr6_p; + /* If it's a single step, TRAP bits are random */ + if (dr6 & DR_STEP) + return NOTIFY_DONE; + /* Do an early return if no trap bits are set in DR6 */ if ((dr6 & DR_TRAP_BITS) == 0) return NOTIFY_DONE; @@ -507,7 +510,7 @@ static int __kprobes hw_breakpoint_handler(struct die_args *args) /* * Handle debug exception notifications. */ -int __kprobes hw_breakpoint_exceptions_notify( +int hw_breakpoint_exceptions_notify( struct notifier_block *unused, unsigned long val, void *data) { if (val != DIE_DEBUG) |