[PATCH -mm 13/43] powerpc ptrace special regs
From: Roland McGrath <hidden>
Date: 2007-12-20 12:00:31
Also in:
linux-arch, lkml
Subsystem:
linux for powerpc (32-bit and 64-bit), ptrace support, the rest · Maintainers:
Madhavan Srinivasan, Oleg Nesterov, Linus Torvalds
This isolates the ptrace code for the special-case registers msr and trap from the ptrace-layout dispatch code. This should inline away completely. It cleanly separates the low-level machine magic that has to be done for deep reasons, from the superficial details of the ptrace interface. Signed-off-by: Roland McGrath <redacted> --- arch/powerpc/kernel/ptrace.c | 45 ++++++++++++++++++++++++++++-------------- 1 files changed, 30 insertions(+), 15 deletions(-)
diff --git a/arch/powerpc/kernel/ptrace.c b/arch/powerpc/kernel/ptrace.c
index 8c25b00..4edc118 100644
--- a/arch/powerpc/kernel/ptrace.c
+++ b/arch/powerpc/kernel/ptrace.c@@ -60,20 +60,38 @@ #define PT_MAX_PUT_REG PT_CCR #endif +static unsigned long get_user_msr(struct task_struct *task) +{ + return task->thread.regs->msr | task->thread.fpexc_mode; +} + +static int set_user_msr(struct task_struct *task, unsigned long msr) +{ + task->thread.regs->msr &= ~MSR_DEBUGCHANGE; + task->thread.regs->msr |= msr & MSR_DEBUGCHANGE; + return 0; +} + +/* + * We prevent mucking around with the reserved area of trap + * which are used internally by the kernel. + */ +static int set_user_trap(struct task_struct *task, unsigned long trap) +{ + task->thread.regs->trap = trap & 0xfff0; + return 0; +} + /* * Get contents of register REGNO in task TASK. */ unsigned long ptrace_get_reg(struct task_struct *task, int regno) { - unsigned long tmp = 0; - if (task->thread.regs == NULL) return -EIO; - if (regno == PT_MSR) { - tmp = ((unsigned long *)task->thread.regs)[PT_MSR]; - return tmp | task->thread.fpexc_mode; - } + if (regno == PT_MSR) + return get_user_msr(task); if (regno < (sizeof(struct pt_regs) / sizeof(unsigned long))) return ((unsigned long *)task->thread.regs)[regno];
@@ -89,15 +107,12 @@ int ptrace_put_reg(struct task_struct *task, int regno, unsigned long data) if (task->thread.regs == NULL) return -EIO; - if (regno <= PT_MAX_PUT_REG || regno == PT_TRAP) { - if (regno == PT_MSR) - data = (data & MSR_DEBUGCHANGE) - | (task->thread.regs->msr & ~MSR_DEBUGCHANGE); - /* We prevent mucking around with the reserved area of trap - * which are used internally by the kernel - */ - if (regno == PT_TRAP) - data &= 0xfff0; + if (regno == PT_MSR) + return set_user_msr(task, data); + if (regno == PT_TRAP) + return set_user_trap(task, data); + + if (regno <= PT_MAX_PUT_REG) { ((unsigned long *)task->thread.regs)[regno] = data; return 0; }
--
1.5.3.6