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author | David Daney <ddaney@avtrex.com> | 2008-09-23 00:11:26 -0700 |
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committer | Ralf Baechle <ralf@linux-mips.org> | 2008-10-11 16:18:57 +0100 |
commit | 0926bf953ee79b8f139741b442e5a18520f81705 (patch) | |
tree | 5e2cbdb2060ec9324866e6a072d1d7666849445c /arch/mips/kernel/ptrace.c | |
parent | 2c708cbaa6031b73be6b992adb3ec1811f91cdb1 (diff) | |
download | linux-0926bf953ee79b8f139741b442e5a18520f81705.tar.gz linux-0926bf953ee79b8f139741b442e5a18520f81705.tar.bz2 linux-0926bf953ee79b8f139741b442e5a18520f81705.zip |
MIPS: Ptrace support for HARDWARE_WATCHPOINTS
This is the final part of the watch register patch. Here we hook up
ptrace so that the user space debugger (gdb), can set and read the
registers.
Signed-off-by: David Daney <ddaney@avtrex.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Diffstat (limited to 'arch/mips/kernel/ptrace.c')
-rw-r--r-- | arch/mips/kernel/ptrace.c | 100 |
1 files changed, 99 insertions, 1 deletions
diff --git a/arch/mips/kernel/ptrace.c b/arch/mips/kernel/ptrace.c index 96ffc9c6d194..054861ccb4dd 100644 --- a/arch/mips/kernel/ptrace.c +++ b/arch/mips/kernel/ptrace.c @@ -46,7 +46,8 @@ */ void ptrace_disable(struct task_struct *child) { - /* Nothing to do.. */ + /* Don't load the watchpoint registers for the ex-child. */ + clear_tsk_thread_flag(child, TIF_LOAD_WATCH); } /* @@ -167,6 +168,93 @@ int ptrace_setfpregs(struct task_struct *child, __u32 __user *data) return 0; } +int ptrace_get_watch_regs(struct task_struct *child, + struct pt_watch_regs __user *addr) +{ + enum pt_watch_style style; + int i; + + if (!cpu_has_watch || current_cpu_data.watch_reg_use_cnt == 0) + return -EIO; + if (!access_ok(VERIFY_WRITE, addr, sizeof(struct pt_watch_regs))) + return -EIO; + +#ifdef CONFIG_32BIT + style = pt_watch_style_mips32; +#define WATCH_STYLE mips32 +#else + style = pt_watch_style_mips64; +#define WATCH_STYLE mips64 +#endif + + __put_user(style, &addr->style); + __put_user(current_cpu_data.watch_reg_use_cnt, + &addr->WATCH_STYLE.num_valid); + for (i = 0; i < current_cpu_data.watch_reg_use_cnt; i++) { + __put_user(child->thread.watch.mips3264.watchlo[i], + &addr->WATCH_STYLE.watchlo[i]); + __put_user(child->thread.watch.mips3264.watchhi[i] & 0xfff, + &addr->WATCH_STYLE.watchhi[i]); + __put_user(current_cpu_data.watch_reg_masks[i], + &addr->WATCH_STYLE.watch_masks[i]); + } + for (; i < 8; i++) { + __put_user(0, &addr->WATCH_STYLE.watchlo[i]); + __put_user(0, &addr->WATCH_STYLE.watchhi[i]); + __put_user(0, &addr->WATCH_STYLE.watch_masks[i]); + } + + return 0; +} + +int ptrace_set_watch_regs(struct task_struct *child, + struct pt_watch_regs __user *addr) +{ + int i; + int watch_active = 0; + unsigned long lt[NUM_WATCH_REGS]; + u16 ht[NUM_WATCH_REGS]; + + if (!cpu_has_watch || current_cpu_data.watch_reg_use_cnt == 0) + return -EIO; + if (!access_ok(VERIFY_READ, addr, sizeof(struct pt_watch_regs))) + return -EIO; + /* Check the values. */ + for (i = 0; i < current_cpu_data.watch_reg_use_cnt; i++) { + __get_user(lt[i], &addr->WATCH_STYLE.watchlo[i]); +#ifdef CONFIG_32BIT + if (lt[i] & __UA_LIMIT) + return -EINVAL; +#else + if (test_tsk_thread_flag(child, TIF_32BIT_ADDR)) { + if (lt[i] & 0xffffffff80000000UL) + return -EINVAL; + } else { + if (lt[i] & __UA_LIMIT) + return -EINVAL; + } +#endif + __get_user(ht[i], &addr->WATCH_STYLE.watchhi[i]); + if (ht[i] & ~0xff8) + return -EINVAL; + } + /* Install them. */ + for (i = 0; i < current_cpu_data.watch_reg_use_cnt; i++) { + if (lt[i] & 7) + watch_active = 1; + child->thread.watch.mips3264.watchlo[i] = lt[i]; + /* Set the G bit. */ + child->thread.watch.mips3264.watchhi[i] = ht[i]; + } + + if (watch_active) + set_tsk_thread_flag(child, TIF_LOAD_WATCH); + else + clear_tsk_thread_flag(child, TIF_LOAD_WATCH); + + return 0; +} + long arch_ptrace(struct task_struct *child, long request, long addr, long data) { int ret; @@ -440,6 +528,16 @@ long arch_ptrace(struct task_struct *child, long request, long addr, long data) (unsigned long __user *) data); break; + case PTRACE_GET_WATCH_REGS: + ret = ptrace_get_watch_regs(child, + (struct pt_watch_regs __user *) addr); + break; + + case PTRACE_SET_WATCH_REGS: + ret = ptrace_set_watch_regs(child, + (struct pt_watch_regs __user *) addr); + break; + default: ret = ptrace_request(child, request, addr, data); break; |