From: David Daney Date: Tue, 23 Sep 2008 07:11:26 +0000 (-0700) Subject: MIPS: Ptrace support for HARDWARE_WATCHPOINTS X-Git-Tag: v2.6.28-rc1~719^2~2 X-Git-Url: http://pilppa.com/gitweb/?a=commitdiff_plain;h=0926bf953ee79b8f139741b442e5a18520f81705;p=linux-2.6-omap-h63xx.git 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 Signed-off-by: Ralf Baechle --- diff --git a/arch/mips/include/asm/ptrace.h b/arch/mips/include/asm/ptrace.h index c00cca24dae..cd5e8a47812 100644 --- a/arch/mips/include/asm/ptrace.h +++ b/arch/mips/include/asm/ptrace.h @@ -74,11 +74,57 @@ struct pt_regs { #define PTRACE_POKEDATA_3264 0xc3 #define PTRACE_GET_THREAD_AREA_3264 0xc4 +/* Read and write watchpoint registers. */ +enum pt_watch_style { + pt_watch_style_mips32, + pt_watch_style_mips64 +}; +struct mips32_watch_regs { + uint32_t watchlo[8]; + /* Lower 16 bits of watchhi. */ + uint16_t watchhi[8]; + /* Valid mask and I R W bits. + * bit 0 -- 1 if W bit is usable. + * bit 1 -- 1 if R bit is usable. + * bit 2 -- 1 if I bit is usable. + * bits 3 - 11 -- Valid watchhi mask bits. + */ + uint16_t watch_masks[8]; + /* The number of valid watch register pairs. */ + uint32_t num_valid; +} __attribute__((aligned(8))); + +struct mips64_watch_regs { + uint64_t watchlo[8]; + uint16_t watchhi[8]; + uint16_t watch_masks[8]; + uint32_t num_valid; +} __attribute__((aligned(8))); + +struct pt_watch_regs { + enum pt_watch_style style; + union { + struct mips32_watch_regs mips32; + struct mips32_watch_regs mips64; + }; +}; + +#define PTRACE_GET_WATCH_REGS 0xd0 +#define PTRACE_SET_WATCH_REGS 0xd1 + #ifdef __KERNEL__ +#include #include #include +struct task_struct; + +extern int ptrace_get_watch_regs(struct task_struct *child, + struct pt_watch_regs __user *addr); +extern int ptrace_set_watch_regs(struct task_struct *child, + struct pt_watch_regs __user *addr); + /* * Does the process account for user or for system time? */ diff --git a/arch/mips/kernel/ptrace.c b/arch/mips/kernel/ptrace.c index 96ffc9c6d19..054861ccb4d 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; diff --git a/arch/mips/kernel/ptrace32.c b/arch/mips/kernel/ptrace32.c index cac56a8c867..e45105e3ef0 100644 --- a/arch/mips/kernel/ptrace32.c +++ b/arch/mips/kernel/ptrace32.c @@ -387,6 +387,16 @@ long compat_arch_ptrace(struct task_struct *child, compat_long_t request, (unsigned long __user *) (unsigned long) data); break; + case PTRACE_GET_WATCH_REGS: + ret = ptrace_get_watch_regs(child, + (struct pt_watch_regs __user *) (unsigned long) addr); + break; + + case PTRACE_SET_WATCH_REGS: + ret = ptrace_set_watch_regs(child, + (struct pt_watch_regs __user *) (unsigned long) addr); + break; + default: ret = ptrace_request(child, request, addr, data); break;