From fd9648dff6f9797ecc509bcd181706a274dc074d Mon Sep 17 00:00:00 2001 From: Anton Blanchard Date: Sat, 10 Sep 2005 16:01:11 +1000 Subject: [PATCH] [PATCH] ppc64: Add ptrace data breakpoint support Add hardware data breakpoint support. Signed-off-by: Anton Blanchard Signed-off-by: Paul Mackerras --- arch/ppc64/kernel/process.c | 34 ++++++++++++++++++++++++++++++ arch/ppc64/kernel/ptrace.c | 13 ++++++++++++ arch/ppc64/kernel/ptrace32.c | 13 ++++++++++++ arch/ppc64/kernel/ras.c | 2 -- arch/ppc64/kernel/signal.c | 9 ++++++++ arch/ppc64/kernel/signal32.c | 8 +++++++ arch/ppc64/mm/fault.c | 31 +++++++++++++++++++++------ arch/ppc64/xmon/privinst.h | 1 - arch/ppc64/xmon/xmon.c | 20 ++++-------------- include/asm-ppc64/hvcall.h | 6 ++++++ include/asm-ppc64/plpar_wrappers.h | 9 ++++++++ include/asm-ppc64/processor.h | 1 + include/asm-ppc64/ptrace-common.h | 20 ++++++++++++++++++ include/asm-ppc64/system.h | 3 +++ 14 files changed, 145 insertions(+), 25 deletions(-) diff --git a/arch/ppc64/kernel/process.c b/arch/ppc64/kernel/process.c index 7a7e027653..887005358e 100644 --- a/arch/ppc64/kernel/process.c +++ b/arch/ppc64/kernel/process.c @@ -54,6 +54,7 @@ #include #include #include +#include #ifndef CONFIG_SMP struct task_struct *last_task_used_math = NULL; @@ -163,7 +164,30 @@ int dump_task_altivec(struct pt_regs *regs, elf_vrregset_t *vrregs) #endif /* CONFIG_ALTIVEC */ +static void set_dabr_spr(unsigned long val) +{ + mtspr(SPRN_DABR, val); +} + +int set_dabr(unsigned long dabr) +{ + int ret = 0; + + if (firmware_has_feature(FW_FEATURE_XDABR)) { + /* We want to catch accesses from kernel and userspace */ + unsigned long flags = H_DABRX_KERNEL|H_DABRX_USER; + ret = plpar_set_xdabr(dabr, flags); + } else if (firmware_has_feature(FW_FEATURE_DABR)) { + ret = plpar_set_dabr(dabr); + } else { + set_dabr_spr(dabr); + } + + return ret; +} + DEFINE_PER_CPU(struct cpu_usage, cpu_usage_array); +static DEFINE_PER_CPU(unsigned long, current_dabr); struct task_struct *__switch_to(struct task_struct *prev, struct task_struct *new) @@ -198,6 +222,11 @@ struct task_struct *__switch_to(struct task_struct *prev, new->thread.regs->msr |= MSR_VEC; #endif /* CONFIG_ALTIVEC */ + if (unlikely(__get_cpu_var(current_dabr) != new->thread.dabr)) { + set_dabr(new->thread.dabr); + __get_cpu_var(current_dabr) = new->thread.dabr; + } + flush_tlb_pending(); new_thread = &new->thread; @@ -334,6 +363,11 @@ void flush_thread(void) last_task_used_altivec = NULL; #endif /* CONFIG_ALTIVEC */ #endif /* CONFIG_SMP */ + + if (current->thread.dabr) { + current->thread.dabr = 0; + set_dabr(0); + } } void diff --git a/arch/ppc64/kernel/ptrace.c b/arch/ppc64/kernel/ptrace.c index bf7116d4c4..85ed3188a9 100644 --- a/arch/ppc64/kernel/ptrace.c +++ b/arch/ppc64/kernel/ptrace.c @@ -207,6 +207,19 @@ int sys_ptrace(long request, long pid, long addr, long data) break; } + case PTRACE_GET_DEBUGREG: { + ret = -EINVAL; + /* We only support one DABR and no IABRS at the moment */ + if (addr > 0) + break; + ret = put_user(child->thread.dabr, + (unsigned long __user *)data); + break; + } + + case PTRACE_SET_DEBUGREG: + ret = ptrace_set_debugreg(child, addr, data); + case PTRACE_DETACH: ret = ptrace_detach(child, data); break; diff --git a/arch/ppc64/kernel/ptrace32.c b/arch/ppc64/kernel/ptrace32.c index cbb1e0fb88..fb8c22d608 100644 --- a/arch/ppc64/kernel/ptrace32.c +++ b/arch/ppc64/kernel/ptrace32.c @@ -338,6 +338,19 @@ int sys32_ptrace(long request, long pid, unsigned long addr, unsigned long data) break; } + case PTRACE_GET_DEBUGREG: { + ret = -EINVAL; + /* We only support one DABR and no IABRS at the moment */ + if (addr > 0) + break; + ret = put_user(child->thread.dabr, (u32 __user *)data); + break; + } + + case PTRACE_SET_DEBUGREG: + ret = ptrace_set_debugreg(child, addr, data); + break; + case PTRACE_DETACH: ret = ptrace_detach(child, data); break; diff --git a/arch/ppc64/kernel/ras.c b/arch/ppc64/kernel/ras.c index 3c00f7bfc1..41b97dc9cc 100644 --- a/arch/ppc64/kernel/ras.c +++ b/arch/ppc64/kernel/ras.c @@ -59,8 +59,6 @@ char mce_data_buf[RTAS_ERROR_LOG_MAX] /* This is true if we are using the firmware NMI handler (typically LPAR) */ extern int fwnmi_active; -extern void _exception(int signr, struct pt_regs *regs, int code, unsigned long addr); - static int ras_get_sensor_state_token; static int ras_check_exception_token; diff --git a/arch/ppc64/kernel/signal.c b/arch/ppc64/kernel/signal.c index 49a79a55c3..347112cca3 100644 --- a/arch/ppc64/kernel/signal.c +++ b/arch/ppc64/kernel/signal.c @@ -550,6 +550,15 @@ int do_signal(sigset_t *oldset, struct pt_regs *regs) /* Whee! Actually deliver the signal. */ if (TRAP(regs) == 0x0C00) syscall_restart(regs, &ka); + + /* + * Reenable the DABR before delivering the signal to + * user space. The DABR will have been cleared if it + * triggered inside the kernel. + */ + if (current->thread.dabr) + set_dabr(current->thread.dabr); + return handle_signal(signr, &ka, &info, oldset, regs); } diff --git a/arch/ppc64/kernel/signal32.c b/arch/ppc64/kernel/signal32.c index 46f4d6cc7f..a8b7a5a56b 100644 --- a/arch/ppc64/kernel/signal32.c +++ b/arch/ppc64/kernel/signal32.c @@ -970,6 +970,14 @@ int do_signal32(sigset_t *oldset, struct pt_regs *regs) newsp = regs->gpr[1]; newsp &= ~0xfUL; + /* + * Reenable the DABR before delivering the signal to + * user space. The DABR will have been cleared if it + * triggered inside the kernel. + */ + if (current->thread.dabr) + set_dabr(current->thread.dabr); + /* Whee! Actually deliver the signal. */ if (ka.sa.sa_flags & SA_SIGINFO) ret = handle_rt_signal32(signr, &ka, &info, oldset, regs, newsp); diff --git a/arch/ppc64/mm/fault.c b/arch/ppc64/mm/fault.c index 772f0714a5..7fbc68bbb7 100644 --- a/arch/ppc64/mm/fault.c +++ b/arch/ppc64/mm/fault.c @@ -77,6 +77,28 @@ static int store_updates_sp(struct pt_regs *regs) return 0; } +static void do_dabr(struct pt_regs *regs, unsigned long error_code) +{ + siginfo_t info; + + if (notify_die(DIE_DABR_MATCH, "dabr_match", regs, error_code, + 11, SIGSEGV) == NOTIFY_STOP) + return; + + if (debugger_dabr_match(regs)) + return; + + /* Clear the DABR */ + set_dabr(0); + + /* Deliver the signal to userspace */ + info.si_signo = SIGTRAP; + info.si_errno = 0; + info.si_code = TRAP_HWBKPT; + info.si_addr = (void __user *)regs->nip; + force_sig_info(SIGTRAP, &info, current); +} + /* * The error_code parameter is * - DSISR for a non-SLB data access fault, @@ -111,12 +133,9 @@ int __kprobes do_page_fault(struct pt_regs *regs, unsigned long address, if (!user_mode(regs) && (address >= TASK_SIZE)) return SIGSEGV; - if (error_code & DSISR_DABRMATCH) { - if (notify_die(DIE_DABR_MATCH, "dabr_match", regs, error_code, - 11, SIGSEGV) == NOTIFY_STOP) - return 0; - if (debugger_dabr_match(regs)) - return 0; + if (error_code & DSISR_DABRMATCH) { + do_dabr(regs, error_code); + return 0; } if (in_atomic() || mm == NULL) { diff --git a/arch/ppc64/xmon/privinst.h b/arch/ppc64/xmon/privinst.h index 183c3e4002..02eb40dac0 100644 --- a/arch/ppc64/xmon/privinst.h +++ b/arch/ppc64/xmon/privinst.h @@ -46,7 +46,6 @@ GSETSPR(287, pvr) GSETSPR(1008, hid0) GSETSPR(1009, hid1) GSETSPR(1010, iabr) -GSETSPR(1013, dabr) GSETSPR(1023, pir) static inline void store_inst(void *p) diff --git a/arch/ppc64/xmon/xmon.c b/arch/ppc64/xmon/xmon.c index 45908b10ac..74e63a886a 100644 --- a/arch/ppc64/xmon/xmon.c +++ b/arch/ppc64/xmon/xmon.c @@ -586,6 +586,8 @@ int xmon_dabr_match(struct pt_regs *regs) { if ((regs->msr & (MSR_IR|MSR_PR|MSR_SF)) != (MSR_IR|MSR_SF)) return 0; + if (dabr.enabled == 0) + return 0; xmon_core(regs, 0); return 1; } @@ -628,20 +630,6 @@ int xmon_fault_handler(struct pt_regs *regs) return 0; } -/* On systems with a hypervisor, we can't set the DABR - (data address breakpoint register) directly. */ -static void set_controlled_dabr(unsigned long val) -{ -#ifdef CONFIG_PPC_PSERIES - if (systemcfg->platform == PLATFORM_PSERIES_LPAR) { - int rc = plpar_hcall_norets(H_SET_DABR, val); - if (rc != H_Success) - xmon_printf("Warning: setting DABR failed (%d)\n", rc); - } else -#endif - set_dabr(val); -} - static struct bpt *at_breakpoint(unsigned long pc) { int i; @@ -728,7 +716,7 @@ static void insert_bpts(void) static void insert_cpu_bpts(void) { if (dabr.enabled) - set_controlled_dabr(dabr.address | (dabr.enabled & 7)); + set_dabr(dabr.address | (dabr.enabled & 7)); if (iabr && cpu_has_feature(CPU_FTR_IABR)) set_iabr(iabr->address | (iabr->enabled & (BP_IABR|BP_IABR_TE))); @@ -756,7 +744,7 @@ static void remove_bpts(void) static void remove_cpu_bpts(void) { - set_controlled_dabr(0); + set_dabr(0); if (cpu_has_feature(CPU_FTR_IABR)) set_iabr(0); } diff --git a/include/asm-ppc64/hvcall.h b/include/asm-ppc64/hvcall.h index 4f668a4baf..ab7c3cf248 100644 --- a/include/asm-ppc64/hvcall.h +++ b/include/asm-ppc64/hvcall.h @@ -56,6 +56,11 @@ #define H_PP1 (1UL<<(63-62)) #define H_PP2 (1UL<<(63-63)) +/* DABRX flags */ +#define H_DABRX_HYPERVISOR (1UL<<(63-61)) +#define H_DABRX_KERNEL (1UL<<(63-62)) +#define H_DABRX_USER (1UL<<(63-63)) + /* pSeries hypervisor opcodes */ #define H_REMOVE 0x04 #define H_ENTER 0x08 @@ -101,6 +106,7 @@ #define H_VIO_SIGNAL 0x104 #define H_SEND_CRQ 0x108 #define H_COPY_RDMA 0x110 +#define H_SET_XDABR 0x134 #define H_STUFF_TCE 0x138 #define H_PUT_TCE_INDIRECT 0x13C #define H_VTERM_PARTNER_INFO 0x150 diff --git a/include/asm-ppc64/plpar_wrappers.h b/include/asm-ppc64/plpar_wrappers.h index f4a5fb7d67..72dd2449ee 100644 --- a/include/asm-ppc64/plpar_wrappers.h +++ b/include/asm-ppc64/plpar_wrappers.h @@ -107,5 +107,14 @@ static inline long plpar_put_term_char(unsigned long termno, lbuf[1]); } +static inline long plpar_set_xdabr(unsigned long address, unsigned long flags) +{ + return plpar_hcall_norets(H_SET_XDABR, address, flags); +} + +static inline long plpar_set_dabr(unsigned long val) +{ + return plpar_hcall_norets(H_SET_DABR, val); +} #endif /* _PPC64_PLPAR_WRAPPERS_H */ diff --git a/include/asm-ppc64/processor.h b/include/asm-ppc64/processor.h index 8bd7aa9593..4146189006 100644 --- a/include/asm-ppc64/processor.h +++ b/include/asm-ppc64/processor.h @@ -433,6 +433,7 @@ struct thread_struct { unsigned long start_tb; /* Start purr when proc switched in */ unsigned long accum_tb; /* Total accumilated purr for process */ unsigned long vdso_base; /* base of the vDSO library */ + unsigned long dabr; /* Data address breakpoint register */ #ifdef CONFIG_ALTIVEC /* Complete AltiVec register set */ vector128 vr[32] __attribute((aligned(16))); diff --git a/include/asm-ppc64/ptrace-common.h b/include/asm-ppc64/ptrace-common.h index bd0f84c27b..b1babb7296 100644 --- a/include/asm-ppc64/ptrace-common.h +++ b/include/asm-ppc64/ptrace-common.h @@ -13,6 +13,7 @@ #define _PPC64_PTRACE_COMMON_H #include +#include /* * Set of msr bits that gdb can change on behalf of a process. @@ -141,4 +142,23 @@ static inline int set_vrregs(struct task_struct *task, } #endif +static inline int ptrace_set_debugreg(struct task_struct *task, + unsigned long addr, unsigned long data) +{ + /* We only support one DABR and no IABRS at the moment */ + if (addr > 0) + return -EINVAL; + + /* The bottom 3 bits are flags */ + if ((data & ~0x7UL) >= TASK_SIZE) + return -EIO; + + /* Ensure translation is on */ + if (data && !(data & DABR_TRANSLATION)) + return -EIO; + + task->thread.dabr = data; + return 0; +} + #endif /* _PPC64_PTRACE_COMMON_H */ diff --git a/include/asm-ppc64/system.h b/include/asm-ppc64/system.h index c0396428cc..375015c62f 100644 --- a/include/asm-ppc64/system.h +++ b/include/asm-ppc64/system.h @@ -101,6 +101,9 @@ static inline int debugger_dabr_match(struct pt_regs *regs) { return 0; } static inline int debugger_fault_handler(struct pt_regs *regs) { return 0; } #endif +extern int set_dabr(unsigned long dabr); +extern void _exception(int signr, struct pt_regs *regs, int code, + unsigned long addr); extern int fix_alignment(struct pt_regs *regs); extern void bad_page_fault(struct pt_regs *regs, unsigned long address, int sig); -- 2.39.5