From 9422de3e953d0e60eb95f5430a9dd803eec1c6d7 Mon Sep 17 00:00:00 2001 From: Michael Neuling Date: Thu, 20 Dec 2012 14:06:44 +0000 Subject: powerpc: Hardware breakpoints rewrite to handle non DABR breakpoint registers This is a rewrite so that we don't assume we are using the DABR throughout the code. We now use the arch_hw_breakpoint to store the breakpoint in a generic manner in the thread_struct, rather than storing the raw DABR value. The ptrace GET/SET_DEBUGREG interface currently passes the raw DABR in from userspace. We keep this functionality, so that future changes (like the POWER8 DAWR), will still fake the DABR to userspace. Signed-off-by: Michael Neuling Signed-off-by: Benjamin Herrenschmidt --- arch/powerpc/kernel/ptrace.c | 60 +++++++++++++++++++++++--------------------- 1 file changed, 32 insertions(+), 28 deletions(-) (limited to 'arch/powerpc/kernel/ptrace.c') diff --git a/arch/powerpc/kernel/ptrace.c b/arch/powerpc/kernel/ptrace.c index c4970004d44d..d4afcccf1238 100644 --- a/arch/powerpc/kernel/ptrace.c +++ b/arch/powerpc/kernel/ptrace.c @@ -905,6 +905,9 @@ int ptrace_set_debugreg(struct task_struct *task, unsigned long addr, struct perf_event *bp; struct perf_event_attr attr; #endif /* CONFIG_HAVE_HW_BREAKPOINT */ +#ifndef CONFIG_PPC_ADV_DEBUG_REGS + struct arch_hw_breakpoint hw_brk; +#endif /* For ppc64 we support one DABR and no IABR's at the moment (ppc64). * For embedded processors we support one DAC and no IAC's at the @@ -931,14 +934,17 @@ int ptrace_set_debugreg(struct task_struct *task, unsigned long addr, */ /* Ensure breakpoint translation bit is set */ - if (data && !(data & DABR_TRANSLATION)) + if (data && !(data & HW_BRK_TYPE_TRANSLATE)) return -EIO; + hw_brk.address = data & (~HW_BRK_TYPE_DABR); + hw_brk.type = (data & HW_BRK_TYPE_DABR) | HW_BRK_TYPE_PRIV_ALL; + hw_brk.len = 8; #ifdef CONFIG_HAVE_HW_BREAKPOINT if (ptrace_get_breakpoints(task) < 0) return -ESRCH; bp = thread->ptrace_bps[0]; - if ((!data) || !(data & (DABR_DATA_WRITE | DABR_DATA_READ))) { + if ((!data) || !(hw_brk.type & HW_BRK_TYPE_RDWR)) { if (bp) { unregister_hw_breakpoint(bp); thread->ptrace_bps[0] = NULL; @@ -948,10 +954,8 @@ int ptrace_set_debugreg(struct task_struct *task, unsigned long addr, } if (bp) { attr = bp->attr; - attr.bp_addr = data & ~HW_BREAKPOINT_ALIGN; - arch_bp_generic_fields(data & - (DABR_DATA_WRITE | DABR_DATA_READ), - &attr.bp_type); + attr.bp_addr = hw_brk.address; + arch_bp_generic_fields(hw_brk.type, &attr.bp_type); /* Enable breakpoint */ attr.disabled = false; @@ -963,16 +967,15 @@ int ptrace_set_debugreg(struct task_struct *task, unsigned long addr, } thread->ptrace_bps[0] = bp; ptrace_put_breakpoints(task); - thread->dabr = data; - thread->dabrx = DABRX_ALL; + thread->hw_brk = hw_brk; return 0; } /* Create a new breakpoint request if one doesn't exist already */ hw_breakpoint_init(&attr); - attr.bp_addr = data & ~HW_BREAKPOINT_ALIGN; - arch_bp_generic_fields(data & (DABR_DATA_WRITE | DABR_DATA_READ), - &attr.bp_type); + attr.bp_addr = hw_brk.address; + arch_bp_generic_fields(hw_brk.type, + &attr.bp_type); thread->ptrace_bps[0] = bp = register_user_hw_breakpoint(&attr, ptrace_triggered, NULL, task); @@ -985,10 +988,7 @@ int ptrace_set_debugreg(struct task_struct *task, unsigned long addr, ptrace_put_breakpoints(task); #endif /* CONFIG_HAVE_HW_BREAKPOINT */ - - /* Move contents to the DABR register */ - task->thread.dabr = data; - task->thread.dabrx = DABRX_ALL; + task->thread.hw_brk = hw_brk; #else /* CONFIG_PPC_ADV_DEBUG_REGS */ /* As described above, it was assumed 3 bits were passed with the data * address, but we will assume only the mode bits will be passed @@ -1349,7 +1349,7 @@ static long ppc_set_hwdebug(struct task_struct *child, struct perf_event_attr attr; #endif /* CONFIG_HAVE_HW_BREAKPOINT */ #ifndef CONFIG_PPC_ADV_DEBUG_REGS - unsigned long dabr; + struct arch_hw_breakpoint brk; #endif if (bp_info->version != 1) @@ -1397,12 +1397,12 @@ static long ppc_set_hwdebug(struct task_struct *child, if ((unsigned long)bp_info->addr >= TASK_SIZE) return -EIO; - dabr = (unsigned long)bp_info->addr & ~7UL; - dabr |= DABR_TRANSLATION; + brk.address = bp_info->addr & ~7UL; + brk.type = HW_BRK_TYPE_TRANSLATE; if (bp_info->trigger_type & PPC_BREAKPOINT_TRIGGER_READ) - dabr |= DABR_DATA_READ; + brk.type |= HW_BRK_TYPE_READ; if (bp_info->trigger_type & PPC_BREAKPOINT_TRIGGER_WRITE) - dabr |= DABR_DATA_WRITE; + brk.type |= HW_BRK_TYPE_WRITE; #ifdef CONFIG_HAVE_HW_BREAKPOINT if (ptrace_get_breakpoints(child) < 0) return -ESRCH; @@ -1427,8 +1427,7 @@ static long ppc_set_hwdebug(struct task_struct *child, hw_breakpoint_init(&attr); attr.bp_addr = (unsigned long)bp_info->addr & ~HW_BREAKPOINT_ALIGN; attr.bp_len = len; - arch_bp_generic_fields(dabr & (DABR_DATA_WRITE | DABR_DATA_READ), - &attr.bp_type); + arch_bp_generic_fields(brk.type, &attr.bp_type); thread->ptrace_bps[0] = bp = register_user_hw_breakpoint(&attr, ptrace_triggered, NULL, child); @@ -1445,11 +1444,10 @@ static long ppc_set_hwdebug(struct task_struct *child, if (bp_info->addr_mode != PPC_BREAKPOINT_MODE_EXACT) return -EINVAL; - if (child->thread.dabr) + if (child->thread.hw_brk.address) return -ENOSPC; - child->thread.dabr = dabr; - child->thread.dabrx = DABRX_ALL; + child->thread.hw_brk = brk; return 1; #endif /* !CONFIG_PPC_ADV_DEBUG_DVCS */ @@ -1495,10 +1493,11 @@ static long ppc_del_hwdebug(struct task_struct *child, long data) ptrace_put_breakpoints(child); return ret; #else /* CONFIG_HAVE_HW_BREAKPOINT */ - if (child->thread.dabr == 0) + if (child->thread.hw_brk.address == 0) return -ENOENT; - child->thread.dabr = 0; + child->thread.hw_brk.address = 0; + child->thread.hw_brk.type = 0; #endif /* CONFIG_HAVE_HW_BREAKPOINT */ return 0; @@ -1642,6 +1641,9 @@ long arch_ptrace(struct task_struct *child, long request, } case PTRACE_GET_DEBUGREG: { +#ifndef CONFIG_PPC_ADV_DEBUG_REGS + unsigned long dabr_fake; +#endif ret = -EINVAL; /* We only support one DABR and no IABRS at the moment */ if (addr > 0) @@ -1649,7 +1651,9 @@ long arch_ptrace(struct task_struct *child, long request, #ifdef CONFIG_PPC_ADV_DEBUG_REGS ret = put_user(child->thread.dac1, datalp); #else - ret = put_user(child->thread.dabr, datalp); + dabr_fake = ((child->thread.hw_brk.address & (~HW_BRK_TYPE_DABR)) | + (child->thread.hw_brk.type & HW_BRK_TYPE_DABR)); + ret = put_user(dabr_fake, datalp); #endif break; } -- cgit v1.2.3 From 1715a826a5b72d4fb882504d0babcea9aec8a0db Mon Sep 17 00:00:00 2001 From: Alexey Kardashevskiy Date: Thu, 10 Jan 2013 20:29:09 +0000 Subject: powerpc: Add DSCR support to ptrace The DSCR (aka Data Stream Control Register) is supported on some server PowerPC chips and allow some control over the prefetch of data streams. The kernel already supports DSCR value per thread but there is also a need in a ability to change it from an external process for the specific pid. The patch adds new register index PT_DSCR (index=44) which can be set/get by: ptrace(PTRACE_POKEUSER, traced_process, PT_DSCR << 3, dscr); dscr = ptrace(PTRACE_PEEKUSER, traced_process, PT_DSCR << 3, NULL); The patch does not increase PT_REGS_COUNT as the pt_regs struct has not been changed. Signed-off-by: Alexey Kardashevskiy Signed-off-by: Benjamin Herrenschmidt --- arch/powerpc/include/uapi/asm/ptrace.h | 1 + arch/powerpc/kernel/ptrace.c | 29 +++++++++++++++++++++++++++++ 2 files changed, 30 insertions(+) (limited to 'arch/powerpc/kernel/ptrace.c') diff --git a/arch/powerpc/include/uapi/asm/ptrace.h b/arch/powerpc/include/uapi/asm/ptrace.h index ee67a2bc91bb..5a4863c76b5f 100644 --- a/arch/powerpc/include/uapi/asm/ptrace.h +++ b/arch/powerpc/include/uapi/asm/ptrace.h @@ -108,6 +108,7 @@ struct pt_regs { #define PT_DAR 41 #define PT_DSISR 42 #define PT_RESULT 43 +#define PT_DSCR 44 #define PT_REGS_COUNT 44 #define PT_FPR0 48 /* each FP reg occupies 2 slots in this space */ diff --git a/arch/powerpc/kernel/ptrace.c b/arch/powerpc/kernel/ptrace.c index d4afcccf1238..245c1b6a0858 100644 --- a/arch/powerpc/kernel/ptrace.c +++ b/arch/powerpc/kernel/ptrace.c @@ -179,6 +179,30 @@ static int set_user_msr(struct task_struct *task, unsigned long msr) return 0; } +#ifdef CONFIG_PPC64 +static unsigned long get_user_dscr(struct task_struct *task) +{ + return task->thread.dscr; +} + +static int set_user_dscr(struct task_struct *task, unsigned long dscr) +{ + task->thread.dscr = dscr; + task->thread.dscr_inherit = 1; + return 0; +} +#else +static unsigned long get_user_dscr(struct task_struct *task) +{ + return -EIO; +} + +static int set_user_dscr(struct task_struct *task, unsigned long dscr) +{ + return -EIO; +} +#endif + /* * We prevent mucking around with the reserved area of trap * which are used internally by the kernel. @@ -200,6 +224,9 @@ unsigned long ptrace_get_reg(struct task_struct *task, int regno) if (regno == PT_MSR) return get_user_msr(task); + if (regno == PT_DSCR) + return get_user_dscr(task); + if (regno < (sizeof(struct pt_regs) / sizeof(unsigned long))) return ((unsigned long *)task->thread.regs)[regno]; @@ -218,6 +245,8 @@ int ptrace_put_reg(struct task_struct *task, int regno, unsigned long data) return set_user_msr(task, data); if (regno == PT_TRAP) return set_user_trap(task, data); + if (regno == PT_DSCR) + return set_user_dscr(task, data); if (regno <= PT_MAX_PUT_REG) { ((unsigned long *)task->thread.regs)[regno] = data; -- cgit v1.2.3