diff options
Diffstat (limited to 'arch/sparc/kernel')
| -rw-r--r-- | arch/sparc/kernel/Makefile | 1 | ||||
| -rw-r--r-- | arch/sparc/kernel/iommu.c | 4 | ||||
| -rw-r--r-- | arch/sparc/kernel/ioport.c | 4 | ||||
| -rw-r--r-- | arch/sparc/kernel/leon_kernel.c | 56 | ||||
| -rw-r--r-- | arch/sparc/kernel/nmi.c | 44 | ||||
| -rw-r--r-- | arch/sparc/kernel/pci_sun4v.c | 7 | ||||
| -rw-r--r-- | arch/sparc/kernel/power.c | 7 | ||||
| -rw-r--r-- | arch/sparc/kernel/ptrace_64.c | 54 | ||||
| -rw-r--r-- | arch/sparc/kernel/signal_64.c | 2 | ||||
| -rw-r--r-- | arch/sparc/kernel/sysfs.c | 45 | ||||
| -rw-r--r-- | arch/sparc/kernel/traps_64.c | 4 | ||||
| -rw-r--r-- | arch/sparc/kernel/ttable_64.S | 2 | ||||
| -rw-r--r-- | arch/sparc/kernel/uprobes.c | 331 |
13 files changed, 480 insertions, 81 deletions
diff --git a/arch/sparc/kernel/Makefile b/arch/sparc/kernel/Makefile index fa3c02d41138..aac609889ee4 100644 --- a/arch/sparc/kernel/Makefile +++ b/arch/sparc/kernel/Makefile @@ -116,4 +116,5 @@ obj-$(CONFIG_COMPAT) += $(audit--y) pc--$(CONFIG_PERF_EVENTS) := perf_event.o obj-$(CONFIG_SPARC64) += $(pc--y) +obj-$(CONFIG_UPROBES) += uprobes.o obj-$(CONFIG_SPARC64) += jump_label.o diff --git a/arch/sparc/kernel/iommu.c b/arch/sparc/kernel/iommu.c index 852a3291db96..9df997995f6b 100644 --- a/arch/sparc/kernel/iommu.c +++ b/arch/sparc/kernel/iommu.c @@ -415,7 +415,7 @@ static void dma_4u_unmap_page(struct device *dev, dma_addr_t bus_addr, ctx = (iopte_val(*base) & IOPTE_CONTEXT) >> 47UL; /* Step 1: Kick data out of streaming buffers if necessary. */ - if (strbuf->strbuf_enabled) + if (strbuf->strbuf_enabled && !(attrs & DMA_ATTR_SKIP_CPU_SYNC)) strbuf_flush(strbuf, iommu, bus_addr, ctx, npages, direction); @@ -640,7 +640,7 @@ static void dma_4u_unmap_sg(struct device *dev, struct scatterlist *sglist, base = iommu->page_table + entry; dma_handle &= IO_PAGE_MASK; - if (strbuf->strbuf_enabled) + if (strbuf->strbuf_enabled && !(attrs & DMA_ATTR_SKIP_CPU_SYNC)) strbuf_flush(strbuf, iommu, dma_handle, ctx, npages, direction); diff --git a/arch/sparc/kernel/ioport.c b/arch/sparc/kernel/ioport.c index 2344103414d1..6ffaec44931a 100644 --- a/arch/sparc/kernel/ioport.c +++ b/arch/sparc/kernel/ioport.c @@ -527,7 +527,7 @@ static dma_addr_t pci32_map_page(struct device *dev, struct page *page, static void pci32_unmap_page(struct device *dev, dma_addr_t ba, size_t size, enum dma_data_direction dir, unsigned long attrs) { - if (dir != PCI_DMA_TODEVICE) + if (dir != PCI_DMA_TODEVICE && !(attrs & DMA_ATTR_SKIP_CPU_SYNC)) dma_make_coherent(ba, PAGE_ALIGN(size)); } @@ -572,7 +572,7 @@ static void pci32_unmap_sg(struct device *dev, struct scatterlist *sgl, struct scatterlist *sg; int n; - if (dir != PCI_DMA_TODEVICE) { + if (dir != PCI_DMA_TODEVICE && !(attrs & DMA_ATTR_SKIP_CPU_SYNC)) { for_each_sg(sgl, sg, nents, n) { dma_make_coherent(sg_phys(sg), PAGE_ALIGN(sg->length)); } diff --git a/arch/sparc/kernel/leon_kernel.c b/arch/sparc/kernel/leon_kernel.c index 33cd171d933e..afcdd5e4f43f 100644 --- a/arch/sparc/kernel/leon_kernel.c +++ b/arch/sparc/kernel/leon_kernel.c @@ -349,37 +349,37 @@ void __init leon_init_timers(void) /* Find GPTIMER Timer Registers base address otherwise bail out. */ nnp = rootnp; - do { - np = of_find_node_by_name(nnp, "GAISLER_GPTIMER"); - if (!np) { - np = of_find_node_by_name(nnp, "01_011"); - if (!np) - goto bad; - } - ampopts = 0; - pp = of_find_property(np, "ampopts", &len); - if (pp) { - ampopts = *(int *)pp->value; - if (ampopts == 0) { - /* Skip this instance, resource already - * allocated by other OS */ - nnp = np; - continue; - } +retry: + np = of_find_node_by_name(nnp, "GAISLER_GPTIMER"); + if (!np) { + np = of_find_node_by_name(nnp, "01_011"); + if (!np) + goto bad; + } + + ampopts = 0; + pp = of_find_property(np, "ampopts", &len); + if (pp) { + ampopts = *(int *)pp->value; + if (ampopts == 0) { + /* Skip this instance, resource already + * allocated by other OS */ + nnp = np; + goto retry; } + } + + /* Select Timer-Instance on Timer Core. Default is zero */ + leon3_gptimer_idx = ampopts & 0x7; - /* Select Timer-Instance on Timer Core. Default is zero */ - leon3_gptimer_idx = ampopts & 0x7; - - pp = of_find_property(np, "reg", &len); - if (pp) - leon3_gptimer_regs = *(struct leon3_gptimer_regs_map **) - pp->value; - pp = of_find_property(np, "interrupts", &len); - if (pp) - leon3_gptimer_irq = *(unsigned int *)pp->value; - } while (0); + pp = of_find_property(np, "reg", &len); + if (pp) + leon3_gptimer_regs = *(struct leon3_gptimer_regs_map **) + pp->value; + pp = of_find_property(np, "interrupts", &len); + if (pp) + leon3_gptimer_irq = *(unsigned int *)pp->value; if (!(leon3_gptimer_regs && leon3_irqctrl_regs && leon3_gptimer_irq)) goto bad; diff --git a/arch/sparc/kernel/nmi.c b/arch/sparc/kernel/nmi.c index a9973bb4a1b2..95e73c63c99d 100644 --- a/arch/sparc/kernel/nmi.c +++ b/arch/sparc/kernel/nmi.c @@ -42,7 +42,7 @@ static int panic_on_timeout; */ atomic_t nmi_active = ATOMIC_INIT(0); /* oprofile uses this */ EXPORT_SYMBOL(nmi_active); - +static int nmi_init_done; static unsigned int nmi_hz = HZ; static DEFINE_PER_CPU(short, wd_enabled); static int endflag __initdata; @@ -153,6 +153,8 @@ static void report_broken_nmi(int cpu, int *prev_nmi_count) void stop_nmi_watchdog(void *unused) { + if (!__this_cpu_read(wd_enabled)) + return; pcr_ops->write_pcr(0, pcr_ops->pcr_nmi_disable); __this_cpu_write(wd_enabled, 0); atomic_dec(&nmi_active); @@ -207,6 +209,9 @@ error: void start_nmi_watchdog(void *unused) { + if (__this_cpu_read(wd_enabled)) + return; + __this_cpu_write(wd_enabled, 1); atomic_inc(&nmi_active); @@ -259,6 +264,8 @@ int __init nmi_init(void) } } + nmi_init_done = 1; + return err; } @@ -270,3 +277,38 @@ static int __init setup_nmi_watchdog(char *str) return 0; } __setup("nmi_watchdog=", setup_nmi_watchdog); + +/* + * sparc specific NMI watchdog enable function. + * Enables watchdog if it is not enabled already. + */ +int watchdog_nmi_enable(unsigned int cpu) +{ + if (atomic_read(&nmi_active) == -1) { + pr_warn("NMI watchdog cannot be enabled or disabled\n"); + return -1; + } + + /* + * watchdog thread could start even before nmi_init is called. + * Just Return in that case. Let nmi_init finish the init + * process first. + */ + if (!nmi_init_done) + return 0; + + smp_call_function_single(cpu, start_nmi_watchdog, NULL, 1); + + return 0; +} +/* + * sparc specific NMI watchdog disable function. + * Disables watchdog if it is not disabled already. + */ +void watchdog_nmi_disable(unsigned int cpu) +{ + if (atomic_read(&nmi_active) == -1) + pr_warn_once("NMI watchdog cannot be enabled or disabled\n"); + else + smp_call_function_single(cpu, stop_nmi_watchdog, NULL, 1); +} diff --git a/arch/sparc/kernel/pci_sun4v.c b/arch/sparc/kernel/pci_sun4v.c index 06981cc716b6..f4daccd12bf5 100644 --- a/arch/sparc/kernel/pci_sun4v.c +++ b/arch/sparc/kernel/pci_sun4v.c @@ -242,6 +242,7 @@ static void *dma_4v_alloc_coherent(struct device *dev, size_t size, return ret; iommu_map_fail: + local_irq_restore(flags); iommu_tbl_range_free(tbl, *dma_addrp, npages, IOMMU_ERROR_CODE); range_alloc_fail: @@ -414,6 +415,7 @@ bad: return DMA_ERROR_CODE; iommu_map_fail: + local_irq_restore(flags); iommu_tbl_range_free(tbl, bus_addr, npages, IOMMU_ERROR_CODE); return DMA_ERROR_CODE; } @@ -478,11 +480,10 @@ static int dma_4v_map_sg(struct device *dev, struct scatterlist *sglist, BUG_ON(direction == DMA_NONE); iommu = dev->archdata.iommu; - atu = iommu->atu; - if (nelems == 0 || !iommu) return 0; - + atu = iommu->atu; + prot = HV_PCI_MAP_ATTR_READ; if (direction != DMA_TO_DEVICE) prot |= HV_PCI_MAP_ATTR_WRITE; diff --git a/arch/sparc/kernel/power.c b/arch/sparc/kernel/power.c index 1836cb965ff8..4b60f385c98f 100644 --- a/arch/sparc/kernel/power.c +++ b/arch/sparc/kernel/power.c @@ -67,9 +67,4 @@ static struct platform_driver power_driver = { }, }; -static int __init power_init(void) -{ - return platform_driver_register(&power_driver); -} - -device_initcall(power_init); +builtin_platform_driver(power_driver); diff --git a/arch/sparc/kernel/ptrace_64.c b/arch/sparc/kernel/ptrace_64.c index ac082dd8c67d..96494b2ef41f 100644 --- a/arch/sparc/kernel/ptrace_64.c +++ b/arch/sparc/kernel/ptrace_64.c @@ -46,6 +46,43 @@ /* #define ALLOW_INIT_TRACING */ +struct pt_regs_offset { + const char *name; + int offset; +}; + +#define REG_OFFSET_NAME(n, r) \ + {.name = n, .offset = (PT_V9_##r)} +#define REG_OFFSET_END {.name = NULL, .offset = 0} + +static const struct pt_regs_offset regoffset_table[] = { + REG_OFFSET_NAME("g0", G0), + REG_OFFSET_NAME("g1", G1), + REG_OFFSET_NAME("g2", G2), + REG_OFFSET_NAME("g3", G3), + REG_OFFSET_NAME("g4", G4), + REG_OFFSET_NAME("g5", G5), + REG_OFFSET_NAME("g6", G6), + REG_OFFSET_NAME("g7", G7), + + REG_OFFSET_NAME("i0", I0), + REG_OFFSET_NAME("i1", I1), + REG_OFFSET_NAME("i2", I2), + REG_OFFSET_NAME("i3", I3), + REG_OFFSET_NAME("i4", I4), + REG_OFFSET_NAME("i5", I5), + REG_OFFSET_NAME("i6", I6), + REG_OFFSET_NAME("i7", I7), + + REG_OFFSET_NAME("tstate", TSTATE), + REG_OFFSET_NAME("pc", TPC), + REG_OFFSET_NAME("npc", TNPC), + REG_OFFSET_NAME("y", Y), + REG_OFFSET_NAME("lr", I7), + + REG_OFFSET_END, +}; + /* * Called by kernel/ptrace.c when detaching.. * @@ -1107,3 +1144,20 @@ asmlinkage void syscall_trace_leave(struct pt_regs *regs) if (test_thread_flag(TIF_NOHZ)) user_enter(); } + +/** + * regs_query_register_offset() - query register offset from its name + * @name: the name of a register + * + * regs_query_register_offset() returns the offset of a register in struct + * pt_regs from its name. If the name is invalid, this returns -EINVAL; + */ +int regs_query_register_offset(const char *name) +{ + const struct pt_regs_offset *roff; + + for (roff = regoffset_table; roff->name != NULL; roff++) + if (!strcmp(roff->name, name)) + return roff->offset; + return -EINVAL; +} diff --git a/arch/sparc/kernel/signal_64.c b/arch/sparc/kernel/signal_64.c index 5ee930c48f4c..c782c9b716db 100644 --- a/arch/sparc/kernel/signal_64.c +++ b/arch/sparc/kernel/signal_64.c @@ -545,6 +545,8 @@ static void do_signal(struct pt_regs *regs, unsigned long orig_i0) void do_notify_resume(struct pt_regs *regs, unsigned long orig_i0, unsigned long thread_info_flags) { user_exit(); + if (thread_info_flags & _TIF_UPROBE) + uprobe_notify_resume(regs); if (thread_info_flags & _TIF_SIGPENDING) do_signal(regs, orig_i0); if (thread_info_flags & _TIF_NOTIFY_RESUME) { diff --git a/arch/sparc/kernel/sysfs.c b/arch/sparc/kernel/sysfs.c index fa8e21abb5e0..4808b6d23455 100644 --- a/arch/sparc/kernel/sysfs.c +++ b/arch/sparc/kernel/sysfs.c @@ -221,7 +221,7 @@ static struct device_attribute cpu_core_attrs[] = { static DEFINE_PER_CPU(struct cpu, cpu_devices); -static void register_cpu_online(unsigned int cpu) +static int register_cpu_online(unsigned int cpu) { struct cpu *c = &per_cpu(cpu_devices, cpu); struct device *s = &c->dev; @@ -231,11 +231,12 @@ static void register_cpu_online(unsigned int cpu) device_create_file(s, &cpu_core_attrs[i]); register_mmu_stats(s); + return 0; } -#ifdef CONFIG_HOTPLUG_CPU -static void unregister_cpu_online(unsigned int cpu) +static int unregister_cpu_online(unsigned int cpu) { +#ifdef CONFIG_HOTPLUG_CPU struct cpu *c = &per_cpu(cpu_devices, cpu); struct device *s = &c->dev; int i; @@ -243,33 +244,10 @@ static void unregister_cpu_online(unsigned int cpu) unregister_mmu_stats(s); for (i = 0; i < ARRAY_SIZE(cpu_core_attrs); i++) device_remove_file(s, &cpu_core_attrs[i]); -} -#endif - -static int sysfs_cpu_notify(struct notifier_block *self, - unsigned long action, void *hcpu) -{ - unsigned int cpu = (unsigned int)(long)hcpu; - - switch (action) { - case CPU_ONLINE: - case CPU_ONLINE_FROZEN: - register_cpu_online(cpu); - break; -#ifdef CONFIG_HOTPLUG_CPU - case CPU_DEAD: - case CPU_DEAD_FROZEN: - unregister_cpu_online(cpu); - break; #endif - } - return NOTIFY_OK; + return 0; } -static struct notifier_block sysfs_cpu_nb = { - .notifier_call = sysfs_cpu_notify, -}; - static void __init check_mmu_stats(void) { unsigned long dummy1, err; @@ -294,26 +272,21 @@ static void register_nodes(void) static int __init topology_init(void) { - int cpu; + int cpu, ret; register_nodes(); check_mmu_stats(); - cpu_notifier_register_begin(); - for_each_possible_cpu(cpu) { struct cpu *c = &per_cpu(cpu_devices, cpu); register_cpu(c, cpu); - if (cpu_online(cpu)) - register_cpu_online(cpu); } - __register_cpu_notifier(&sysfs_cpu_nb); - - cpu_notifier_register_done(); - + ret = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "sparc/topology:online", + register_cpu_online, unregister_cpu_online); + WARN_ON(ret < 0); return 0; } diff --git a/arch/sparc/kernel/traps_64.c b/arch/sparc/kernel/traps_64.c index 4094a51b1970..496fa926e1e0 100644 --- a/arch/sparc/kernel/traps_64.c +++ b/arch/sparc/kernel/traps_64.c @@ -85,7 +85,7 @@ static void dump_tl1_traplog(struct tl1_traplog *p) void bad_trap(struct pt_regs *regs, long lvl) { - char buffer[32]; + char buffer[36]; siginfo_t info; if (notify_die(DIE_TRAP, "bad trap", regs, @@ -116,7 +116,7 @@ void bad_trap(struct pt_regs *regs, long lvl) void bad_trap_tl1(struct pt_regs *regs, long lvl) { - char buffer[32]; + char buffer[36]; if (notify_die(DIE_TRAP_TL1, "bad trap tl1", regs, 0, lvl, SIGTRAP) == NOTIFY_STOP) diff --git a/arch/sparc/kernel/ttable_64.S b/arch/sparc/kernel/ttable_64.S index c6dfdaa29e20..7bd8f6556352 100644 --- a/arch/sparc/kernel/ttable_64.S +++ b/arch/sparc/kernel/ttable_64.S @@ -165,7 +165,7 @@ tl0_resv169: BTRAP(0x169) BTRAP(0x16a) BTRAP(0x16b) BTRAP(0x16c) tl0_linux64: LINUX_64BIT_SYSCALL_TRAP tl0_gsctx: TRAP(sparc64_get_context) TRAP(sparc64_set_context) tl0_resv170: KPROBES_TRAP(0x170) KPROBES_TRAP(0x171) KGDB_TRAP(0x172) -tl0_resv173: BTRAP(0x173) BTRAP(0x174) BTRAP(0x175) BTRAP(0x176) BTRAP(0x177) +tl0_resv173: UPROBES_TRAP(0x173) UPROBES_TRAP(0x174) BTRAP(0x175) BTRAP(0x176) BTRAP(0x177) tl0_resv178: BTRAP(0x178) BTRAP(0x179) BTRAP(0x17a) BTRAP(0x17b) BTRAP(0x17c) tl0_resv17d: BTRAP(0x17d) BTRAP(0x17e) BTRAP(0x17f) #define BTRAPS(x) BTRAP(x) BTRAP(x+1) BTRAP(x+2) BTRAP(x+3) BTRAP(x+4) BTRAP(x+5) BTRAP(x+6) BTRAP(x+7) diff --git a/arch/sparc/kernel/uprobes.c b/arch/sparc/kernel/uprobes.c new file mode 100644 index 000000000000..b68314050602 --- /dev/null +++ b/arch/sparc/kernel/uprobes.c @@ -0,0 +1,331 @@ +/* + * User-space Probes (UProbes) for sparc + * + * Copyright (C) 2013 Oracle Inc. + * + * This program is free software: you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation, either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program. If not, see <http://www.gnu.org/licenses/>. + * + * Authors: + * Jose E. Marchesi <jose.marchesi@oracle.com> + * Eric Saint Etienne <eric.saint.etienne@oracle.com> + */ + +#include <linux/kernel.h> +#include <linux/highmem.h> +#include <linux/uprobes.h> +#include <linux/uaccess.h> +#include <linux/sched.h> /* For struct task_struct */ +#include <linux/kdebug.h> + +#include <asm/cacheflush.h> +#include <asm/uaccess.h> + +/* Compute the address of the breakpoint instruction and return it. + * + * Note that uprobe_get_swbp_addr is defined as a weak symbol in + * kernel/events/uprobe.c. + */ +unsigned long uprobe_get_swbp_addr(struct pt_regs *regs) +{ + return instruction_pointer(regs); +} + +static void copy_to_page(struct page *page, unsigned long vaddr, + const void *src, int len) +{ + void *kaddr = kmap_atomic(page); + + memcpy(kaddr + (vaddr & ~PAGE_MASK), src, len); + kunmap_atomic(kaddr); +} + +/* Fill in the xol area with the probed instruction followed by the + * single-step trap. Some fixups in the copied instruction are + * performed at this point. + * + * Note that uprobe_xol_copy is defined as a weak symbol in + * kernel/events/uprobe.c. + */ +void arch_uprobe_copy_ixol(struct page *page, unsigned long vaddr, + void *src, unsigned long len) +{ + const u32 stp_insn = UPROBE_STP_INSN; + u32 insn = *(u32 *) src; + + /* Branches annulling their delay slot must be fixed to not do + * so. Clearing the annul bit on these instructions we can be + * sure the single-step breakpoint in the XOL slot will be + * executed. + */ + + u32 op = (insn >> 30) & 0x3; + u32 op2 = (insn >> 22) & 0x7; + + if (op == 0 && + (op2 == 1 || op2 == 2 || op2 == 3 || op2 == 5 || op2 == 6) && + (insn & ANNUL_BIT) == ANNUL_BIT) + insn &= ~ANNUL_BIT; + + copy_to_page(page, vaddr, &insn, len); + copy_to_page(page, vaddr+len, &stp_insn, 4); +} + + +/* Instruction analysis/validity. + * + * This function returns 0 on success or a -ve number on error. + */ +int arch_uprobe_analyze_insn(struct arch_uprobe *auprobe, + struct mm_struct *mm, unsigned long addr) +{ + /* Any unsupported instruction? Then return -EINVAL */ + return 0; +} + +/* If INSN is a relative control transfer instruction, return the + * corrected branch destination value. + * + * Note that regs->tpc and regs->tnpc still hold the values of the + * program counters at the time of the single-step trap due to the + * execution of the UPROBE_STP_INSN at utask->xol_vaddr + 4. + * + */ +static unsigned long relbranch_fixup(u32 insn, struct uprobe_task *utask, + struct pt_regs *regs) +{ + /* Branch not taken, no mods necessary. */ + if (regs->tnpc == regs->tpc + 0x4UL) + return utask->autask.saved_tnpc + 0x4UL; + + /* The three cases are call, branch w/prediction, + * and traditional branch. + */ + if ((insn & 0xc0000000) == 0x40000000 || + (insn & 0xc1c00000) == 0x00400000 || + (insn & 0xc1c00000) == 0x00800000) { + unsigned long real_pc = (unsigned long) utask->vaddr; + unsigned long ixol_addr = utask->xol_vaddr; + + /* The instruction did all the work for us + * already, just apply the offset to the correct + * instruction location. + */ + return (real_pc + (regs->tnpc - ixol_addr)); + } + + /* It is jmpl or some other absolute PC modification instruction, + * leave NPC as-is. + */ + return regs->tnpc; +} + +/* If INSN is an instruction which writes its PC location + * into a destination register, fix that up. + */ +static int retpc_fixup(struct pt_regs *regs, u32 insn, + unsigned long real_pc) +{ + unsigned long *slot = NULL; + int rc = 0; + + /* Simplest case is 'call', which always uses %o7 */ + if ((insn & 0xc0000000) == 0x40000000) + slot = ®s->u_regs[UREG_I7]; + + /* 'jmpl' encodes the register inside of the opcode */ + if ((insn & 0xc1f80000) == 0x81c00000) { + unsigned long rd = ((insn >> 25) & 0x1f); + + if (rd <= 15) { + slot = ®s->u_regs[rd]; + } else { + unsigned long fp = regs->u_regs[UREG_FP]; + /* Hard case, it goes onto the stack. */ + flushw_all(); + + rd -= 16; + if (test_thread_64bit_stack(fp)) { + unsigned long __user *uslot = + (unsigned long __user *) (fp + STACK_BIAS) + rd; + rc = __put_user(real_pc, uslot); + } else { + unsigned int __user *uslot = (unsigned int + __user *) fp + rd; + rc = __put_user((u32) real_pc, uslot); + } + } + } + if (slot != NULL) + *slot = real_pc; + return rc; +} + +/* Single-stepping can be avoided for certain instructions: NOPs and + * instructions that can be emulated. This function determines + * whether the instruction where the uprobe is installed falls in one + * of these cases and emulates it. + * + * This function returns true if the single-stepping can be skipped, + * false otherwise. + */ +bool arch_uprobe_skip_sstep(struct arch_uprobe *auprobe, struct pt_regs *regs) +{ + /* We currently only emulate NOP instructions. + */ + + if (auprobe->ixol == (1 << 24)) { + regs->tnpc += 4; + regs->tpc += 4; + return true; + } + + return false; +} + +/* Prepare to execute out of line. At this point + * current->utask->xol_vaddr points to an allocated XOL slot properly + * initialized with the original instruction and the single-stepping + * trap instruction. + * + * This function returns 0 on success, any other number on error. + */ +int arch_uprobe_pre_xol(struct arch_uprobe *auprobe, struct pt_regs *regs) +{ + struct uprobe_task *utask = current->utask; + struct arch_uprobe_task *autask = ¤t->utask->autask; + + /* Save the current program counters so they can be restored + * later. + */ + autask->saved_tpc = regs->tpc; + autask->saved_tnpc = regs->tnpc; + + /* Adjust PC and NPC so the first instruction in the XOL slot + * will be executed by the user task. + */ + instruction_pointer_set(regs, utask->xol_vaddr); + + return 0; +} + +/* Prepare to resume execution after the single-step. Called after + * single-stepping. To avoid the SMP problems that can occur when we + * temporarily put back the original opcode to single-step, we + * single-stepped a copy of the instruction. + * + * This function returns 0 on success, any other number on error. + */ +int arch_uprobe_post_xol(struct arch_uprobe *auprobe, struct pt_regs *regs) +{ + struct uprobe_task *utask = current->utask; + struct arch_uprobe_task *autask = &utask->autask; + u32 insn = auprobe->ixol; + int rc = 0; + + if (utask->state == UTASK_SSTEP_ACK) { + regs->tnpc = relbranch_fixup(insn, utask, regs); + regs->tpc = autask->saved_tnpc; + rc = retpc_fixup(regs, insn, (unsigned long) utask->vaddr); + } else { + regs->tnpc = utask->vaddr+4; + regs->tpc = autask->saved_tnpc+4; + } + return rc; +} + +/* Handler for uprobe traps. This is called from the traps table and + * triggers the proper die notification. + */ +asmlinkage void uprobe_trap(struct pt_regs *regs, + unsigned long trap_level) +{ + BUG_ON(trap_level != 0x173 && trap_level != 0x174); + + /* We are only interested in user-mode code. Uprobe traps + * shall not be present in kernel code. + */ + if (!user_mode(regs)) { + local_irq_enable(); + bad_trap(regs, trap_level); + return; + } + + /* trap_level == 0x173 --> ta 0x73 + * trap_level == 0x174 --> ta 0x74 + */ + if (notify_die((trap_level == 0x173) ? DIE_BPT : DIE_SSTEP, + (trap_level == 0x173) ? "bpt" : "sstep", + regs, 0, trap_level, SIGTRAP) != NOTIFY_STOP) + bad_trap(regs, trap_level); +} + +/* Callback routine for handling die notifications. +*/ +int arch_uprobe_exception_notify(struct notifier_block *self, + unsigned long val, void *data) +{ + int ret = NOTIFY_DONE; + struct die_args *args = (struct die_args *)data; + + /* We are only interested in userspace traps */ + if (args->regs && !user_mode(args->regs)) + return NOTIFY_DONE; + + switch (val) { + case DIE_BPT: + if (uprobe_pre_sstep_notifier(args->regs)) + ret = NOTIFY_STOP; + break; + + case DIE_SSTEP: + if (uprobe_post_sstep_notifier(args->regs)) + ret = NOTIFY_STOP; + + default: + break; + } + + return ret; +} + +/* This function gets called when a XOL instruction either gets + * trapped or the thread has a fatal signal, so reset the instruction + * pointer to its probed address. + */ +void arch_uprobe_abort_xol(struct arch_uprobe *auprobe, struct pt_regs *regs) +{ + struct uprobe_task *utask = current->utask; + + instruction_pointer_set(regs, utask->vaddr); +} + +/* If xol insn itself traps and generates a signal(Say, + * SIGILL/SIGSEGV/etc), then detect the case where a singlestepped + * instruction jumps back to its own address. + */ +bool arch_uprobe_xol_was_trapped(struct task_struct *t) +{ + return false; +} + +unsigned long +arch_uretprobe_hijack_return_addr(unsigned long trampoline_vaddr, + struct pt_regs *regs) +{ + unsigned long orig_ret_vaddr = regs->u_regs[UREG_I7]; + + regs->u_regs[UREG_I7] = trampoline_vaddr-8; + + return orig_ret_vaddr + 8; +} |