diff options
| -rw-r--r-- | arch/x86/include/asm/a.out-core.h | 8 | ||||
| -rw-r--r-- | arch/x86/include/asm/debugreg.h | 29 | ||||
| -rw-r--r-- | arch/x86/include/asm/hw_breakpoint.h | 55 | ||||
| -rw-r--r-- | arch/x86/include/asm/processor.h | 8 | ||||
| -rw-r--r-- | arch/x86/kernel/process.c | 16 | ||||
| -rw-r--r-- | arch/x86/kernel/ptrace.c | 16 | ||||
| -rw-r--r-- | arch/x86/power/cpu_32.c | 8 | ||||
| -rw-r--r-- | arch/x86/power/cpu_64.c | 8 | ||||
| -rw-r--r-- | include/asm-generic/hw_breakpoint.h | 139 |
9 files changed, 255 insertions, 32 deletions
diff --git a/arch/x86/include/asm/a.out-core.h b/arch/x86/include/asm/a.out-core.h index bb70e39..fc4685d 100644 --- a/arch/x86/include/asm/a.out-core.h +++ b/arch/x86/include/asm/a.out-core.h @@ -32,10 +32,10 @@ static inline void aout_dump_thread(struct pt_regs *regs, struct user *dump) >> PAGE_SHIFT; dump->u_dsize -= dump->u_tsize; dump->u_ssize = 0; - dump->u_debugreg[0] = current->thread.debugreg0; - dump->u_debugreg[1] = current->thread.debugreg1; - dump->u_debugreg[2] = current->thread.debugreg2; - dump->u_debugreg[3] = current->thread.debugreg3; + dump->u_debugreg[0] = current->thread.debugreg[0]; + dump->u_debugreg[1] = current->thread.debugreg[1]; + dump->u_debugreg[2] = current->thread.debugreg[2]; + dump->u_debugreg[3] = current->thread.debugreg[3]; dump->u_debugreg[4] = 0; dump->u_debugreg[5] = 0; dump->u_debugreg[6] = current->thread.debugreg6; diff --git a/arch/x86/include/asm/debugreg.h b/arch/x86/include/asm/debugreg.h index 3ea6f37..23439fb 100644 --- a/arch/x86/include/asm/debugreg.h +++ b/arch/x86/include/asm/debugreg.h @@ -18,6 +18,7 @@ #define DR_TRAP1 (0x2) /* db1 */ #define DR_TRAP2 (0x4) /* db2 */ #define DR_TRAP3 (0x8) /* db3 */ +#define DR_TRAP_BITS (DR_TRAP0|DR_TRAP1|DR_TRAP2|DR_TRAP3) #define DR_STEP (0x4000) /* single-step */ #define DR_SWITCH (0x8000) /* task switch */ @@ -49,6 +50,8 @@ #define DR_LOCAL_ENABLE_SHIFT 0 /* Extra shift to the local enable bit */ #define DR_GLOBAL_ENABLE_SHIFT 1 /* Extra shift to the global enable bit */ +#define DR_LOCAL_ENABLE (0x1) /* Local enable for reg 0 */ +#define DR_GLOBAL_ENABLE (0x2) /* Global enable for reg 0 */ #define DR_ENABLE_SIZE 2 /* 2 enable bits per register */ #define DR_LOCAL_ENABLE_MASK (0x55) /* Set local bits for all 4 regs */ @@ -67,4 +70,30 @@ #define DR_LOCAL_SLOWDOWN (0x100) /* Local slow the pipeline */ #define DR_GLOBAL_SLOWDOWN (0x200) /* Global slow the pipeline */ +/* + * HW breakpoint additions + */ +#ifdef __KERNEL__ + +/* For process management */ +extern void flush_thread_hw_breakpoint(struct task_struct *tsk); +extern int copy_thread_hw_breakpoint(struct task_struct *tsk, + struct task_struct *child, unsigned long clone_flags); + +/* For CPU management */ +extern void load_debug_registers(void); +static inline void hw_breakpoint_disable(void) +{ + /* Zero the control register for HW Breakpoint */ + set_debugreg(0UL, 7); + + /* Zero-out the individual HW breakpoint address registers */ + set_debugreg(0UL, 0); + set_debugreg(0UL, 1); + set_debugreg(0UL, 2); + set_debugreg(0UL, 3); +} + +#endif /* __KERNEL__ */ + #endif /* _ASM_X86_DEBUGREG_H */ diff --git a/arch/x86/include/asm/hw_breakpoint.h b/arch/x86/include/asm/hw_breakpoint.h new file mode 100644 index 0000000..1acb4d4 --- /dev/null +++ b/arch/x86/include/asm/hw_breakpoint.h @@ -0,0 +1,55 @@ +#ifndef _I386_HW_BREAKPOINT_H +#define _I386_HW_BREAKPOINT_H + +#ifdef __KERNEL__ +#define __ARCH_HW_BREAKPOINT_H + +struct arch_hw_breakpoint { + char *name; /* Contains name of the symbol to set bkpt */ + unsigned long address; + u8 len; + u8 type; +}; + +#include <linux/kdebug.h> +#include <asm-generic/hw_breakpoint.h> + +/* Available HW breakpoint length encodings */ +#define HW_BREAKPOINT_LEN_1 0x40 +#define HW_BREAKPOINT_LEN_2 0x44 +#define HW_BREAKPOINT_LEN_4 0x4c +#define HW_BREAKPOINT_LEN_EXECUTE 0x40 + +#ifdef CONFIG_X86_64 +#define HW_BREAKPOINT_LEN_8 0x48 +#endif + +/* Available HW breakpoint type encodings */ + +/* trigger on instruction execute */ +#define HW_BREAKPOINT_EXECUTE 0x80 +/* trigger on memory write */ +#define HW_BREAKPOINT_WRITE 0x81 +/* trigger on memory read or write */ +#define HW_BREAKPOINT_RW 0x83 + +/* Total number of available HW breakpoint registers */ +#define HBP_NUM 4 + +extern struct hw_breakpoint *hbp_kernel[HBP_NUM]; +DECLARE_PER_CPU(struct hw_breakpoint*, this_hbp_kernel[HBP_NUM]); +extern unsigned int hbp_user_refcount[HBP_NUM]; + +extern void arch_install_thread_hw_breakpoint(struct task_struct *tsk); +extern void arch_uninstall_thread_hw_breakpoint(void); +extern int arch_check_va_in_userspace(unsigned long va, u8 hbp_len); +extern int arch_validate_hwbkpt_settings(struct hw_breakpoint *bp, + struct task_struct *tsk); +extern void arch_update_user_hw_breakpoint(int pos, struct task_struct *tsk); +extern void arch_flush_thread_hw_breakpoint(struct task_struct *tsk); +extern void arch_update_kernel_hw_breakpoint(void *); +extern int hw_breakpoint_exceptions_notify(struct notifier_block *unused, + unsigned long val, void *data); +#endif /* __KERNEL__ */ +#endif /* _I386_HW_BREAKPOINT_H */ + diff --git a/arch/x86/include/asm/processor.h b/arch/x86/include/asm/processor.h index 0b2fab0..448b34a 100644 --- a/arch/x86/include/asm/processor.h +++ b/arch/x86/include/asm/processor.h @@ -29,6 +29,7 @@ struct mm_struct; #include <linux/threads.h> #include <linux/init.h> +#define HBP_NUM 4 /* * Default implementation of macro that returns current * instruction pointer ("program counter"). @@ -431,12 +432,11 @@ struct thread_struct { unsigned long fs; unsigned long gs; /* Hardware debugging registers: */ - unsigned long debugreg0; - unsigned long debugreg1; - unsigned long debugreg2; - unsigned long debugreg3; + unsigned long debugreg[HBP_NUM]; unsigned long debugreg6; unsigned long debugreg7; + /* Hardware breakpoint info */ + struct hw_breakpoint *hbp[HBP_NUM]; /* Fault info: */ unsigned long cr2; unsigned long trap_no; diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c index fb5dfb8..291527c 100644 --- a/arch/x86/kernel/process.c +++ b/arch/x86/kernel/process.c @@ -106,10 +106,10 @@ void flush_thread(void) clear_tsk_thread_flag(tsk, TIF_DEBUG); - tsk->thread.debugreg0 = 0; - tsk->thread.debugreg1 = 0; - tsk->thread.debugreg2 = 0; - tsk->thread.debugreg3 = 0; + tsk->thread.debugreg[0] = 0; + tsk->thread.debugreg[1] = 0; + tsk->thread.debugreg[2] = 0; + tsk->thread.debugreg[3] = 0; tsk->thread.debugreg6 = 0; tsk->thread.debugreg7 = 0; memset(tsk->thread.tls_array, 0, sizeof(tsk->thread.tls_array)); @@ -194,10 +194,10 @@ void __switch_to_xtra(struct task_struct *prev_p, struct task_struct *next_p, update_debugctlmsr(next->debugctlmsr); if (test_tsk_thread_flag(next_p, TIF_DEBUG)) { - set_debugreg(next->debugreg0, 0); - set_debugreg(next->debugreg1, 1); - set_debugreg(next->debugreg2, 2); - set_debugreg(next->debugreg3, 3); + set_debugreg(next->debugreg[0], 0); + set_debugreg(next->debugreg[1], 1); + set_debugreg(next->debugreg[2], 2); + set_debugreg(next->debugreg[3], 3); /* no 4 and 5 */ set_debugreg(next->debugreg6, 6); set_debugreg(next->debugreg7, 7); diff --git a/arch/x86/kernel/ptrace.c b/arch/x86/kernel/ptrace.c index 09ecbde..313be40 100644 --- a/arch/x86/kernel/ptrace.c +++ b/arch/x86/kernel/ptrace.c @@ -471,10 +471,10 @@ static int genregs_set(struct task_struct *target, static unsigned long ptrace_get_debugreg(struct task_struct *child, int n) { switch (n) { - case 0: return child->thread.debugreg0; - case 1: return child->thread.debugreg1; - case 2: return child->thread.debugreg2; - case 3: return child->thread.debugreg3; + case 0: return child->thread.debugreg[0]; + case 1: return child->thread.debugreg[1]; + case 2: return child->thread.debugreg[2]; + case 3: return child->thread.debugreg[3]; case 6: return child->thread.debugreg6; case 7: return child->thread.debugreg7; } @@ -493,10 +493,10 @@ static int ptrace_set_debugreg(struct task_struct *child, return -EIO; switch (n) { - case 0: child->thread.debugreg0 = data; break; - case 1: child->thread.debugreg1 = data; break; - case 2: child->thread.debugreg2 = data; break; - case 3: child->thread.debugreg3 = data; break; + case 0: child->thread.debugreg[0] = data; break; + case 1: child->thread.debugreg[1] = data; break; + case 2: child->thread.debugreg[2] = data; break; + case 3: child->thread.debugreg[3] = data; break; case 6: if ((data & ~0xffffffffUL) != 0) diff --git a/arch/x86/power/cpu_32.c b/arch/x86/power/cpu_32.c index ce702c5..5199139 100644 --- a/arch/x86/power/cpu_32.c +++ b/arch/x86/power/cpu_32.c @@ -84,10 +84,10 @@ static void fix_processor_context(void) * Now maybe reload the debug registers */ if (current->thread.debugreg7) { - set_debugreg(current->thread.debugreg0, 0); - set_debugreg(current->thread.debugreg1, 1); - set_debugreg(current->thread.debugreg2, 2); - set_debugreg(current->thread.debugreg3, 3); + set_debugreg(current->thread.debugreg[0], 0); + set_debugreg(current->thread.debugreg[1], 1); + set_debugreg(current->thread.debugreg[2], 2); + set_debugreg(current->thread.debugreg[3], 3); /* no 4 and 5 */ set_debugreg(current->thread.debugreg6, 6); set_debugreg(current->thread.debugreg7, 7); diff --git a/arch/x86/power/cpu_64.c b/arch/x86/power/cpu_64.c index 5343540..1e3bdcc 100644 --- a/arch/x86/power/cpu_64.c +++ b/arch/x86/power/cpu_64.c @@ -163,10 +163,10 @@ static void fix_processor_context(void) * Now maybe reload the debug registers */ if (current->thread.debugreg7){ - loaddebug(¤t->thread, 0); - loaddebug(¤t->thread, 1); - loaddebug(¤t->thread, 2); - loaddebug(¤t->thread, 3); + set_debugreg(current->thread.debugreg[0], 0); + set_debugreg(current->thread.debugreg[1], 1); + set_debugreg(current->thread.debugreg[2], 2); + set_debugreg(current->thread.debugreg[3], 3); /* no 4 and 5 */ loaddebug(¤t->thread, 6); loaddebug(¤t->thread, 7); diff --git a/include/asm-generic/hw_breakpoint.h b/include/asm-generic/hw_breakpoint.h new file mode 100644 index 0000000..9bf2d12 --- /dev/null +++ b/include/asm-generic/hw_breakpoint.h @@ -0,0 +1,139 @@ +#ifndef _ASM_GENERIC_HW_BREAKPOINT_H +#define _ASM_GENERIC_HW_BREAKPOINT_H + +#ifndef __ARCH_HW_BREAKPOINT_H +#error "Please don't include this file directly" +#endif + +#ifdef __KERNEL__ +#include <linux/list.h> +#include <linux/types.h> +#include <linux/kallsyms.h> + +/** + * struct hw_breakpoint - unified kernel/user-space hardware breakpoint + * @triggered: callback invoked after target address access + * @info: arch-specific breakpoint info (address, length, and type) + * + * %hw_breakpoint structures are the kernel's way of representing + * hardware breakpoints. These are data breakpoints + * (also known as "watchpoints", triggered on data access), and the breakpoint's + * target address can be located in either kernel space or user space. + * + * The breakpoint's address, length, and type are highly + * architecture-specific. The values are encoded in the @info field; you + * specify them when registering the breakpoint. To examine the encoded + * values use hw_breakpoint_get_{kaddress,uaddress,len,type}(), declared + * below. + * + * The address is specified as a regular kernel pointer (for kernel-space + * breakponts) or as an %__user pointer (for user-space breakpoints). + * With register_user_hw_breakpoint(), the address must refer to a + * location in user space. The breakpoint will be active only while the + * requested task is running. Conversely with + * register_kernel_hw_breakpoint(), the address must refer to a location + * in kernel space, and the breakpoint will be active on all CPUs + * regardless of the current task. + * + * The length is the breakpoint's extent in bytes, which is subject to + * certain limitations. include/asm/hw_breakpoint.h contains macros + * defining the available lengths for a specific architecture. Note that + * the address's alignment must match the length. The breakpoint will + * catch accesses to any byte in the range from address to address + + * (length - 1). + * + * The breakpoint's type indicates the sort of access that will cause it + * to trigger. Possible values may include: + * + * %HW_BREAKPOINT_RW (triggered on read or write access), + * %HW_BREAKPOINT_WRITE (triggered on write access), and + * %HW_BREAKPOINT_READ (triggered on read access). + * + * Appropriate macros are defined in include/asm/hw_breakpoint.h; not all + * possibilities are available on all architectures. Execute breakpoints + * must have length equal to the special value %HW_BREAKPOINT_LEN_EXECUTE. + * + * When a breakpoint gets hit, the @triggered callback is + * invoked in_interrupt with a pointer to the %hw_breakpoint structure and the + * processor registers. + * Data breakpoints occur after the memory access has taken place. + * Breakpoints are disabled during execution @triggered, to avoid + * recursive traps and allow unhindered access to breakpointed memory. + * + * This sample code sets a breakpoint on pid_max and registers a callback + * function for writes to that variable. Note that it is not portable + * as written, because not all architectures support HW_BREAKPOINT_LEN_4. + * + * ---------------------------------------------------------------------- + * + * #include <asm/hw_breakpoint.h> + * + * struct hw_breakpoint my_bp; + * + * static void my_triggered(struct hw_breakpoint *bp, struct pt_regs *regs) + * { + * printk(KERN_DEBUG "Inside triggered routine of breakpoint exception\n"); + * dump_stack(); + * .......<more debugging output>........ + * } + * + * static struct hw_breakpoint my_bp; + * + * static int init_module(void) + * { + * ..........<do anything>............ + * my_bp.info.type = HW_BREAKPOINT_WRITE; + * my_bp.info.len = HW_BREAKPOINT_LEN_4; + * + * my_bp.installed = (void *)my_bp_installed; + * + * rc = register_kernel_hw_breakpoint(&my_bp); + * ..........<do anything>............ + * } + * + * static void cleanup_module(void) + * { + * ..........<do anything>............ + * unregister_kernel_hw_breakpoint(&my_bp); + * ..........<do anything>............ + * } + * + * ---------------------------------------------------------------------- + */ +struct hw_breakpoint { + void (*triggered)(struct hw_breakpoint *, struct pt_regs *); + struct arch_hw_breakpoint info; +}; + +/* + * len and type values are defined in include/asm/hw_breakpoint.h. + * Available values vary according to the architecture. On i386 the + * possibilities are: + * + * HW_BREAKPOINT_LEN_1 + * HW_BREAKPOINT_LEN_2 + * HW_BREAKPOINT_LEN_4 + * HW_BREAKPOINT_RW + * HW_BREAKPOINT_READ + * + * On other architectures HW_BREAKPOINT_LEN_8 may be available, and the + * 1-, 2-, and 4-byte lengths may be unavailable. There also may be + * HW_BREAKPOINT_WRITE. You can use #ifdef to check at compile time. + */ + +extern int register_user_hw_breakpoint(struct task_struct *tsk, + struct hw_breakpoint *bp); +extern int modify_user_hw_breakpoint(struct task_struct *tsk, + struct hw_breakpoint *bp); +extern void unregister_user_hw_breakpoint(struct task_struct *tsk, + struct hw_breakpoint *bp); +/* + * Kernel breakpoints are not associated with any particular thread. + */ +extern int register_kernel_hw_breakpoint(struct hw_breakpoint *bp); +extern void unregister_kernel_hw_breakpoint(struct hw_breakpoint *bp); + +extern unsigned int hbp_kernel_pos; + +#endif /* __KERNEL__ */ +#endif /* _ASM_GENERIC_HW_BREAKPOINT_H */ |
