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author | Srikant Patnaik | 2015-01-11 12:28:04 +0530 |
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committer | Srikant Patnaik | 2015-01-11 12:28:04 +0530 |
commit | 871480933a1c28f8a9fed4c4d34d06c439a7a422 (patch) | |
tree | 8718f573808810c2a1e8cb8fb6ac469093ca2784 /arch/x86/include/asm/debugreg.h | |
parent | 9d40ac5867b9aefe0722bc1f110b965ff294d30d (diff) | |
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Moved, renamed, and deleted files
The original directory structure was scattered and unorganized.
Changes are basically to make it look like kernel structure.
Diffstat (limited to 'arch/x86/include/asm/debugreg.h')
-rw-r--r-- | arch/x86/include/asm/debugreg.h | 195 |
1 files changed, 195 insertions, 0 deletions
diff --git a/arch/x86/include/asm/debugreg.h b/arch/x86/include/asm/debugreg.h new file mode 100644 index 00000000..2d91580b --- /dev/null +++ b/arch/x86/include/asm/debugreg.h @@ -0,0 +1,195 @@ +#ifndef _ASM_X86_DEBUGREG_H +#define _ASM_X86_DEBUGREG_H + + +/* Indicate the register numbers for a number of the specific + debug registers. Registers 0-3 contain the addresses we wish to trap on */ +#define DR_FIRSTADDR 0 /* u_debugreg[DR_FIRSTADDR] */ +#define DR_LASTADDR 3 /* u_debugreg[DR_LASTADDR] */ + +#define DR_STATUS 6 /* u_debugreg[DR_STATUS] */ +#define DR_CONTROL 7 /* u_debugreg[DR_CONTROL] */ + +/* Define a few things for the status register. We can use this to determine + which debugging register was responsible for the trap. The other bits + are either reserved or not of interest to us. */ + +/* Define reserved bits in DR6 which are always set to 1 */ +#define DR6_RESERVED (0xFFFF0FF0) + +#define DR_TRAP0 (0x1) /* db0 */ +#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 */ + +/* Now define a bunch of things for manipulating the control register. + The top two bytes of the control register consist of 4 fields of 4 + bits - each field corresponds to one of the four debug registers, + and indicates what types of access we trap on, and how large the data + field is that we are looking at */ + +#define DR_CONTROL_SHIFT 16 /* Skip this many bits in ctl register */ +#define DR_CONTROL_SIZE 4 /* 4 control bits per register */ + +#define DR_RW_EXECUTE (0x0) /* Settings for the access types to trap on */ +#define DR_RW_WRITE (0x1) +#define DR_RW_READ (0x3) + +#define DR_LEN_1 (0x0) /* Settings for data length to trap on */ +#define DR_LEN_2 (0x4) +#define DR_LEN_4 (0xC) +#define DR_LEN_8 (0x8) + +/* The low byte to the control register determine which registers are + enabled. There are 4 fields of two bits. One bit is "local", meaning + that the processor will reset the bit after a task switch and the other + is global meaning that we have to explicitly reset the bit. With linux, + you can use either one, since we explicitly zero the register when we enter + kernel mode. */ + +#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 */ +#define DR_GLOBAL_ENABLE_MASK (0xAA) /* Set global bits for all 4 regs */ + +/* The second byte to the control register has a few special things. + We can slow the instruction pipeline for instructions coming via the + gdt or the ldt if we want to. I am not sure why this is an advantage */ + +#ifdef __i386__ +#define DR_CONTROL_RESERVED (0xFC00) /* Reserved by Intel */ +#else +#define DR_CONTROL_RESERVED (0xFFFFFFFF0000FC00UL) /* Reserved */ +#endif + +#define DR_LOCAL_SLOWDOWN (0x100) /* Local slow the pipeline */ +#define DR_GLOBAL_SLOWDOWN (0x200) /* Global slow the pipeline */ + +/* + * HW breakpoint additions + */ +#ifdef __KERNEL__ + +#include <linux/bug.h> + +DECLARE_PER_CPU(unsigned long, cpu_dr7); + +#ifndef CONFIG_PARAVIRT +/* + * These special macros can be used to get or set a debugging register + */ +#define get_debugreg(var, register) \ + (var) = native_get_debugreg(register) +#define set_debugreg(value, register) \ + native_set_debugreg(register, value) +#endif + +static inline unsigned long native_get_debugreg(int regno) +{ + unsigned long val = 0; /* Damn you, gcc! */ + + switch (regno) { + case 0: + asm("mov %%db0, %0" :"=r" (val)); + break; + case 1: + asm("mov %%db1, %0" :"=r" (val)); + break; + case 2: + asm("mov %%db2, %0" :"=r" (val)); + break; + case 3: + asm("mov %%db3, %0" :"=r" (val)); + break; + case 6: + asm("mov %%db6, %0" :"=r" (val)); + break; + case 7: + asm("mov %%db7, %0" :"=r" (val)); + break; + default: + BUG(); + } + return val; +} + +static inline void native_set_debugreg(int regno, unsigned long value) +{ + switch (regno) { + case 0: + asm("mov %0, %%db0" ::"r" (value)); + break; + case 1: + asm("mov %0, %%db1" ::"r" (value)); + break; + case 2: + asm("mov %0, %%db2" ::"r" (value)); + break; + case 3: + asm("mov %0, %%db3" ::"r" (value)); + break; + case 6: + asm("mov %0, %%db6" ::"r" (value)); + break; + case 7: + asm("mov %0, %%db7" ::"r" (value)); + break; + default: + BUG(); + } +} + +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); +} + +static inline int hw_breakpoint_active(void) +{ + return __this_cpu_read(cpu_dr7) & DR_GLOBAL_ENABLE_MASK; +} + +extern void aout_dump_debugregs(struct user *dump); + +extern void hw_breakpoint_restore(void); + +#ifdef CONFIG_X86_64 +DECLARE_PER_CPU(int, debug_stack_usage); +static inline void debug_stack_usage_inc(void) +{ + __get_cpu_var(debug_stack_usage)++; +} +static inline void debug_stack_usage_dec(void) +{ + __get_cpu_var(debug_stack_usage)--; +} +int is_debug_stack(unsigned long addr); +void debug_stack_set_zero(void); +void debug_stack_reset(void); +#else /* !X86_64 */ +static inline int is_debug_stack(unsigned long addr) { return 0; } +static inline void debug_stack_set_zero(void) { } +static inline void debug_stack_reset(void) { } +static inline void debug_stack_usage_inc(void) { } +static inline void debug_stack_usage_dec(void) { } +#endif /* X86_64 */ + + +#endif /* __KERNEL__ */ + +#endif /* _ASM_X86_DEBUGREG_H */ |