40f9249a73
Clear the reserved bits from the stored copy of debug status register (DR6). This will help easy bitwise operations such as quick testing of a debug event origin. Signed-off-by: K.Prasad <prasad@linux.vnet.ibm.com> Cc: Roland McGrath <roland@redhat.com> Cc: Jan Kiszka <jan.kiszka@siemens.com> Cc: Alan Stern <stern@rowland.harvard.edu> Cc: Ingo Molnar <mingo@elte.hu> LKML-Reference: <20100128111401.GB13935@in.ibm.com> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
107 lines
3.7 KiB
C
107 lines
3.7 KiB
C
#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__
|
|
|
|
DECLARE_PER_CPU(unsigned long, cpu_dr7);
|
|
|
|
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 __get_cpu_var(cpu_dr7) & DR_GLOBAL_ENABLE_MASK;
|
|
}
|
|
|
|
extern void aout_dump_debugregs(struct user *dump);
|
|
|
|
extern void hw_breakpoint_restore(void);
|
|
|
|
#endif /* __KERNEL__ */
|
|
|
|
#endif /* _ASM_X86_DEBUGREG_H */
|