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linux/include/asm-ia64/ptrace.h
Tony Luck 4dcc29e157 [IA64] Workaround for RSE issue 
Problem: An application violating the architectural rules regarding
operation dependencies and having specific Register Stack Engine (RSE)
state at the time of the violation, may result in an illegal operation
fault and invalid RSE state.  Such faults may initiate a cascade of
repeated illegal operation faults within OS interruption handlers.
The specific behavior is OS dependent.

Implication: An application causing an illegal operation fault with
specific RSE state may result in a series of illegal operation faults
and an eventual OS stack overflow condition.

Workaround: OS interruption handlers that switch to kernel backing
store implement a check for invalid RSE state to avoid the series
of illegal operation faults.

The core of the workaround is the RSE_WORKAROUND code sequence
inserted into each invocation of the SAVE_MIN_WITH_COVER and
SAVE_MIN_WITH_COVER_R19 macros.  This sequence includes hard-coded
constants that depend on the number of stacked physical registers
being 96.  The rest of this patch consists of code to disable this
workaround should this not be the case (with the presumption that
if a future Itanium processor increases the number of registers, it
would also remove the need for this patch).

Move the start of the RBS up to a mod32 boundary to avoid some
corner cases.

The dispatch_illegal_op_fault code outgrew the spot it was
squatting in when built with this patch and CONFIG_VIRT_CPU_ACCOUNTING=y
Move it out to the end of the ivt.

Signed-off-by: Tony Luck <tony.luck@intel.com>
2008-05-27 13:24:39 -07:00

364 lines
13 KiB
C
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#ifndef _ASM_IA64_PTRACE_H
#define _ASM_IA64_PTRACE_H
/*
* Copyright (C) 1998-2004 Hewlett-Packard Co
* David Mosberger-Tang <davidm@hpl.hp.com>
* Stephane Eranian <eranian@hpl.hp.com>
* Copyright (C) 2003 Intel Co
* Suresh Siddha <suresh.b.siddha@intel.com>
* Fenghua Yu <fenghua.yu@intel.com>
* Arun Sharma <arun.sharma@intel.com>
*
* 12/07/98 S. Eranian added pt_regs & switch_stack
* 12/21/98 D. Mosberger updated to match latest code
* 6/17/99 D. Mosberger added second unat member to "struct switch_stack"
*
*/
/*
* When a user process is blocked, its state looks as follows:
*
* +----------------------+ ------- IA64_STK_OFFSET
* | | ^
* | struct pt_regs | |
* | | |
* +----------------------+ |
* | | |
* | memory stack | |
* | (growing downwards) | |
* //.....................// |
* |
* //.....................// |
* | | |
* +----------------------+ |
* | struct switch_stack | |
* | | |
* +----------------------+ |
* | | |
* //.....................// |
* |
* //.....................// |
* | | |
* | register stack | |
* | (growing upwards) | |
* | | |
* +----------------------+ | --- IA64_RBS_OFFSET
* | struct thread_info | | ^
* +----------------------+ | |
* | | | |
* | struct task_struct | | |
* current -> | | | |
* +----------------------+ -------
*
* Note that ar.ec is not saved explicitly in pt_reg or switch_stack.
* This is because ar.ec is saved as part of ar.pfs.
*/
#include <asm/fpu.h>
#ifdef __KERNEL__
#ifndef ASM_OFFSETS_C
#include <asm/asm-offsets.h>
#endif
/*
* Base-2 logarithm of number of pages to allocate per task structure
* (including register backing store and memory stack):
*/
#if defined(CONFIG_IA64_PAGE_SIZE_4KB)
# define KERNEL_STACK_SIZE_ORDER 3
#elif defined(CONFIG_IA64_PAGE_SIZE_8KB)
# define KERNEL_STACK_SIZE_ORDER 2
#elif defined(CONFIG_IA64_PAGE_SIZE_16KB)
# define KERNEL_STACK_SIZE_ORDER 1
#else
# define KERNEL_STACK_SIZE_ORDER 0
#endif
#define IA64_RBS_OFFSET ((IA64_TASK_SIZE + IA64_THREAD_INFO_SIZE + 31) & ~31)
#define IA64_STK_OFFSET ((1 << KERNEL_STACK_SIZE_ORDER)*PAGE_SIZE)
#define KERNEL_STACK_SIZE IA64_STK_OFFSET
#endif /* __KERNEL__ */
#ifndef __ASSEMBLY__
/*
* This struct defines the way the registers are saved on system
* calls.
*
* We don't save all floating point register because the kernel
* is compiled to use only a very small subset, so the other are
* untouched.
*
* THIS STRUCTURE MUST BE A MULTIPLE 16-BYTE IN SIZE
* (because the memory stack pointer MUST ALWAYS be aligned this way)
*
*/
struct pt_regs {
/* The following registers are saved by SAVE_MIN: */
unsigned long b6; /* scratch */
unsigned long b7; /* scratch */
unsigned long ar_csd; /* used by cmp8xchg16 (scratch) */
unsigned long ar_ssd; /* reserved for future use (scratch) */
unsigned long r8; /* scratch (return value register 0) */
unsigned long r9; /* scratch (return value register 1) */
unsigned long r10; /* scratch (return value register 2) */
unsigned long r11; /* scratch (return value register 3) */
unsigned long cr_ipsr; /* interrupted task's psr */
unsigned long cr_iip; /* interrupted task's instruction pointer */
/*
* interrupted task's function state; if bit 63 is cleared, it
* contains syscall's ar.pfs.pfm:
*/
unsigned long cr_ifs;
unsigned long ar_unat; /* interrupted task's NaT register (preserved) */
unsigned long ar_pfs; /* prev function state */
unsigned long ar_rsc; /* RSE configuration */
/* The following two are valid only if cr_ipsr.cpl > 0 || ti->flags & _TIF_MCA_INIT */
unsigned long ar_rnat; /* RSE NaT */
unsigned long ar_bspstore; /* RSE bspstore */
unsigned long pr; /* 64 predicate registers (1 bit each) */
unsigned long b0; /* return pointer (bp) */
unsigned long loadrs; /* size of dirty partition << 16 */
unsigned long r1; /* the gp pointer */
unsigned long r12; /* interrupted task's memory stack pointer */
unsigned long r13; /* thread pointer */
unsigned long ar_fpsr; /* floating point status (preserved) */
unsigned long r15; /* scratch */
/* The remaining registers are NOT saved for system calls. */
unsigned long r14; /* scratch */
unsigned long r2; /* scratch */
unsigned long r3; /* scratch */
/* The following registers are saved by SAVE_REST: */
unsigned long r16; /* scratch */
unsigned long r17; /* scratch */
unsigned long r18; /* scratch */
unsigned long r19; /* scratch */
unsigned long r20; /* scratch */
unsigned long r21; /* scratch */
unsigned long r22; /* scratch */
unsigned long r23; /* scratch */
unsigned long r24; /* scratch */
unsigned long r25; /* scratch */
unsigned long r26; /* scratch */
unsigned long r27; /* scratch */
unsigned long r28; /* scratch */
unsigned long r29; /* scratch */
unsigned long r30; /* scratch */
unsigned long r31; /* scratch */
unsigned long ar_ccv; /* compare/exchange value (scratch) */
/*
* Floating point registers that the kernel considers scratch:
*/
struct ia64_fpreg f6; /* scratch */
struct ia64_fpreg f7; /* scratch */
struct ia64_fpreg f8; /* scratch */
struct ia64_fpreg f9; /* scratch */
struct ia64_fpreg f10; /* scratch */
struct ia64_fpreg f11; /* scratch */
};
/*
* This structure contains the addition registers that need to
* preserved across a context switch. This generally consists of
* "preserved" registers.
*/
struct switch_stack {
unsigned long caller_unat; /* user NaT collection register (preserved) */
unsigned long ar_fpsr; /* floating-point status register */
struct ia64_fpreg f2; /* preserved */
struct ia64_fpreg f3; /* preserved */
struct ia64_fpreg f4; /* preserved */
struct ia64_fpreg f5; /* preserved */
struct ia64_fpreg f12; /* scratch, but untouched by kernel */
struct ia64_fpreg f13; /* scratch, but untouched by kernel */
struct ia64_fpreg f14; /* scratch, but untouched by kernel */
struct ia64_fpreg f15; /* scratch, but untouched by kernel */
struct ia64_fpreg f16; /* preserved */
struct ia64_fpreg f17; /* preserved */
struct ia64_fpreg f18; /* preserved */
struct ia64_fpreg f19; /* preserved */
struct ia64_fpreg f20; /* preserved */
struct ia64_fpreg f21; /* preserved */
struct ia64_fpreg f22; /* preserved */
struct ia64_fpreg f23; /* preserved */
struct ia64_fpreg f24; /* preserved */
struct ia64_fpreg f25; /* preserved */
struct ia64_fpreg f26; /* preserved */
struct ia64_fpreg f27; /* preserved */
struct ia64_fpreg f28; /* preserved */
struct ia64_fpreg f29; /* preserved */
struct ia64_fpreg f30; /* preserved */
struct ia64_fpreg f31; /* preserved */
unsigned long r4; /* preserved */
unsigned long r5; /* preserved */
unsigned long r6; /* preserved */
unsigned long r7; /* preserved */
unsigned long b0; /* so we can force a direct return in copy_thread */
unsigned long b1;
unsigned long b2;
unsigned long b3;
unsigned long b4;
unsigned long b5;
unsigned long ar_pfs; /* previous function state */
unsigned long ar_lc; /* loop counter (preserved) */
unsigned long ar_unat; /* NaT bits for r4-r7 */
unsigned long ar_rnat; /* RSE NaT collection register */
unsigned long ar_bspstore; /* RSE dirty base (preserved) */
unsigned long pr; /* 64 predicate registers (1 bit each) */
};
#ifdef __KERNEL__
#include <asm/current.h>
#include <asm/page.h>
/*
* We use the ia64_psr(regs)->ri to determine which of the three
* instructions in bundle (16 bytes) took the sample. Generate
* the canonical representation by adding to instruction pointer.
*/
# define instruction_pointer(regs) ((regs)->cr_iip + ia64_psr(regs)->ri)
#define regs_return_value(regs) ((regs)->r8)
/* Conserve space in histogram by encoding slot bits in address
* bits 2 and 3 rather than bits 0 and 1.
*/
#define profile_pc(regs) \
({ \
unsigned long __ip = instruction_pointer(regs); \
(__ip & ~3UL) + ((__ip & 3UL) << 2); \
})
/* given a pointer to a task_struct, return the user's pt_regs */
# define task_pt_regs(t) (((struct pt_regs *) ((char *) (t) + IA64_STK_OFFSET)) - 1)
# define ia64_psr(regs) ((struct ia64_psr *) &(regs)->cr_ipsr)
# define user_mode(regs) (((struct ia64_psr *) &(regs)->cr_ipsr)->cpl != 0)
# define user_stack(task,regs) ((long) regs - (long) task == IA64_STK_OFFSET - sizeof(*regs))
# define fsys_mode(task,regs) \
({ \
struct task_struct *_task = (task); \
struct pt_regs *_regs = (regs); \
!user_mode(_regs) && user_stack(_task, _regs); \
})
/*
* System call handlers that, upon successful completion, need to return a negative value
* should call force_successful_syscall_return() right before returning. On architectures
* where the syscall convention provides for a separate error flag (e.g., alpha, ia64,
* ppc{,64}, sparc{,64}, possibly others), this macro can be used to ensure that the error
* flag will not get set. On architectures which do not support a separate error flag,
* the macro is a no-op and the spurious error condition needs to be filtered out by some
* other means (e.g., in user-level, by passing an extra argument to the syscall handler,
* or something along those lines).
*
* On ia64, we can clear the user's pt_regs->r8 to force a successful syscall.
*/
# define force_successful_syscall_return() (task_pt_regs(current)->r8 = 0)
struct task_struct; /* forward decl */
struct unw_frame_info; /* forward decl */
extern void show_regs (struct pt_regs *);
extern void ia64_do_show_stack (struct unw_frame_info *, void *);
extern unsigned long ia64_get_user_rbs_end (struct task_struct *, struct pt_regs *,
unsigned long *);
extern long ia64_peek (struct task_struct *, struct switch_stack *, unsigned long,
unsigned long, long *);
extern long ia64_poke (struct task_struct *, struct switch_stack *, unsigned long,
unsigned long, long);
extern void ia64_flush_fph (struct task_struct *);
extern void ia64_sync_fph (struct task_struct *);
extern void ia64_sync_krbs(void);
extern long ia64_sync_user_rbs (struct task_struct *, struct switch_stack *,
unsigned long, unsigned long);
/* get nat bits for scratch registers such that bit N==1 iff scratch register rN is a NaT */
extern unsigned long ia64_get_scratch_nat_bits (struct pt_regs *pt, unsigned long scratch_unat);
/* put nat bits for scratch registers such that scratch register rN is a NaT iff bit N==1 */
extern unsigned long ia64_put_scratch_nat_bits (struct pt_regs *pt, unsigned long nat);
extern void ia64_increment_ip (struct pt_regs *pt);
extern void ia64_decrement_ip (struct pt_regs *pt);
extern void ia64_ptrace_stop(void);
#define arch_ptrace_stop(code, info) \
ia64_ptrace_stop()
#define arch_ptrace_stop_needed(code, info) \
(!test_thread_flag(TIF_RESTORE_RSE))
extern void ptrace_attach_sync_user_rbs (struct task_struct *);
#define arch_ptrace_attach(child) \
ptrace_attach_sync_user_rbs(child)
#define arch_has_single_step() (1)
extern void user_enable_single_step(struct task_struct *);
extern void user_disable_single_step(struct task_struct *);
#define arch_has_block_step() (1)
extern void user_enable_block_step(struct task_struct *);
#endif /* !__KERNEL__ */
/* pt_all_user_regs is used for PTRACE_GETREGS PTRACE_SETREGS */
struct pt_all_user_regs {
unsigned long nat;
unsigned long cr_iip;
unsigned long cfm;
unsigned long cr_ipsr;
unsigned long pr;
unsigned long gr[32];
unsigned long br[8];
unsigned long ar[128];
struct ia64_fpreg fr[128];
};
#endif /* !__ASSEMBLY__ */
/* indices to application-registers array in pt_all_user_regs */
#define PT_AUR_RSC 16
#define PT_AUR_BSP 17
#define PT_AUR_BSPSTORE 18
#define PT_AUR_RNAT 19
#define PT_AUR_CCV 32
#define PT_AUR_UNAT 36
#define PT_AUR_FPSR 40
#define PT_AUR_PFS 64
#define PT_AUR_LC 65
#define PT_AUR_EC 66
/*
* The numbers chosen here are somewhat arbitrary but absolutely MUST
* not overlap with any of the number assigned in <linux/ptrace.h>.
*/
#define PTRACE_SINGLEBLOCK 12 /* resume execution until next branch */
#define PTRACE_OLD_GETSIGINFO 13 /* (replaced by PTRACE_GETSIGINFO in <linux/ptrace.h>) */
#define PTRACE_OLD_SETSIGINFO 14 /* (replaced by PTRACE_SETSIGINFO in <linux/ptrace.h>) */
#define PTRACE_GETREGS 18 /* get all registers (pt_all_user_regs) in one shot */
#define PTRACE_SETREGS 19 /* set all registers (pt_all_user_regs) in one shot */
#define PTRACE_OLDSETOPTIONS 21
#endif /* _ASM_IA64_PTRACE_H */
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