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sparc64:Support User Probes for sparc

Browse Source 
Signed-off-by: Eric Saint Etienne <eric.saint.etienne@oracle.com>
Signed-off-by: Allen Pais <allen.pais@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Allen Pais 2016-10-13 10:06:13 +05:30 committed by David S. Miller
parent 69973b8308
commit e8f4aa6087
14 changed files with 500 additions and 4 deletions
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1
arch/Kconfig
View File

@ -96,6 +96,7 @@ config KPROBES_ON_FTRACE
config UPROBES
def_bool n
depends on ARCH_SUPPORTS_UPROBES
help
Uprobes is the user-space counterpart to kprobes: they
enable instrumentation applications (such as 'perf probe')

3
arch/sparc/Kconfig
View File

@ -155,6 +155,9 @@ config PGTABLE_LEVELS
default 4 if 64BIT
default 3
config ARCH_SUPPORTS_UPROBES
def_bool y if SPARC64
source "init/Kconfig"
source "kernel/Kconfig.freezer"

1
arch/sparc/configs/sparc64_defconfig
View File

@ -213,6 +213,7 @@ CONFIG_SCHEDSTATS=y
# CONFIG_RCU_CPU_STALL_DETECTOR is not set
CONFIG_SYSCTL_SYSCALL_CHECK=y
CONFIG_BLK_DEV_IO_TRACE=y
CONFIG_UPROBE_EVENTS=y
CONFIG_KEYS=y
CONFIG_CRYPTO_NULL=m
CONFIG_CRYPTO_TEST=m

2
arch/sparc/include/asm/kdebug_64.h
View File

@ -10,6 +10,8 @@ enum die_val {
DIE_OOPS = 1,
DIE_DEBUG, /* ta 0x70 */
DIE_DEBUG_2, /* ta 0x71 */
DIE_BPT, /* ta 0x73 */
DIE_SSTEP, /* ta 0x74 */
DIE_DIE,
DIE_TRAP,
DIE_TRAP_TL1,

35
arch/sparc/include/asm/ptrace.h
View File

@ -61,7 +61,10 @@ extern union global_cpu_snapshot global_cpu_snapshot[NR_CPUS];
#define force_successful_syscall_return() set_thread_noerror(1)
#define user_mode(regs) (!((regs)->tstate & TSTATE_PRIV))
#define instruction_pointer(regs) ((regs)->tpc)
#define instruction_pointer_set(regs, val) ((regs)->tpc = (val))
#define instruction_pointer_set(regs, val) do { \
(regs)->tpc = (val); \
(regs)->tnpc = (val)+4; \
} while (0)
#define user_stack_pointer(regs) ((regs)->u_regs[UREG_FP])
static inline int is_syscall_success(struct pt_regs *regs)
{
@ -77,6 +80,36 @@ unsigned long profile_pc(struct pt_regs *);
#else
#define profile_pc(regs) instruction_pointer(regs)
#endif
#define MAX_REG_OFFSET (offsetof(struct pt_regs, magic))
extern int regs_query_register_offset(const char *name);
/**
* regs_get_register() - get register value from its offset
* @regs: pt_regs from which register value is gotten
* @offset: offset number of the register.
*
* regs_get_register returns the value of a register whose
* offset from @regs. The @offset is the offset of the register
* in struct pt_regs. If @offset is bigger than MAX_REG_OFFSET,
* this returns 0.
*/
static inline unsigned long regs_get_register(struct pt_regs *regs,
unsigned long offset)
{
if (unlikely(offset >= MAX_REG_OFFSET))
return 0;
if (offset == PT_V9_Y)
return *(unsigned int *)((unsigned long)regs + offset);
return *(unsigned long *)((unsigned long)regs + offset);
}
/* Valid only for Kernel mode traps. */
static inline unsigned long kernel_stack_pointer(struct pt_regs *regs)
{
return regs->u_regs[UREG_I6];
}
#else /* __ASSEMBLY__ */
#endif /* __ASSEMBLY__ */
#else /* (defined(__sparc__) && defined(__arch64__)) */

6
arch/sparc/include/asm/thread_info_64.h
View File

@ -180,7 +180,7 @@ register struct thread_info *current_thread_info_reg asm("g6");
#define TIF_NEED_RESCHED 3 /* rescheduling necessary */
/* flag bit 4 is available */
#define TIF_UNALIGNED 5 /* allowed to do unaligned accesses */
/* flag bit 6 is available */
#define TIF_UPROBE 6 /* breakpointed or singlestepped */
#define TIF_32BIT 7 /* 32-bit binary */
#define TIF_NOHZ 8 /* in adaptive nohz mode */
#define TIF_SECCOMP 9 /* secure computing */
@ -199,6 +199,7 @@ register struct thread_info *current_thread_info_reg asm("g6");
#define _TIF_SIGPENDING (1<<TIF_SIGPENDING)
#define _TIF_NEED_RESCHED (1<<TIF_NEED_RESCHED)
#define _TIF_UNALIGNED (1<<TIF_UNALIGNED)
#define _TIF_UPROBE (1<<TIF_UPROBE)
#define _TIF_32BIT (1<<TIF_32BIT)
#define _TIF_NOHZ (1<<TIF_NOHZ)
#define _TIF_SECCOMP (1<<TIF_SECCOMP)
@ -209,7 +210,8 @@ register struct thread_info *current_thread_info_reg asm("g6");
#define _TIF_USER_WORK_MASK ((0xff << TI_FLAG_WSAVED_SHIFT) | \
_TIF_DO_NOTIFY_RESUME_MASK | \
_TIF_NEED_RESCHED)
#define _TIF_DO_NOTIFY_RESUME_MASK (_TIF_NOTIFY_RESUME | _TIF_SIGPENDING)
#define _TIF_DO_NOTIFY_RESUME_MASK (_TIF_NOTIFY_RESUME | \
_TIF_SIGPENDING | _TIF_UPROBE)
#define is_32bit_task() (test_thread_flag(TIF_32BIT))

6
arch/sparc/include/asm/ttable.h
View File

@ -186,6 +186,12 @@
#define KPROBES_TRAP(lvl) TRAP_ARG(bad_trap, lvl)
#endif
#ifdef CONFIG_UPROBES
#define UPROBES_TRAP(lvl) TRAP_ARG(uprobe_trap, lvl)
#else
#define UPROBES_TRAP(lvl) TRAP_ARG(bad_trap, lvl)
#endif
#ifdef CONFIG_KGDB
#define KGDB_TRAP(lvl) TRAP_IRQ(kgdb_trap, lvl)
#else

59
arch/sparc/include/asm/uprobes.h Normal file
View File

@ -0,0 +1,59 @@
#ifndef _ASM_UPROBES_H
#define _ASM_UPROBES_H
/*
* 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>
*/
typedef u32 uprobe_opcode_t;
#define MAX_UINSN_BYTES 4
#define UPROBE_XOL_SLOT_BYTES (MAX_UINSN_BYTES * 2)
#define UPROBE_SWBP_INSN_SIZE 4
#define UPROBE_SWBP_INSN 0x91d02073 /* ta 0x73 */
#define UPROBE_STP_INSN 0x91d02074 /* ta 0x74 */
#define ANNUL_BIT (1 << 29)
struct arch_uprobe {
union {
u8 insn[MAX_UINSN_BYTES];
u32 ixol;
};
};
struct arch_uprobe_task {
u32 saved_tpc;
u32 saved_tnpc;
};
struct task_struct;
struct notifier_block;
extern int arch_uprobe_analyze_insn(struct arch_uprobe *aup, struct mm_struct *mm, unsigned long addr);
extern int arch_uprobe_pre_xol(struct arch_uprobe *aup, struct pt_regs *regs);
extern int arch_uprobe_post_xol(struct arch_uprobe *aup, struct pt_regs *regs);
extern bool arch_uprobe_xol_was_trapped(struct task_struct *tsk);
extern int arch_uprobe_exception_notify(struct notifier_block *self, unsigned long val, void *data);
extern void arch_uprobe_abort_xol(struct arch_uprobe *aup, struct pt_regs *regs);
#endif /* _ASM_UPROBES_H */

1
arch/sparc/kernel/Makefile
View File

@ -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

54
arch/sparc/kernel/ptrace_64.c
View File

@ -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;
}

2
arch/sparc/kernel/signal_64.c
View File

@ -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) {

2
arch/sparc/kernel/ttable_64.S
View File

@ -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)

331
arch/sparc/kernel/uprobes.c Normal file
View File

@ -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 = &regs->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 = &regs->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 = &current->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;
}

1
include/linux/uprobes.h
View File

@ -27,6 +27,7 @@
#include <linux/errno.h>
#include <linux/rbtree.h>
#include <linux/types.h>
#include <linux/wait.h>
struct vm_area_struct;
struct mm_struct;