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git.proxmox.com Git - mirror_ubuntu-focal-kernel.git/blob - arch/alpha/kernel/ptrace.c
2 /* By Ross Biro 1/23/92 */
3 /* edited by Linus Torvalds */
4 /* mangled further by Bob Manson (manson@santafe.edu) */
5 /* more mutilation by David Mosberger (davidm@azstarnet.com) */
7 #include <linux/kernel.h>
8 #include <linux/sched.h>
9 #include <linux/sched/task_stack.h>
11 #include <linux/smp.h>
12 #include <linux/errno.h>
13 #include <linux/ptrace.h>
14 #include <linux/user.h>
15 #include <linux/security.h>
16 #include <linux/signal.h>
17 #include <linux/tracehook.h>
18 #include <linux/audit.h>
20 #include <linux/uaccess.h>
21 #include <asm/pgtable.h>
35 #define DBG(fac,args) {if ((fac) & DEBUG) printk args;}
40 #define BREAKINST 0x00000080 /* call_pal bpt */
43 * does not yet catch signals sent when the child dies.
44 * in exit.c or in signal.c.
48 * Processes always block with the following stack-layout:
50 * +================================+ <---- task + 2*PAGE_SIZE
51 * | PALcode saved frame (ps, pc, | ^
52 * | gp, a0, a1, a2) | |
53 * +================================+ | struct pt_regs
55 * | frame generated by SAVE_ALL | |
57 * +================================+
59 * | frame saved by do_switch_stack | | struct switch_stack
61 * +================================+
65 * The following table maps a register index into the stack offset at
66 * which the register is saved. Register indices are 0-31 for integer
67 * regs, 32-63 for fp regs, and 64 for the pc. Notice that sp and
68 * zero have no stack-slot and need to be treated specially (see
69 * get_reg/put_reg below).
72 REG_R0
= 0, REG_F0
= 32, REG_FPCR
= 63, REG_PC
= 64
76 (PAGE_SIZE*2 - sizeof(struct pt_regs) + offsetof(struct pt_regs, reg))
79 (PAGE_SIZE*2 - sizeof(struct pt_regs) - sizeof(struct switch_stack) \
80 + offsetof(struct switch_stack, reg))
82 static int regoff
[] = {
83 PT_REG( r0
), PT_REG( r1
), PT_REG( r2
), PT_REG( r3
),
84 PT_REG( r4
), PT_REG( r5
), PT_REG( r6
), PT_REG( r7
),
85 PT_REG( r8
), SW_REG( r9
), SW_REG( r10
), SW_REG( r11
),
86 SW_REG( r12
), SW_REG( r13
), SW_REG( r14
), SW_REG( r15
),
87 PT_REG( r16
), PT_REG( r17
), PT_REG( r18
), PT_REG( r19
),
88 PT_REG( r20
), PT_REG( r21
), PT_REG( r22
), PT_REG( r23
),
89 PT_REG( r24
), PT_REG( r25
), PT_REG( r26
), PT_REG( r27
),
90 PT_REG( r28
), PT_REG( gp
), -1, -1,
91 SW_REG(fp
[ 0]), SW_REG(fp
[ 1]), SW_REG(fp
[ 2]), SW_REG(fp
[ 3]),
92 SW_REG(fp
[ 4]), SW_REG(fp
[ 5]), SW_REG(fp
[ 6]), SW_REG(fp
[ 7]),
93 SW_REG(fp
[ 8]), SW_REG(fp
[ 9]), SW_REG(fp
[10]), SW_REG(fp
[11]),
94 SW_REG(fp
[12]), SW_REG(fp
[13]), SW_REG(fp
[14]), SW_REG(fp
[15]),
95 SW_REG(fp
[16]), SW_REG(fp
[17]), SW_REG(fp
[18]), SW_REG(fp
[19]),
96 SW_REG(fp
[20]), SW_REG(fp
[21]), SW_REG(fp
[22]), SW_REG(fp
[23]),
97 SW_REG(fp
[24]), SW_REG(fp
[25]), SW_REG(fp
[26]), SW_REG(fp
[27]),
98 SW_REG(fp
[28]), SW_REG(fp
[29]), SW_REG(fp
[30]), SW_REG(fp
[31]),
102 static unsigned long zero
;
105 * Get address of register REGNO in task TASK.
107 static unsigned long *
108 get_reg_addr(struct task_struct
* task
, unsigned long regno
)
113 addr
= &task_thread_info(task
)->pcb
.usp
;
114 } else if (regno
== 65) {
115 addr
= &task_thread_info(task
)->pcb
.unique
;
116 } else if (regno
== 31 || regno
> 65) {
120 addr
= task_stack_page(task
) + regoff
[regno
];
126 * Get contents of register REGNO in task TASK.
129 get_reg(struct task_struct
* task
, unsigned long regno
)
131 /* Special hack for fpcr -- combine hardware and software bits. */
133 unsigned long fpcr
= *get_reg_addr(task
, regno
);
135 = task_thread_info(task
)->ieee_state
& IEEE_SW_MASK
;
136 swcr
= swcr_update_status(swcr
, fpcr
);
139 return *get_reg_addr(task
, regno
);
143 * Write contents of register REGNO in task TASK.
146 put_reg(struct task_struct
*task
, unsigned long regno
, unsigned long data
)
149 task_thread_info(task
)->ieee_state
150 = ((task_thread_info(task
)->ieee_state
& ~IEEE_SW_MASK
)
151 | (data
& IEEE_SW_MASK
));
152 data
= (data
& FPCR_DYN_MASK
) | ieee_swcr_to_fpcr(data
);
154 *get_reg_addr(task
, regno
) = data
;
159 read_int(struct task_struct
*task
, unsigned long addr
, int * data
)
161 int copied
= access_process_vm(task
, addr
, data
, sizeof(int),
163 return (copied
== sizeof(int)) ? 0 : -EIO
;
167 write_int(struct task_struct
*task
, unsigned long addr
, int data
)
169 int copied
= access_process_vm(task
, addr
, &data
, sizeof(int),
170 FOLL_FORCE
| FOLL_WRITE
);
171 return (copied
== sizeof(int)) ? 0 : -EIO
;
178 ptrace_set_bpt(struct task_struct
* child
)
180 int displ
, i
, res
, reg_b
, nsaved
= 0;
181 unsigned int insn
, op_code
;
184 pc
= get_reg(child
, REG_PC
);
185 res
= read_int(child
, pc
, (int *) &insn
);
189 op_code
= insn
>> 26;
190 if (op_code
>= 0x30) {
192 * It's a branch: instead of trying to figure out
193 * whether the branch will be taken or not, we'll put
194 * a breakpoint at either location. This is simpler,
195 * more reliable, and probably not a whole lot slower
196 * than the alternative approach of emulating the
197 * branch (emulation can be tricky for fp branches).
199 displ
= ((s32
)(insn
<< 11)) >> 9;
200 task_thread_info(child
)->bpt_addr
[nsaved
++] = pc
+ 4;
201 if (displ
) /* guard against unoptimized code */
202 task_thread_info(child
)->bpt_addr
[nsaved
++]
204 DBG(DBG_BPT
, ("execing branch\n"));
205 } else if (op_code
== 0x1a) {
206 reg_b
= (insn
>> 16) & 0x1f;
207 task_thread_info(child
)->bpt_addr
[nsaved
++] = get_reg(child
, reg_b
);
208 DBG(DBG_BPT
, ("execing jump\n"));
210 task_thread_info(child
)->bpt_addr
[nsaved
++] = pc
+ 4;
211 DBG(DBG_BPT
, ("execing normal insn\n"));
214 /* install breakpoints: */
215 for (i
= 0; i
< nsaved
; ++i
) {
216 res
= read_int(child
, task_thread_info(child
)->bpt_addr
[i
],
220 task_thread_info(child
)->bpt_insn
[i
] = insn
;
221 DBG(DBG_BPT
, (" -> next_pc=%lx\n",
222 task_thread_info(child
)->bpt_addr
[i
]));
223 res
= write_int(child
, task_thread_info(child
)->bpt_addr
[i
],
228 task_thread_info(child
)->bpt_nsaved
= nsaved
;
233 * Ensure no single-step breakpoint is pending. Returns non-zero
234 * value if child was being single-stepped.
237 ptrace_cancel_bpt(struct task_struct
* child
)
239 int i
, nsaved
= task_thread_info(child
)->bpt_nsaved
;
241 task_thread_info(child
)->bpt_nsaved
= 0;
244 printk("ptrace_cancel_bpt: bogus nsaved: %d!\n", nsaved
);
248 for (i
= 0; i
< nsaved
; ++i
) {
249 write_int(child
, task_thread_info(child
)->bpt_addr
[i
],
250 task_thread_info(child
)->bpt_insn
[i
]);
252 return (nsaved
!= 0);
255 void user_enable_single_step(struct task_struct
*child
)
257 /* Mark single stepping. */
258 task_thread_info(child
)->bpt_nsaved
= -1;
261 void user_disable_single_step(struct task_struct
*child
)
263 ptrace_cancel_bpt(child
);
267 * Called by kernel/ptrace.c when detaching..
269 * Make sure the single step bit is not set.
271 void ptrace_disable(struct task_struct
*child
)
273 user_disable_single_step(child
);
276 long arch_ptrace(struct task_struct
*child
, long request
,
277 unsigned long addr
, unsigned long data
)
284 /* When I and D space are separate, these will need to be fixed. */
285 case PTRACE_PEEKTEXT
: /* read word at location addr. */
286 case PTRACE_PEEKDATA
:
287 copied
= ptrace_access_vm(child
, addr
, &tmp
, sizeof(tmp
),
290 if (copied
!= sizeof(tmp
))
293 force_successful_syscall_return();
297 /* Read register number ADDR. */
299 force_successful_syscall_return();
300 ret
= get_reg(child
, addr
);
301 DBG(DBG_MEM
, ("peek $%lu->%#lx\n", addr
, ret
));
304 /* When I and D space are separate, this will have to be fixed. */
305 case PTRACE_POKETEXT
: /* write the word at location addr. */
306 case PTRACE_POKEDATA
:
307 ret
= generic_ptrace_pokedata(child
, addr
, data
);
310 case PTRACE_POKEUSR
: /* write the specified register */
311 DBG(DBG_MEM
, ("poke $%lu<-%#lx\n", addr
, data
));
312 ret
= put_reg(child
, addr
, data
);
315 ret
= ptrace_request(child
, request
, addr
, data
);
321 asmlinkage
unsigned long syscall_trace_enter(void)
323 unsigned long ret
= 0;
324 struct pt_regs
*regs
= current_pt_regs();
325 if (test_thread_flag(TIF_SYSCALL_TRACE
) &&
326 tracehook_report_syscall_entry(current_pt_regs()))
328 audit_syscall_entry(regs
->r0
, regs
->r16
, regs
->r17
, regs
->r18
, regs
->r19
);
329 return ret
?: current_pt_regs()->r0
;
333 syscall_trace_leave(void)
335 audit_syscall_exit(current_pt_regs());
336 if (test_thread_flag(TIF_SYSCALL_TRACE
))
337 tracehook_report_syscall_exit(current_pt_regs(), 0);