2 * User-space Probes (UProbes) for s390
4 * Copyright IBM Corp. 2014
5 * Author(s): Jan Willeke,
8 #include <linux/kprobes.h>
9 #include <linux/uaccess.h>
10 #include <linux/uprobes.h>
11 #include <linux/compat.h>
12 #include <linux/kdebug.h>
13 #include <asm/switch_to.h>
14 #include <asm/facility.h>
18 #define UPROBE_TRAP_NR UINT_MAX
20 int arch_uprobe_analyze_insn(struct arch_uprobe *auprobe, struct mm_struct *mm,
23 return probe_is_prohibited_opcode(auprobe->insn);
26 int arch_uprobe_pre_xol(struct arch_uprobe *auprobe, struct pt_regs *regs)
28 if (psw_bits(regs->psw).eaba == PSW_AMODE_24BIT)
30 if (!is_compat_task() && psw_bits(regs->psw).eaba == PSW_AMODE_31BIT)
32 clear_pt_regs_flag(regs, PIF_PER_TRAP);
33 auprobe->saved_per = psw_bits(regs->psw).r;
34 auprobe->saved_int_code = regs->int_code;
35 regs->int_code = UPROBE_TRAP_NR;
36 regs->psw.addr = current->utask->xol_vaddr;
37 set_tsk_thread_flag(current, TIF_UPROBE_SINGLESTEP);
38 update_cr_regs(current);
42 bool arch_uprobe_xol_was_trapped(struct task_struct *tsk)
44 struct pt_regs *regs = task_pt_regs(tsk);
46 if (regs->int_code != UPROBE_TRAP_NR)
51 int arch_uprobe_post_xol(struct arch_uprobe *auprobe, struct pt_regs *regs)
53 int fixup = probe_get_fixup_type(auprobe->insn);
54 struct uprobe_task *utask = current->utask;
56 clear_tsk_thread_flag(current, TIF_UPROBE_SINGLESTEP);
57 update_cr_regs(current);
58 psw_bits(regs->psw).r = auprobe->saved_per;
59 regs->int_code = auprobe->saved_int_code;
61 if (fixup & FIXUP_PSW_NORMAL)
62 regs->psw.addr += utask->vaddr - utask->xol_vaddr;
63 if (fixup & FIXUP_RETURN_REGISTER) {
64 int reg = (auprobe->insn[0] & 0xf0) >> 4;
66 regs->gprs[reg] += utask->vaddr - utask->xol_vaddr;
68 if (fixup & FIXUP_BRANCH_NOT_TAKEN) {
69 int ilen = insn_length(auprobe->insn[0] >> 8);
71 if (regs->psw.addr - utask->xol_vaddr == ilen)
72 regs->psw.addr = utask->vaddr + ilen;
74 /* If per tracing was active generate trap */
75 if (regs->psw.mask & PSW_MASK_PER)
80 int arch_uprobe_exception_notify(struct notifier_block *self, unsigned long val,
83 struct die_args *args = data;
84 struct pt_regs *regs = args->regs;
88 if (regs->int_code & 0x200) /* Trap during transaction */
92 if (uprobe_pre_sstep_notifier(regs))
96 if (uprobe_post_sstep_notifier(regs))
104 void arch_uprobe_abort_xol(struct arch_uprobe *auprobe, struct pt_regs *regs)
106 clear_thread_flag(TIF_UPROBE_SINGLESTEP);
107 regs->int_code = auprobe->saved_int_code;
108 regs->psw.addr = current->utask->vaddr;
111 unsigned long arch_uretprobe_hijack_return_addr(unsigned long trampoline,
112 struct pt_regs *regs)
116 orig = regs->gprs[14];
117 regs->gprs[14] = trampoline;
121 /* Instruction Emulation */
123 static void adjust_psw_addr(psw_t *psw, unsigned long len)
125 psw->addr = __rewind_psw(*psw, -len);
128 #define EMU_ILLEGAL_OP 1
129 #define EMU_SPECIFICATION 2
130 #define EMU_ADDRESSING 3
132 #define emu_load_ril(ptr, output) \
134 unsigned int mask = sizeof(*(ptr)) - 1; \
135 __typeof__(*(ptr)) input; \
138 if (!test_facility(34)) \
139 __rc = EMU_ILLEGAL_OP; \
140 else if ((u64 __force)ptr & mask) \
141 __rc = EMU_SPECIFICATION; \
142 else if (get_user(input, ptr)) \
143 __rc = EMU_ADDRESSING; \
149 #define emu_store_ril(ptr, input) \
151 unsigned int mask = sizeof(*(ptr)) - 1; \
154 if (!test_facility(34)) \
155 __rc = EMU_ILLEGAL_OP; \
156 else if ((u64 __force)ptr & mask) \
157 __rc = EMU_SPECIFICATION; \
158 else if (put_user(*(input), ptr)) \
159 __rc = EMU_ADDRESSING; \
163 #define emu_cmp_ril(regs, ptr, cmp) \
165 unsigned int mask = sizeof(*(ptr)) - 1; \
166 __typeof__(*(ptr)) input; \
169 if (!test_facility(34)) \
170 __rc = EMU_ILLEGAL_OP; \
171 else if ((u64 __force)ptr & mask) \
172 __rc = EMU_SPECIFICATION; \
173 else if (get_user(input, ptr)) \
174 __rc = EMU_ADDRESSING; \
175 else if (input > *(cmp)) \
176 psw_bits((regs)->psw).cc = 1; \
177 else if (input < *(cmp)) \
178 psw_bits((regs)->psw).cc = 2; \
180 psw_bits((regs)->psw).cc = 0; \
191 union split_register {
201 * pc relative instructions are emulated, since parameters may not be
202 * accessible from the xol area due to range limitations.
204 static void handle_insn_ril(struct arch_uprobe *auprobe, struct pt_regs *regs)
206 union split_register *rx;
207 struct insn_ril *insn;
212 insn = (struct insn_ril *) &auprobe->insn;
213 rx = (union split_register *) ®s->gprs[insn->reg];
214 uptr = (void *)(regs->psw.addr + (insn->disp * 2));
215 ilen = insn_length(insn->opc0);
217 switch (insn->opc0) {
219 switch (insn->opc1) {
220 case 0x00: /* larl */
221 rx->u64 = (unsigned long)uptr;
226 switch (insn->opc1) {
227 case 0x02: /* llhrl */
228 rc = emu_load_ril((u16 __user *)uptr, &rx->u32[1]);
230 case 0x04: /* lghrl */
231 rc = emu_load_ril((s16 __user *)uptr, &rx->u64);
233 case 0x05: /* lhrl */
234 rc = emu_load_ril((s16 __user *)uptr, &rx->u32[1]);
236 case 0x06: /* llghrl */
237 rc = emu_load_ril((u16 __user *)uptr, &rx->u64);
239 case 0x08: /* lgrl */
240 rc = emu_load_ril((u64 __user *)uptr, &rx->u64);
242 case 0x0c: /* lgfrl */
243 rc = emu_load_ril((s32 __user *)uptr, &rx->u64);
246 rc = emu_load_ril((u32 __user *)uptr, &rx->u32[1]);
248 case 0x0e: /* llgfrl */
249 rc = emu_load_ril((u32 __user *)uptr, &rx->u64);
251 case 0x07: /* sthrl */
252 rc = emu_store_ril((u16 __user *)uptr, &rx->u16[3]);
254 case 0x0b: /* stgrl */
255 rc = emu_store_ril((u64 __user *)uptr, &rx->u64);
257 case 0x0f: /* strl */
258 rc = emu_store_ril((u32 __user *)uptr, &rx->u32[1]);
263 switch (insn->opc1) {
264 case 0x02: /* pfdrl */
265 if (!test_facility(34))
268 case 0x04: /* cghrl */
269 rc = emu_cmp_ril(regs, (s16 __user *)uptr, &rx->s64);
271 case 0x05: /* chrl */
272 rc = emu_cmp_ril(regs, (s16 __user *)uptr, &rx->s32[1]);
274 case 0x06: /* clghrl */
275 rc = emu_cmp_ril(regs, (u16 __user *)uptr, &rx->u64);
277 case 0x07: /* clhrl */
278 rc = emu_cmp_ril(regs, (u16 __user *)uptr, &rx->u32[1]);
280 case 0x08: /* cgrl */
281 rc = emu_cmp_ril(regs, (s64 __user *)uptr, &rx->s64);
283 case 0x0a: /* clgrl */
284 rc = emu_cmp_ril(regs, (u64 __user *)uptr, &rx->u64);
286 case 0x0c: /* cgfrl */
287 rc = emu_cmp_ril(regs, (s32 __user *)uptr, &rx->s64);
290 rc = emu_cmp_ril(regs, (s32 __user *)uptr, &rx->s32[1]);
292 case 0x0e: /* clgfrl */
293 rc = emu_cmp_ril(regs, (u32 __user *)uptr, &rx->u64);
295 case 0x0f: /* clrl */
296 rc = emu_cmp_ril(regs, (u32 __user *)uptr, &rx->u32[1]);
301 adjust_psw_addr(®s->psw, ilen);
304 regs->int_code = ilen << 16 | 0x0001;
305 do_report_trap(regs, SIGILL, ILL_ILLOPC, NULL);
307 case EMU_SPECIFICATION:
308 regs->int_code = ilen << 16 | 0x0006;
309 do_report_trap(regs, SIGILL, ILL_ILLOPC , NULL);
312 regs->int_code = ilen << 16 | 0x0005;
313 do_report_trap(regs, SIGSEGV, SEGV_MAPERR, NULL);
318 bool arch_uprobe_skip_sstep(struct arch_uprobe *auprobe, struct pt_regs *regs)
320 if ((psw_bits(regs->psw).eaba == PSW_AMODE_24BIT) ||
321 ((psw_bits(regs->psw).eaba == PSW_AMODE_31BIT) &&
322 !is_compat_task())) {
323 regs->psw.addr = __rewind_psw(regs->psw, UPROBE_SWBP_INSN_SIZE);
324 do_report_trap(regs, SIGILL, ILL_ILLADR, NULL);
327 if (probe_is_insn_relative_long(auprobe->insn)) {
328 handle_insn_ril(auprobe, regs);