^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2) * Dynamic function tracing support.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4) * Copyright (C) 2008 Shaohua Li <shaohua.li@intel.com>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6) * For licencing details, see COPYING.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 7) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 8) * Defines low-level handling of mcount calls when the kernel
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 9) * is compiled with the -pg flag. When using dynamic ftrace, the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 10) * mcount call-sites get patched lazily with NOP till they are
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 11) * enabled. All code mutation routines here take effect atomically.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 12) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 13)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 14) #include <linux/uaccess.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 15) #include <linux/ftrace.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 16)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 17) #include <asm/cacheflush.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 18) #include <asm/patch.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 19)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 20) /* In IA64, each function will be added below two bundles with -pg option */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 21) static unsigned char __attribute__((aligned(8)))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 22) ftrace_orig_code[MCOUNT_INSN_SIZE] = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 23) 0x02, 0x40, 0x31, 0x10, 0x80, 0x05, /* alloc r40=ar.pfs,12,8,0 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 24) 0xb0, 0x02, 0x00, 0x00, 0x42, 0x40, /* mov r43=r0;; */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 25) 0x05, 0x00, 0xc4, 0x00, /* mov r42=b0 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 26) 0x11, 0x48, 0x01, 0x02, 0x00, 0x21, /* mov r41=r1 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 27) 0x00, 0x00, 0x00, 0x02, 0x00, 0x00, /* nop.i 0x0 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 28) 0x08, 0x00, 0x00, 0x50 /* br.call.sptk.many b0 = _mcount;; */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 29) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 30)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 31) struct ftrace_orig_insn {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 32) u64 dummy1, dummy2, dummy3;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 33) u64 dummy4:64-41+13;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 34) u64 imm20:20;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 35) u64 dummy5:3;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 36) u64 sign:1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 37) u64 dummy6:4;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 38) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 39)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 40) /* mcount stub will be converted below for nop */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 41) static unsigned char ftrace_nop_code[MCOUNT_INSN_SIZE] = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 42) 0x00, 0x00, 0x00, 0x00, 0x01, 0x00, /* [MII] nop.m 0x0 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 43) 0x30, 0x00, 0x00, 0x60, 0x00, 0x00, /* mov r3=ip */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 44) 0x00, 0x00, 0x04, 0x00, /* nop.i 0x0 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 45) 0x05, 0x00, 0x00, 0x00, 0x01, 0x00, /* [MLX] nop.m 0x0 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 46) 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, /* nop.x 0x0;; */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 47) 0x00, 0x00, 0x04, 0x00
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 48) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 49)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 50) static unsigned char *ftrace_nop_replace(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 51) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 52) return ftrace_nop_code;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 53) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 54)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 55) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 56) * mcount stub will be converted below for call
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 57) * Note: Just the last instruction is changed against nop
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 58) * */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 59) static unsigned char __attribute__((aligned(8)))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 60) ftrace_call_code[MCOUNT_INSN_SIZE] = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 61) 0x00, 0x00, 0x00, 0x00, 0x01, 0x00, /* [MII] nop.m 0x0 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 62) 0x30, 0x00, 0x00, 0x60, 0x00, 0x00, /* mov r3=ip */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 63) 0x00, 0x00, 0x04, 0x00, /* nop.i 0x0 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 64) 0x05, 0x00, 0x00, 0x00, 0x01, 0x00, /* [MLX] nop.m 0x0 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 65) 0xff, 0xff, 0xff, 0xff, 0x7f, 0x00, /* brl.many .;;*/
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 66) 0xf8, 0xff, 0xff, 0xc8
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 67) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 68)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 69) struct ftrace_call_insn {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 70) u64 dummy1, dummy2;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 71) u64 dummy3:48;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 72) u64 imm39_l:16;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 73) u64 imm39_h:23;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 74) u64 dummy4:13;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 75) u64 imm20:20;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 76) u64 dummy5:3;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 77) u64 i:1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 78) u64 dummy6:4;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 79) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 80)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 81) static unsigned char *ftrace_call_replace(unsigned long ip, unsigned long addr)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 82) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 83) struct ftrace_call_insn *code = (void *)ftrace_call_code;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 84) unsigned long offset = addr - (ip + 0x10);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 85)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 86) code->imm39_l = offset >> 24;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 87) code->imm39_h = offset >> 40;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 88) code->imm20 = offset >> 4;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 89) code->i = offset >> 63;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 90) return ftrace_call_code;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 91) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 92)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 93) static int
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 94) ftrace_modify_code(unsigned long ip, unsigned char *old_code,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 95) unsigned char *new_code, int do_check)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 96) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 97) unsigned char replaced[MCOUNT_INSN_SIZE];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 98)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 99) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 100) * Note:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 101) * We are paranoid about modifying text, as if a bug was to happen, it
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 102) * could cause us to read or write to someplace that could cause harm.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 103) * Carefully read and modify the code with probe_kernel_*(), and make
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 104) * sure what we read is what we expected it to be before modifying it.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 105) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 106)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 107) if (!do_check)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 108) goto skip_check;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 109)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 110) /* read the text we want to modify */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 111) if (copy_from_kernel_nofault(replaced, (void *)ip, MCOUNT_INSN_SIZE))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 112) return -EFAULT;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 113)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 114) /* Make sure it is what we expect it to be */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 115) if (memcmp(replaced, old_code, MCOUNT_INSN_SIZE) != 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 116) return -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 117)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 118) skip_check:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 119) /* replace the text with the new text */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 120) if (copy_to_kernel_nofault(((void *)ip), new_code, MCOUNT_INSN_SIZE))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 121) return -EPERM;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 122) flush_icache_range(ip, ip + MCOUNT_INSN_SIZE);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 123)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 124) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 125) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 126)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 127) static int ftrace_make_nop_check(struct dyn_ftrace *rec, unsigned long addr)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 128) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 129) unsigned char __attribute__((aligned(8))) replaced[MCOUNT_INSN_SIZE];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 130) unsigned long ip = rec->ip;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 131)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 132) if (copy_from_kernel_nofault(replaced, (void *)ip, MCOUNT_INSN_SIZE))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 133) return -EFAULT;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 134) if (rec->flags & FTRACE_FL_CONVERTED) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 135) struct ftrace_call_insn *call_insn, *tmp_call;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 136)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 137) call_insn = (void *)ftrace_call_code;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 138) tmp_call = (void *)replaced;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 139) call_insn->imm39_l = tmp_call->imm39_l;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 140) call_insn->imm39_h = tmp_call->imm39_h;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 141) call_insn->imm20 = tmp_call->imm20;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 142) call_insn->i = tmp_call->i;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 143) if (memcmp(replaced, ftrace_call_code, MCOUNT_INSN_SIZE) != 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 144) return -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 145) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 146) } else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 147) struct ftrace_orig_insn *call_insn, *tmp_call;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 148)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 149) call_insn = (void *)ftrace_orig_code;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 150) tmp_call = (void *)replaced;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 151) call_insn->sign = tmp_call->sign;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 152) call_insn->imm20 = tmp_call->imm20;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 153) if (memcmp(replaced, ftrace_orig_code, MCOUNT_INSN_SIZE) != 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 154) return -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 155) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 156) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 157) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 158)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 159) int ftrace_make_nop(struct module *mod,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 160) struct dyn_ftrace *rec, unsigned long addr)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 161) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 162) int ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 163) char *new;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 164)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 165) ret = ftrace_make_nop_check(rec, addr);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 166) if (ret)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 167) return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 168) new = ftrace_nop_replace();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 169) return ftrace_modify_code(rec->ip, NULL, new, 0);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 170) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 171)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 172) int ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 173) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 174) unsigned long ip = rec->ip;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 175) unsigned char *old, *new;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 176)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 177) old= ftrace_nop_replace();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 178) new = ftrace_call_replace(ip, addr);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 179) return ftrace_modify_code(ip, old, new, 1);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 180) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 181)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 182) /* in IA64, _mcount can't directly call ftrace_stub. Only jump is ok */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 183) int ftrace_update_ftrace_func(ftrace_func_t func)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 184) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 185) unsigned long ip;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 186) unsigned long addr = ((struct fnptr *)ftrace_call)->ip;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 187)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 188) if (func == ftrace_stub)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 189) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 190) ip = ((struct fnptr *)func)->ip;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 191)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 192) ia64_patch_imm64(addr + 2, ip);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 193)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 194) flush_icache_range(addr, addr + 16);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 195) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 196) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 197)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 198) /* run from kstop_machine */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 199) int __init ftrace_dyn_arch_init(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 200) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 201) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 202) }
Orange Pi5 kernel
Deprecated Linux kernel 5.10.110 for OrangePi 5/5B/5+ boards
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