| /* GNU/Linux/AArch64 specific low level interface, for the in-process |
| agent library for GDB. |
| |
| Copyright (C) 2015-2021 Free Software Foundation, Inc. |
| |
| This file is part of GDB. |
| |
| 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 3 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/>. */ |
| |
| #include "server.h" |
| #include <sys/mman.h> |
| #include "tracepoint.h" |
| #include <elf.h> |
| #ifdef HAVE_GETAUXVAL |
| #include <sys/auxv.h> |
| #endif |
| #include "linux-aarch64-tdesc.h" |
| |
| /* Each register saved by the jump pad is in a 16 byte cell. */ |
| #define FT_CR_SIZE 16 |
| |
| #define FT_CR_FPCR 0 |
| #define FT_CR_FPSR 1 |
| #define FT_CR_CPSR 2 |
| #define FT_CR_PC 3 |
| #define FT_CR_SP 4 |
| #define FT_CR_X0 5 |
| #define FT_CR_GPR(n) (FT_CR_X0 + (n)) |
| #define FT_CR_FPR(n) (FT_CR_GPR (31) + (n)) |
| |
| /* Mapping between registers collected by the jump pad and GDB's register |
| array layout used by regcache. |
| |
| See linux-aarch64-low.c (aarch64_install_fast_tracepoint_jump_pad) for |
| more details. */ |
| |
| static const int aarch64_ft_collect_regmap[] = { |
| FT_CR_GPR (0), |
| FT_CR_GPR (1), |
| FT_CR_GPR (2), |
| FT_CR_GPR (3), |
| FT_CR_GPR (4), |
| FT_CR_GPR (5), |
| FT_CR_GPR (6), |
| FT_CR_GPR (7), |
| FT_CR_GPR (8), |
| FT_CR_GPR (9), |
| FT_CR_GPR (10), |
| FT_CR_GPR (11), |
| FT_CR_GPR (12), |
| FT_CR_GPR (13), |
| FT_CR_GPR (14), |
| FT_CR_GPR (15), |
| FT_CR_GPR (16), |
| FT_CR_GPR (17), |
| FT_CR_GPR (18), |
| FT_CR_GPR (19), |
| FT_CR_GPR (20), |
| FT_CR_GPR (21), |
| FT_CR_GPR (22), |
| FT_CR_GPR (23), |
| FT_CR_GPR (24), |
| FT_CR_GPR (25), |
| FT_CR_GPR (26), |
| FT_CR_GPR (27), |
| FT_CR_GPR (28), |
| /* FP */ |
| FT_CR_GPR (29), |
| /* LR */ |
| FT_CR_GPR (30), |
| FT_CR_SP, |
| FT_CR_PC, |
| FT_CR_CPSR, |
| FT_CR_FPR (0), |
| FT_CR_FPR (1), |
| FT_CR_FPR (2), |
| FT_CR_FPR (3), |
| FT_CR_FPR (4), |
| FT_CR_FPR (5), |
| FT_CR_FPR (6), |
| FT_CR_FPR (7), |
| FT_CR_FPR (8), |
| FT_CR_FPR (9), |
| FT_CR_FPR (10), |
| FT_CR_FPR (11), |
| FT_CR_FPR (12), |
| FT_CR_FPR (13), |
| FT_CR_FPR (14), |
| FT_CR_FPR (15), |
| FT_CR_FPR (16), |
| FT_CR_FPR (17), |
| FT_CR_FPR (18), |
| FT_CR_FPR (19), |
| FT_CR_FPR (20), |
| FT_CR_FPR (21), |
| FT_CR_FPR (22), |
| FT_CR_FPR (23), |
| FT_CR_FPR (24), |
| FT_CR_FPR (25), |
| FT_CR_FPR (26), |
| FT_CR_FPR (27), |
| FT_CR_FPR (28), |
| FT_CR_FPR (29), |
| FT_CR_FPR (30), |
| FT_CR_FPR (31), |
| FT_CR_FPSR, |
| FT_CR_FPCR |
| }; |
| |
| #define AARCH64_NUM_FT_COLLECT_GREGS \ |
| (sizeof (aarch64_ft_collect_regmap) / sizeof(aarch64_ft_collect_regmap[0])) |
| |
| /* Fill in REGCACHE with registers saved by the jump pad in BUF. */ |
| |
| void |
| supply_fast_tracepoint_registers (struct regcache *regcache, |
| const unsigned char *buf) |
| { |
| int i; |
| |
| for (i = 0; i < AARCH64_NUM_FT_COLLECT_GREGS; i++) |
| supply_register (regcache, i, |
| ((char *) buf) |
| + (aarch64_ft_collect_regmap[i] * FT_CR_SIZE)); |
| } |
| |
| ULONGEST |
| get_raw_reg (const unsigned char *raw_regs, int regnum) |
| { |
| if (regnum >= AARCH64_NUM_FT_COLLECT_GREGS) |
| return 0; |
| |
| return *(ULONGEST *) (raw_regs |
| + aarch64_ft_collect_regmap[regnum] * FT_CR_SIZE); |
| } |
| |
| /* Return target_desc to use for IPA, given the tdesc index passed by |
| gdbserver. Index is ignored, since we have only one tdesc |
| at the moment. SVE, pauth and MTE not yet supported. */ |
| |
| const struct target_desc * |
| get_ipa_tdesc (int idx) |
| { |
| return aarch64_linux_read_description (0, false, false); |
| } |
| |
| /* Allocate buffer for the jump pads. The branch instruction has a reach |
| of +/- 128MiB, and the executable is loaded at 0x400000 (4MiB). |
| To maximize the area of executable that can use tracepoints, try |
| allocating at 0x400000 - size initially, decreasing until we hit |
| a free area. */ |
| |
| void * |
| alloc_jump_pad_buffer (size_t size) |
| { |
| uintptr_t addr; |
| uintptr_t exec_base = getauxval (AT_PHDR); |
| int pagesize; |
| void *res; |
| |
| if (exec_base == 0) |
| exec_base = 0x400000; |
| |
| pagesize = sysconf (_SC_PAGE_SIZE); |
| if (pagesize == -1) |
| perror_with_name ("sysconf"); |
| |
| addr = exec_base - size; |
| |
| /* size should already be page-aligned, but this can't hurt. */ |
| addr &= ~(pagesize - 1); |
| |
| /* Search for a free area. If we hit 0, we're out of luck. */ |
| for (; addr; addr -= pagesize) |
| { |
| /* No MAP_FIXED - we don't want to zap someone's mapping. */ |
| res = mmap ((void *) addr, size, |
| PROT_READ | PROT_WRITE | PROT_EXEC, |
| MAP_PRIVATE | MAP_ANONYMOUS, -1, 0); |
| |
| /* If we got what we wanted, return. */ |
| if ((uintptr_t) res == addr) |
| return res; |
| |
| /* If we got a mapping, but at a wrong address, undo it. */ |
| if (res != MAP_FAILED) |
| munmap (res, size); |
| } |
| |
| return NULL; |
| } |
| |
| void |
| initialize_low_tracepoint (void) |
| { |
| /* SVE, pauth and MTE not yet supported. */ |
| aarch64_linux_read_description (0, false, false); |
| } |