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Diffstat (limited to 'gdbserver/linux-aarch64-ipa.cc')
| -rw-r--r-- | gdbserver/linux-aarch64-ipa.cc | 209 |
1 files changed, 209 insertions, 0 deletions
diff --git a/gdbserver/linux-aarch64-ipa.cc b/gdbserver/linux-aarch64-ipa.cc new file mode 100644 index 0000000..694dfd7 --- /dev/null +++ b/gdbserver/linux-aarch64-ipa.cc @@ -0,0 +1,209 @@ +/* GNU/Linux/AArch64 specific low level interface, for the in-process + agent library for GDB. + + Copyright (C) 2015-2020 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 and pauth not yet supported. */ + +const struct target_desc * +get_ipa_tdesc (int idx) +{ + return aarch64_linux_read_description (0, 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 and pauth not yet supported. */ + aarch64_linux_read_description (0, false); +} |