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- /* libunwind - a platform-independent unwind library
- Copyright (C) 2002 Hewlett-Packard Co
- Copyright (C) 2007 David Mosberger-Tang
- Contributed by David Mosberger-Tang <dmosberger@gmail.com>
- Modified for x86_64 by Max Asbock <masbock@us.ibm.com>
- This file is part of libunwind.
- Permission is hereby granted, free of charge, to any person obtaining
- a copy of this software and associated documentation files (the
- "Software"), to deal in the Software without restriction, including
- without limitation the rights to use, copy, modify, merge, publish,
- distribute, sublicense, and/or sell copies of the Software, and to
- permit persons to whom the Software is furnished to do so, subject to
- the following conditions:
- The above copyright notice and this permission notice shall be
- included in all copies or substantial portions of the Software.
- THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
- EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
- MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
- NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
- LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
- OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
- WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. */
- #ifdef HAVE_CONFIG_H
- #include <config.h>
- #endif
- #include <stdlib.h>
- #include <string.h>
- #include <sys/mman.h>
- #include "unwind_i.h"
- #ifdef UNW_REMOTE_ONLY
- /* unw_local_addr_space is a NULL pointer in this case. */
- PROTECTED unw_addr_space_t unw_local_addr_space;
- #else /* !UNW_REMOTE_ONLY */
- static struct unw_addr_space local_addr_space;
- PROTECTED unw_addr_space_t unw_local_addr_space = &local_addr_space;
- HIDDEN unw_dyn_info_list_t _U_dyn_info_list;
- /* XXX fix me: there is currently no way to locate the dyn-info list
- by a remote unwinder. On ia64, this is done via a special
- unwind-table entry. Perhaps something similar can be done with
- DWARF2 unwind info. */
- static void
- put_unwind_info (unw_addr_space_t as, unw_proc_info_t *proc_info, void *arg)
- {
- /* it's a no-op */
- }
- static int
- get_dyn_info_list_addr (unw_addr_space_t as, unw_word_t *dyn_info_list_addr,
- void *arg)
- {
- *dyn_info_list_addr = (unw_word_t) &_U_dyn_info_list;
- return 0;
- }
- #define PAGE_SIZE 4096
- #define PAGE_START(a) ((a) & ~(PAGE_SIZE-1))
- static int (*mem_validate_func) (void *addr, size_t len);
- static int msync_validate (void *addr, size_t len)
- {
- return msync (addr, len, MS_ASYNC);
- }
- #ifdef HAVE_MINCORE
- static int mincore_validate (void *addr, size_t len)
- {
- unsigned char mvec[2]; /* Unaligned access may cross page boundary */
- return mincore (addr, len, mvec);
- }
- #endif
- /* Initialise memory validation method. On linux kernels <2.6.21,
- mincore() returns incorrect value for MAP_PRIVATE mappings,
- such as stacks. If mincore() was available at compile time,
- check if we can actually use it. If not, use msync() instead. */
- HIDDEN void
- tdep_init_mem_validate (void)
- {
- #ifdef HAVE_MINCORE
- unsigned char present = 1;
- if (mincore (&present, 1, &present) == 0)
- {
- Debug(1, "using mincore to validate memory\n");
- mem_validate_func = mincore_validate;
- }
- else
- #endif
- {
- Debug(1, "using msync to validate memory\n");
- mem_validate_func = msync_validate;
- }
- }
- /* Cache of already validated addresses */
- #define NLGA 4
- static unw_word_t last_good_addr[NLGA];
- static int lga_victim;
- static int
- validate_mem (unw_word_t addr)
- {
- int i, victim;
- size_t len;
- if (PAGE_START(addr + sizeof (unw_word_t) - 1) == PAGE_START(addr))
- len = PAGE_SIZE;
- else
- len = PAGE_SIZE * 2;
- addr = PAGE_START(addr);
- if (addr == 0)
- return -1;
- for (i = 0; i < NLGA; i++)
- {
- if (last_good_addr[i] && (addr == last_good_addr[i]))
- return 0;
- }
- if (mem_validate_func ((void *) addr, len) == -1)
- return -1;
- victim = lga_victim;
- for (i = 0; i < NLGA; i++) {
- if (!last_good_addr[victim]) {
- last_good_addr[victim] = addr;
- return 0;
- }
- victim = (victim + 1) % NLGA;
- }
- /* All slots full. Evict the victim. */
- last_good_addr[victim] = addr;
- victim = (victim + 1) % NLGA;
- lga_victim = victim;
- return 0;
- }
- static int
- access_mem (unw_addr_space_t as, unw_word_t addr, unw_word_t *val, int write,
- void *arg)
- {
- if (unlikely (write))
- {
- Debug (16, "mem[%016lx] <- %lx\n", addr, *val);
- *(unw_word_t *) addr = *val;
- }
- else
- {
- /* validate address */
- const struct cursor *c = (const struct cursor *)arg;
- if (likely (c != 0) && unlikely (c->validate)
- && unlikely (validate_mem (addr)))
- return -1;
- *val = *(unw_word_t *) addr;
- Debug (16, "mem[%016lx] -> %lx\n", addr, *val);
- }
- return 0;
- }
- static int
- access_reg (unw_addr_space_t as, unw_regnum_t reg, unw_word_t *val, int write,
- void *arg)
- {
- unw_word_t *addr;
- ucontext_t *uc = ((struct cursor *)arg)->uc;
- if (unw_is_fpreg (reg))
- goto badreg;
- if (!(addr = x86_64_r_uc_addr (uc, reg)))
- goto badreg;
- if (write)
- {
- *(unw_word_t *) addr = *val;
- Debug (12, "%s <- 0x%016lx\n", unw_regname (reg), *val);
- }
- else
- {
- *val = *(unw_word_t *) addr;
- Debug (12, "%s -> 0x%016lx\n", unw_regname (reg), *val);
- }
- return 0;
- badreg:
- Debug (1, "bad register number %u\n", reg);
- return -UNW_EBADREG;
- }
- static int
- access_fpreg (unw_addr_space_t as, unw_regnum_t reg, unw_fpreg_t *val,
- int write, void *arg)
- {
- ucontext_t *uc = ((struct cursor *)arg)->uc;
- unw_fpreg_t *addr;
- if (!unw_is_fpreg (reg))
- goto badreg;
- if (!(addr = x86_64_r_uc_addr (uc, reg)))
- goto badreg;
- if (write)
- {
- Debug (12, "%s <- %08lx.%08lx.%08lx\n", unw_regname (reg),
- ((long *)val)[0], ((long *)val)[1], ((long *)val)[2]);
- *(unw_fpreg_t *) addr = *val;
- }
- else
- {
- *val = *(unw_fpreg_t *) addr;
- Debug (12, "%s -> %08lx.%08lx.%08lx\n", unw_regname (reg),
- ((long *)val)[0], ((long *)val)[1], ((long *)val)[2]);
- }
- return 0;
- badreg:
- Debug (1, "bad register number %u\n", reg);
- /* attempt to access a non-preserved register */
- return -UNW_EBADREG;
- }
- static int
- get_static_proc_name (unw_addr_space_t as, unw_word_t ip,
- char *buf, size_t buf_len, unw_word_t *offp,
- void *arg)
- {
- #if HAVE_SGX
- return -1;
- #else
- return _Uelf64_get_proc_name (as, getpid (), ip, buf, buf_len, offp);
- #endif
- }
- HIDDEN void
- x86_64_local_addr_space_init (void)
- {
- memset (&local_addr_space, 0, sizeof (local_addr_space));
- local_addr_space.caching_policy = UNW_CACHE_GLOBAL;
- local_addr_space.acc.find_proc_info = dwarf_find_proc_info;
- local_addr_space.acc.put_unwind_info = put_unwind_info;
- local_addr_space.acc.get_dyn_info_list_addr = get_dyn_info_list_addr;
- local_addr_space.acc.access_mem = access_mem;
- local_addr_space.acc.access_reg = access_reg;
- local_addr_space.acc.access_fpreg = access_fpreg;
- local_addr_space.acc.resume = x86_64_local_resume;
- local_addr_space.acc.get_proc_name = get_static_proc_name;
- unw_flush_cache (&local_addr_space, 0, 0);
- memset (last_good_addr, 0, sizeof (unw_word_t) * NLGA);
- lga_victim = 0;
- }
- #endif /* !UNW_REMOTE_ONLY */
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