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eh_elf: fix a few more errors

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This commit is contained in:
Théophile Bastian 2018-06-15 00:01:53 +02:00
parent 7494efbb16
commit bfd5b164fa
2 changed files with 49 additions and 19 deletions
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60
src/eh_elf/eh_elf.c
View file

@ -37,18 +37,24 @@ void eh_elf_clear() {
}
static struct {
unw_addr_space_t addr_space;
unw_accessors_t *accessors;
void* arg;
struct cursor* cursor;
int last_rc;
} _fetch_state;
static uintptr_t fetchw_here(uintptr_t addr) {
uintptr_t out;
fetchw(_fetch_state.addr_space,
_fetch_state.accessors,
&addr,
&out,
_fetch_state.arg);
int rv = _fetch_state.cursor->dwarf.as->acc.access_mem(
_fetch_state.cursor->dwarf.as,
addr,
&out,
0,
_fetch_state.cursor->dwarf.as_arg);
if(rv != 0) {
Debug(1, "dwarf_get error %d\n", rv);
_fetch_state.last_rc = rv;
}
return out;
}
@ -64,6 +70,7 @@ int eh_elf_step_cursor(struct cursor *cursor) {
// Check for the end of the call chain
if(DWARF_IS_NULL_LOC(cursor->dwarf.loc[UNW_TDEP_IP]))
return 0;
if(!DWARF_IS_NULL_LOC(cursor->dwarf.loc[UNW_TDEP_BP])) {
uintptr_t bp;
dwarf_get(&cursor->dwarf,
@ -74,8 +81,10 @@ int eh_elf_step_cursor(struct cursor *cursor) {
// Retrieve memory map entry
mmap_entry_t* mmap_entry = mmap_get_entry(ip);
if(mmap_entry == NULL)
if(mmap_entry == NULL) {
Debug(3, "No such mmap entry :(\n");
return -1;
}
Debug(5, "In memory map entry %lx-%lx (%s) - off %lx, ip %lx%s\n",
mmap_entry->beg_ip,
@ -94,19 +103,18 @@ int eh_elf_step_cursor(struct cursor *cursor) {
// Setup an eh_elf context
unwind_context_t eh_elf_context;
eh_elf_context.rip = ip;
dwarf_get(&cursor->dwarf,
cursor->dwarf.loc[UNW_TDEP_SP], &eh_elf_context.rsp);
eh_elf_context.rsp = cursor->dwarf.cfa;
dwarf_get(&cursor->dwarf,
cursor->dwarf.loc[UNW_TDEP_BP], &eh_elf_context.rbp);
// Set _fetch_state before passing fetchw_here
_fetch_state.addr_space = cursor->dwarf.as;
_fetch_state.accessors = &cursor->dwarf.as->acc;
_fetch_state.arg = &cursor->dwarf.as_arg;
_fetch_state.cursor = cursor;
_fetch_state.last_rc = 0;
Debug(4, "Unwinding in mmap entry %s at position 0x%lx\n",
Debug(4, "Unwinding in mmap entry %s at position 0x%lx (sp=%016lx)\n",
mmap_entry->object_name,
ip - mmap_entry->offset);
ip - mmap_entry->offset,
eh_elf_context.rsp);
// Call fde_func
eh_elf_context = fde_func(
@ -114,6 +122,11 @@ int eh_elf_step_cursor(struct cursor *cursor) {
ip - mmap_entry->offset,
fetchw_here);
if(_fetch_state.last_rc != 0) {
// access_mem error
return -4;
}
if(eh_elf_context.rbp + 1 == 0
&& eh_elf_context.rsp + 1 == 0
&& eh_elf_context.rip + 1 == 0) {
@ -122,6 +135,17 @@ int eh_elf_step_cursor(struct cursor *cursor) {
return -3;
}
if(eh_elf_context.rip < 10 || eh_elf_context.rsp < 10)
return -5;
Debug(3, "EH_ELF: bp=%016lx sp=%016lx ip=%016lx\n",
eh_elf_context.rbp,
eh_elf_context.rsp,
eh_elf_context.rip);
Debug(3, "MMAP: %s %lx\n",
mmap_entry->object_name,
ip - mmap_entry->offset);
// Push back the data into libunwind's structures
for (int i = 0; i < DWARF_NUM_PRESERVED_REGS; ++i)
cursor->dwarf.loc[i] = DWARF_NULL_LOC;
@ -129,13 +153,13 @@ int eh_elf_step_cursor(struct cursor *cursor) {
cursor->dwarf.loc[UNW_TDEP_BP] = of_eh_elf_loc(eh_elf_context.rbp);
cursor->dwarf.loc[UNW_TDEP_SP] = of_eh_elf_loc(eh_elf_context.rsp);
cursor->dwarf.loc[UNW_TDEP_IP] = of_eh_elf_loc(eh_elf_context.rip);
cursor->dwarf.use_prev_instr = 1;
cursor->dwarf.use_prev_instr = 0;
cursor->frame_info.frame_type = UNW_X86_64_FRAME_GUESSED;
cursor->frame_info.cfa_reg_rsp = 0;
cursor->frame_info.cfa_reg_offset = 16;
cursor->frame_info.rbp_cfa_offset = -16;
cursor->dwarf.cfa += 16;
cursor->dwarf.cfa = eh_elf_context.rsp;
cursor->dwarf.ip = eh_elf_context.rip;
return 1;

8
src/x86_64/Gstep.c
View file

@ -28,6 +28,7 @@ WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. */
#include "unwind_i.h"
#include "../eh_elf/eh_elf.h"
#include <signal.h>
#include "remote.h"
/* Recognise PLT entries such as:
3bdf0: ff 25 e2 49 13 00 jmpq *0x1349e2(%rip)
@ -67,6 +68,8 @@ unw_step (unw_cursor_t *cursor)
Debug (1, "(cursor=%p, ip=0x%016lx, cfa=0x%016lx)\n",
c, c->dwarf.ip, c->dwarf.cfa);
c->sigcontext_format = X86_64_SCF_NONE;
// Try eh_elf based unwinding...
ret = eh_elf_step_cursor(c);
@ -79,7 +82,6 @@ unw_step (unw_cursor_t *cursor)
}
/* Try DWARF-based unwinding... */
c->sigcontext_format = X86_64_SCF_NONE;
ret = dwarf_step (&c->dwarf);
#if CONSERVATIVE_CHECKS
@ -102,6 +104,10 @@ unw_step (unw_cursor_t *cursor)
c->dwarf.ip = 0;
ret = 0;
}
uintptr_t dbp;
dwarf_get(&c->dwarf, c->dwarf.loc[RBP], &dbp);
Debug (3, " DWARF: bp=%016lx sp=%016lx ip=%016lx\n", dbp, c->dwarf.cfa, c->dwarf.ip);
}
else
{