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Change libunwind-ptrace to also look for .debug_frame if nothing found in .eh_frame.

Browse source 
This changes the behavior of libunwind-ptrace to what we do for local
unwinding.

Signed-off-by: Ken Werner <ken.werner@linaro.org>
This commit is contained in:
Ken Werner 2011-07-20 07:18:50 +00:00
parent 545023c207
commit b317cb4829
3 changed files with 173 additions and 145 deletions
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5
src/ptrace/_UPT_create.c
View file

@ -37,5 +37,10 @@ _UPT_create (pid_t pid)
memset (ui, 0, sizeof (*ui));
ui->pid = pid;
ui->di_cache.format = -1;
ui->di_debug.format = -1;
#if UNW_TARGET_IA64
ui->ktab.format = -1;;
#endif
return ui;
}

300
src/ptrace/_UPT_find_proc_info.c
View file

@ -164,7 +164,7 @@ dwarf_read_encoded_pointer (unw_addr_space_t as, unw_accessors_t *a,
pi, valp, arg);
}
HIDDEN unw_dyn_info_t *
HIDDEN int
_UPTi_find_unwind_table (struct UPT_info *ui, unw_addr_space_t as,
char *path, unw_word_t segbase, unw_word_t mapoff,
unw_word_t ip)
@ -176,12 +176,12 @@ _UPTi_find_unwind_table (struct UPT_info *ui, unw_addr_space_t as,
unw_proc_info_t pi;
unw_accessors_t *a;
Elf_W(Ehdr) *ehdr;
int i, ret;
int i, ret, found = 0;
/* XXX: Much of this code is Linux/LSB-specific. */
if (!elf_w(valid_object) (&ui->ei))
return NULL;
return -UNW_ENOINFO;
ehdr = ui->ei.image;
phdr = (Elf_W(Phdr) *) ((char *) ui->ei.image + ehdr->e_phoff);
@ -209,10 +209,116 @@ _UPTi_find_unwind_table (struct UPT_info *ui, unw_addr_space_t as,
break;
}
}
if (!ptxt || !peh_hdr)
#ifdef CONFIG_DEBUG_FRAME
if (!ptxt)
return 0;
if (peh_hdr)
{
/* No .eh_frame found, try .debug_frame. */
if (pdyn)
{
/* For dynamicly linked executables and shared libraries,
DT_PLTGOT is the value that data-relative addresses are
relative to for that object. We call this the "gp". */
Elf_W(Dyn) *dyn = (Elf_W(Dyn) *)(pdyn->p_offset
+ (char *) ui->ei.image);
for (; dyn->d_tag != DT_NULL; ++dyn)
if (dyn->d_tag == DT_PLTGOT)
{
/* Assume that _DYNAMIC is writable and GLIBC has
relocated it (true for x86 at least). */
ui->di_cache.gp = dyn->d_un.d_ptr;
break;
}
}
else
/* Otherwise this is a static executable with no _DYNAMIC. Assume
that data-relative addresses are relative to 0, i.e.,
absolute. */
ui->di_cache.gp = 0;
hdr = (struct dwarf_eh_frame_hdr *) (peh_hdr->p_offset
+ (char *) ui->ei.image);
if (hdr->version != DW_EH_VERSION)
{
Debug (1, "table `%s' has unexpected version %d\n",
path, hdr->version);
return -UNW_ENOINFO;
}
a = unw_get_accessors (unw_local_addr_space);
addr = (unw_word_t) (hdr + 1);
/* Fill in a dummy proc_info structure. We just need to fill in
enough to ensure that dwarf_read_encoded_pointer() can do it's
job. Since we don't have a procedure-context at this point, all
we have to do is fill in the global-pointer. */
memset (&pi, 0, sizeof (pi));
pi.gp = ui->di_cache.gp;
/* (Optionally) read eh_frame_ptr: */
if ((ret = dwarf_read_encoded_pointer (unw_local_addr_space, a,
&addr, hdr->eh_frame_ptr_enc, &pi,
&eh_frame_start, NULL)) < 0)
return -UNW_ENOINFO;
/* (Optionally) read fde_count: */
if ((ret = dwarf_read_encoded_pointer (unw_local_addr_space, a,
&addr, hdr->fde_count_enc, &pi,
&fde_count, NULL)) < 0)
return -UNW_ENOINFO;
if (hdr->table_enc != (DW_EH_PE_datarel | DW_EH_PE_sdata4))
{
#if 1
abort ();
#else
unw_word_t eh_frame_end;
/* If there is no search table or it has an unsupported
encoding, fall back on linear search. */
if (hdr->table_enc == DW_EH_PE_omit)
Debug (4, "EH lacks search table; doing linear search\n");
else
Debug (4, "EH table has encoding 0x%x; doing linear search\n",
hdr->table_enc);
eh_frame_end = max_load_addr; /* XXX can we do better? */
if (hdr->fde_count_enc == DW_EH_PE_omit)
fde_count = ~0UL;
if (hdr->eh_frame_ptr_enc == DW_EH_PE_omit)
abort ();
return linear_search (unw_local_addr_space, ip,
eh_frame_start, eh_frame_end, fde_count,
pi, need_unwind_info, NULL);
#endif
}
load_base = segbase - ptxt->p_vaddr;
ui->di_cache.start_ip = segbase;
ui->di_cache.end_ip = ui->di_cache.start_ip + ptxt->p_memsz;
ui->di_cache.format = UNW_INFO_FORMAT_REMOTE_TABLE;
ui->di_cache.u.rti.name_ptr = 0;
/* two 32-bit values (ip_offset/fde_offset) per table-entry: */
ui->di_cache.u.rti.table_len = (fde_count * 8) / sizeof (unw_word_t);
ui->di_cache.u.rti.table_data = ((load_base + peh_hdr->p_vaddr)
+ (addr - (unw_word_t) ui->ei.image
- peh_hdr->p_offset));
/* For the binary-search table in the eh_frame_hdr, data-relative
means relative to the start of that section... */
ui->di_cache.u.rti.segbase = ((load_base + peh_hdr->p_vaddr)
+ ((unw_word_t) hdr - (unw_word_t) ui->ei.image
- peh_hdr->p_offset));
found = 1;
}
#ifdef CONFIG_DEBUG_FRAME
{
/* Try .debug_frame. */
struct dl_phdr_info info;
info.dlpi_name = path;
@ -231,136 +337,34 @@ _UPTi_find_unwind_table (struct UPT_info *ui, unw_addr_space_t as,
}
info.dlpi_addr = segbase;
if (dwarf_find_debug_frame (0, &ui->di_cache, &info, ip))
return &ui->di_cache;
else
return NULL;
}
#else
return NULL;
found = dwarf_find_debug_frame (found, &ui->di_debug, &info, ip);
}
#endif
if (pdyn)
{
/* For dynamicly linked executables and shared libraries,
DT_PLTGOT is the value that data-relative addresses are
relative to for that object. We call this the "gp". */
Elf_W(Dyn) *dyn = (Elf_W(Dyn) *)(pdyn->p_offset
+ (char *) ui->ei.image);
for (; dyn->d_tag != DT_NULL; ++dyn)
if (dyn->d_tag == DT_PLTGOT)
{
/* Assume that _DYNAMIC is writable and GLIBC has
relocated it (true for x86 at least). */
ui->di_cache.gp = dyn->d_un.d_ptr;
break;
}
}
else
/* Otherwise this is a static executable with no _DYNAMIC. Assume
that data-relative addresses are relative to 0, i.e.,
absolute. */
ui->di_cache.gp = 0;
hdr = (struct dwarf_eh_frame_hdr *) (peh_hdr->p_offset
+ (char *) ui->ei.image);
if (hdr->version != DW_EH_VERSION)
{
Debug (1, "table `%s' has unexpected version %d\n",
path, hdr->version);
return 0;
}
a = unw_get_accessors (unw_local_addr_space);
addr = (unw_word_t) (hdr + 1);
/* Fill in a dummy proc_info structure. We just need to fill in
enough to ensure that dwarf_read_encoded_pointer() can do it's
job. Since we don't have a procedure-context at this point, all
we have to do is fill in the global-pointer. */
memset (&pi, 0, sizeof (pi));
pi.gp = ui->di_cache.gp;
/* (Optionally) read eh_frame_ptr: */
if ((ret = dwarf_read_encoded_pointer (unw_local_addr_space, a,
&addr, hdr->eh_frame_ptr_enc, &pi,
&eh_frame_start, NULL)) < 0)
return NULL;
/* (Optionally) read fde_count: */
if ((ret = dwarf_read_encoded_pointer (unw_local_addr_space, a,
&addr, hdr->fde_count_enc, &pi,
&fde_count, NULL)) < 0)
return NULL;
if (hdr->table_enc != (DW_EH_PE_datarel | DW_EH_PE_sdata4))
{
#if 1
abort ();
#else
unw_word_t eh_frame_end;
/* If there is no search table or it has an unsupported
encoding, fall back on linear search. */
if (hdr->table_enc == DW_EH_PE_omit)
Debug (4, "EH lacks search table; doing linear search\n");
else
Debug (4, "EH table has encoding 0x%x; doing linear search\n",
hdr->table_enc);
eh_frame_end = max_load_addr; /* XXX can we do better? */
if (hdr->fde_count_enc == DW_EH_PE_omit)
fde_count = ~0UL;
if (hdr->eh_frame_ptr_enc == DW_EH_PE_omit)
abort ();
return linear_search (unw_local_addr_space, ip,
eh_frame_start, eh_frame_end, fde_count,
pi, need_unwind_info, NULL);
#endif
}
load_base = segbase - ptxt->p_vaddr;
ui->di_cache.start_ip = segbase;
ui->di_cache.end_ip = ui->di_cache.start_ip + ptxt->p_memsz;
ui->di_cache.format = UNW_INFO_FORMAT_REMOTE_TABLE;
ui->di_cache.u.rti.name_ptr = 0;
/* two 32-bit values (ip_offset/fde_offset) per table-entry: */
ui->di_cache.u.rti.table_len = (fde_count * 8) / sizeof (unw_word_t);
ui->di_cache.u.rti.table_data = ((load_base + peh_hdr->p_vaddr)
+ (addr - (unw_word_t) ui->ei.image
- peh_hdr->p_offset));
/* For the binary-search table in the eh_frame_hdr, data-relative
means relative to the start of that section... */
ui->di_cache.u.rti.segbase = ((load_base + peh_hdr->p_vaddr)
+ ((unw_word_t) hdr - (unw_word_t) ui->ei.image
- peh_hdr->p_offset));
return &ui->di_cache;
return found;
}
#endif /* UNW_TARGET_X86 || UNW_TARGET_X86_64 || UNW_TARGET_HPPA*/
static unw_dyn_info_t *
static int
get_unwind_info (struct UPT_info *ui, unw_addr_space_t as, unw_word_t ip)
{
unsigned long segbase, mapoff;
char path[PATH_MAX];
unw_dyn_info_t *di;
#if UNW_TARGET_IA64 && defined(__linux)
if (!ui->ktab.start_ip && _Uia64_get_kernel_table (&ui->ktab) < 0)
return NULL;
return -UNW_ENOINFO;
if (ip >= ui->ktab.start_ip && ip < ui->ktab.end_ip)
return &ui->ktab;
if (ui->ktab.format != -1 && ip >= ui->ktab.start_ip && ip < ui->ktab.end_ip)
return 0;
#endif
if (ip >= ui->di_cache.start_ip && ip < ui->di_cache.end_ip)
return &ui->di_cache;
if ((ui->di_cache.format != -1
&& ip >= ui->di_cache.start_ip && ip < ui->di_cache.end_ip)
|| (ui->di_debug.format != -1
&& ip >= ui->di_debug.start_ip && ip < ui->di_debug.end_ip))
return 0;
if (ui->ei.image)
{
@ -370,24 +374,36 @@ get_unwind_info (struct UPT_info *ui, unw_addr_space_t as, unw_word_t ip)
/* invalidate the cache: */
ui->di_cache.start_ip = ui->di_cache.end_ip = 0;
ui->di_debug.start_ip = ui->di_debug.end_ip = 0;
ui->di_cache.format = -1;
ui->di_debug.format = -1;
}
if (tdep_get_elf_image (&ui->ei, ui->pid, ip, &segbase, &mapoff, path,
sizeof(path)) < 0)
return NULL;
return -UNW_ENOINFO;
/* Here, SEGBASE is the starting-address of the (mmap'ped) segment
which covers the IP we're looking for. */
di = _UPTi_find_unwind_table (ui, as, path, segbase, mapoff, ip);
if (!di
/* This can happen in corner cases where dynamically generated
code falls into the same page that contains the data-segment
and the page-offset of the code is within the first page of
the executable. */
|| ip < di->start_ip || ip >= di->end_ip)
return NULL;
if (_UPTi_find_unwind_table (ui, as, path, segbase, mapoff, ip) < 0)
return -UNW_ENOINFO;
return di;
/* This can happen in corner cases where dynamically generated
code falls into the same page that contains the data-segment
and the page-offset of the code is within the first page of
the executable. */
if (ui->di_cache.format != -1
&& (ip < ui->di_cache.start_ip || ip >= ui->di_cache.end_ip))
ui->di_cache.format = -1;
if (ui->di_debug.format != -1
&& (ip < ui->di_debug.start_ip || ip >= ui->di_debug.end_ip))
ui->di_debug.format = -1;
if (ui->di_cache.format == -1 && ui->di_debug.format == -1)
return -UNW_ENOINFO;
return 0;
}
int
@ -395,14 +411,13 @@ _UPT_find_proc_info (unw_addr_space_t as, unw_word_t ip, unw_proc_info_t *pi,
int need_unwind_info, void *arg)
{
struct UPT_info *ui = arg;
unw_dyn_info_t *di;
int ret = -UNW_ENOINFO;
di = get_unwind_info (ui, as, ip);
if (!di)
if (get_unwind_info (ui, as, ip) < 0)
return -UNW_ENOINFO;
#if UNW_TARGET_IA64
if (di == &ui->ktab)
if (ui->ktab.format != -1)
{
/* The kernel unwind table resides in local memory, so we have
to use the local address space to search it. Since
@ -410,8 +425,8 @@ _UPT_find_proc_info (unw_addr_space_t as, unw_word_t ip, unw_proc_info_t *pi,
case, we simply make a copy of the unwind-info, so
_UPT_put_unwind_info() can always free() the unwind-info
without ill effects. */
int ret = tdep_search_unwind_table (unw_local_addr_space, ip, di, pi,
need_unwind_info, arg);
ret = tdep_search_unwind_table (unw_local_addr_space, ip, &ui->ktab, pi,
need_unwind_info, arg);
if (ret >= 0)
{
if (!need_unwind_info)
@ -426,9 +441,16 @@ _UPT_find_proc_info (unw_addr_space_t as, unw_word_t ip, unw_proc_info_t *pi,
pi->unwind_info = mem;
}
}
return ret;
}
else
#endif
return tdep_search_unwind_table (as, ip, di, pi, need_unwind_info, arg);
if (ret == -UNW_ENOINFO && ui->di_cache.format == -1)
ret = tdep_search_unwind_table (as, ip, &ui->di_cache,
pi, need_unwind_info, arg);
if (ret == -UNW_ENOINFO && ui->di_debug.format != -1)
ret = tdep_search_unwind_table (as, ip, &ui->di_debug, pi,
need_unwind_info, arg);
return ret;
}

13
src/ptrace/_UPT_internal.h
View file

@ -53,6 +53,7 @@ struct UPT_info
pid_t pid; /* the process-id of the child we're unwinding */
struct elf_image ei;
unw_dyn_info_t di_cache;
unw_dyn_info_t di_debug; /* additional table info for .debug_frame */
#if UNW_TARGET_IA64
unw_dyn_info_t ktab;
#endif
@ -60,11 +61,11 @@ struct UPT_info
extern int _UPT_reg_offset[UNW_REG_LAST + 1];
extern unw_dyn_info_t *_UPTi_find_unwind_table (struct UPT_info *ui,
unw_addr_space_t as,
char *path,
unw_word_t segbase,
unw_word_t mapoff,
unw_word_t ip);
extern int _UPTi_find_unwind_table (struct UPT_info *ui,
unw_addr_space_t as,
char *path,
unw_word_t segbase,
unw_word_t mapoff,
unw_word_t ip);
#endif /* _UPT_internal_h */