espressif/binutils-gdb
1
0
Fork 0
mirror of https://github.com/espressif/binutils-gdb.git synced 2025-08-06 14:49:38 +08:00
Code Issues Packages Projects Releases Wiki Activity

gdb, gdbserver: support dlmopen()

Browse Source 
In glibc, the r_debug structure contains (amongst others) the following
fields:

  int r_version:
    Version number for this protocol.  It should be greater than 0.

If r_version is 2, struct r_debug is extended to struct r_debug_extended
with one additional field:

  struct r_debug_extended *r_next;
    Link to the next r_debug_extended structure.  Each r_debug_extended
    structure represents a different namespace.  The first r_debug_extended
    structure is for the default namespace.

1. Change solib_svr4_r_map argument to take the debug base.
2. Add solib_svr4_r_next to find the link map in the next namespace from
the r_next field.
3. Update svr4_current_sos_direct to get the link map in the next namespace
from the r_next field.
4. Don't check shared libraries in other namespaces when updating shared
libraries in a new namespace.
5. Update svr4_same to check the load offset in addition to the name
6. Update svr4_default_sos to also set l_addr_inferior
7. Change the flat solib_list into a per-namespace list using the
namespace's r_debug address to identify the namespace.

Add gdb.base/dlmopen.exp to test this.

To remain backwards compatible with older gdbserver, we reserve the
namespace zero for a flat list of solibs from all namespaces.  Subsequent
patches will extend RSP to allow listing libraries grouped by namespace.

This fixes PR 11839.

Co-authored-by: Lu, Hongjiu  <hongjiu.lu@intel.com>
This commit is contained in:
Markus Metzger
2021-10-04 10:24:35 +02:00
parent 60d09f0a0d
commit 8d56636a0e
10 changed files with 793 additions and 186 deletions
Download Patch File Download Diff File Expand all files Collapse all files

249
gdbserver/linux-low.cc
View File

@ -6443,6 +6443,9 @@ struct link_map_offsets
/* Offset and size of r_debug.r_map. */
int r_map_offset;
/* Offset of r_debug_extended.r_next. */
int r_next_offset;
/* Offset to l_addr field in struct link_map. */
int l_addr_offset;
@ -6459,6 +6462,98 @@ struct link_map_offsets
int l_prev_offset;
};
static const link_map_offsets lmo_32bit_offsets =
{
0, /* r_version offset. */
4, /* r_debug.r_map offset. */
20, /* r_debug_extended.r_next. */
0, /* l_addr offset in link_map. */
4, /* l_name offset in link_map. */
8, /* l_ld offset in link_map. */
12, /* l_next offset in link_map. */
16 /* l_prev offset in link_map. */
};
static const link_map_offsets lmo_64bit_offsets =
{
0, /* r_version offset. */
8, /* r_debug.r_map offset. */
40, /* r_debug_extended.r_next. */
0, /* l_addr offset in link_map. */
8, /* l_name offset in link_map. */
16, /* l_ld offset in link_map. */
24, /* l_next offset in link_map. */
32 /* l_prev offset in link_map. */
};
/* Get the loaded shared libraries from one namespace. */
static void
read_link_map (std::string &document, CORE_ADDR lm_addr, CORE_ADDR lm_prev,
int ptr_size, const link_map_offsets *lmo, bool ignore_first,
int &header_done)
{
CORE_ADDR l_name, l_addr, l_ld, l_next, l_prev;
while (lm_addr
&& read_one_ptr (lm_addr + lmo->l_name_offset,
&l_name, ptr_size) == 0
&& read_one_ptr (lm_addr + lmo->l_addr_offset,
&l_addr, ptr_size) == 0
&& read_one_ptr (lm_addr + lmo->l_ld_offset,
&l_ld, ptr_size) == 0
&& read_one_ptr (lm_addr + lmo->l_prev_offset,
&l_prev, ptr_size) == 0
&& read_one_ptr (lm_addr + lmo->l_next_offset,
&l_next, ptr_size) == 0)
{
unsigned char libname[PATH_MAX];
if (lm_prev != l_prev)
{
warning ("Corrupted shared library list: 0x%s != 0x%s",
paddress (lm_prev), paddress (l_prev));
break;
}
/* Ignore the first entry even if it has valid name as the first entry
corresponds to the main executable. The first entry should not be
skipped if the dynamic loader was loaded late by a static executable
(see solib-svr4.c parameter ignore_first). But in such case the main
executable does not have PT_DYNAMIC present and this function already
exited above due to failed get_r_debug. */
if (ignore_first && lm_prev == 0)
string_appendf (document, " main-lm=\"0x%s\"", paddress (lm_addr));
else
{
/* Not checking for error because reading may stop before
we've got PATH_MAX worth of characters. */
libname[0] = '\0';
linux_read_memory (l_name, libname, sizeof (libname) - 1);
libname[sizeof (libname) - 1] = '\0';
if (libname[0] != '\0')
{
if (!header_done)
{
/* Terminate `<library-list-svr4'. */
document += '>';
header_done = 1;
}
string_appendf (document, "<library name=\"");
xml_escape_text_append (&document, (char *) libname);
string_appendf (document, "\" lm=\"0x%s\" l_addr=\"0x%s\" "
"l_ld=\"0x%s\"/>",
paddress (lm_addr), paddress (l_addr),
paddress (l_ld));
}
}
lm_prev = lm_addr;
lm_addr = l_next;
}
}
/* Construct qXfer:libraries-svr4:read reply. */
int
@ -6470,33 +6565,8 @@ linux_process_target::qxfer_libraries_svr4 (const char *annex,
struct process_info_private *const priv = current_process ()->priv;
char filename[PATH_MAX];
int pid, is_elf64;
static const struct link_map_offsets lmo_32bit_offsets =
{
0, /* r_version offset. */
4, /* r_debug.r_map offset. */
0, /* l_addr offset in link_map. */
4, /* l_name offset in link_map. */
8, /* l_ld offset in link_map. */
12, /* l_next offset in link_map. */
16 /* l_prev offset in link_map. */
};
static const struct link_map_offsets lmo_64bit_offsets =
{
0, /* r_version offset. */
8, /* r_debug.r_map offset. */
0, /* l_addr offset in link_map. */
8, /* l_name offset in link_map. */
16, /* l_ld offset in link_map. */
24, /* l_next offset in link_map. */
32 /* l_prev offset in link_map. */
};
const struct link_map_offsets *lmo;
unsigned int machine;
int ptr_size;
CORE_ADDR lm_addr = 0, lm_prev = 0;
CORE_ADDR l_name, l_addr, l_ld, l_next, l_prev;
int header_done = 0;
if (writebuf != NULL)
@ -6507,8 +6577,18 @@ linux_process_target::qxfer_libraries_svr4 (const char *annex,
pid = lwpid_of (current_thread);
xsnprintf (filename, sizeof filename, "/proc/%d/exe", pid);
is_elf64 = elf_64_file_p (filename, &machine);
lmo = is_elf64 ? &lmo_64bit_offsets : &lmo_32bit_offsets;
ptr_size = is_elf64 ? 8 : 4;
const link_map_offsets *lmo;
int ptr_size;
if (is_elf64)
{
lmo = &lmo_64bit_offsets;
ptr_size = 8;
}
else
{
lmo = &lmo_32bit_offsets;
ptr_size = 4;
}
while (annex[0] != '\0')
{
@ -6537,95 +6617,74 @@ linux_process_target::qxfer_libraries_svr4 (const char *annex,
annex = decode_address_to_semicolon (addrp, sep + 1);
}
if (lm_addr == 0)
{
int r_version = 0;
std::string document = "<library-list-svr4 version=\"1.0\"";
if (priv->r_debug == 0)
priv->r_debug = get_r_debug (pid, is_elf64);
/* When the starting LM_ADDR is passed in the annex, only traverse that
namespace.
Otherwise, start with R_DEBUG and traverse all namespaces we find. */
if (lm_addr != 0)
read_link_map (document, lm_addr, lm_prev, ptr_size, lmo, false,
header_done);
else
{
if (lm_prev != 0)
warning ("ignoring prev=0x%s without start", paddress (lm_prev));
CORE_ADDR r_debug = priv->r_debug;
if (r_debug == 0)
r_debug = priv->r_debug = get_r_debug (pid, is_elf64);
/* We failed to find DT_DEBUG. Such situation will not change
for this inferior - do not retry it. Report it to GDB as
E01, see for the reasons at the GDB solib-svr4.c side. */
if (priv->r_debug == (CORE_ADDR) -1)
if (r_debug == (CORE_ADDR) -1)
return -1;
if (priv->r_debug != 0)
bool ignore_first = true;
while (r_debug != 0)
{
if (linux_read_memory (priv->r_debug + lmo->r_version_offset,
int r_version = 0;
if (linux_read_memory (r_debug + lmo->r_version_offset,
(unsigned char *) &r_version,
sizeof (r_version)) != 0
|| r_version < 1)
sizeof (r_version)) != 0)
{
warning ("unable to read r_version from 0x%s",
paddress (r_debug + lmo->r_version_offset));
break;
}
if (r_version < 1)
{
warning ("unexpected r_debug version %d", r_version);
break;
}
else if (read_one_ptr (priv->r_debug + lmo->r_map_offset,
&lm_addr, ptr_size) != 0)
if (read_one_ptr (r_debug + lmo->r_map_offset, &lm_addr,
ptr_size) != 0)
{
warning ("unable to read r_map from 0x%lx",
(long) priv->r_debug + lmo->r_map_offset);
warning ("unable to read r_map from 0x%s",
paddress (r_debug + lmo->r_map_offset));
break;
}
}
}
std::string document = "<library-list-svr4 version=\"1.0\"";
read_link_map (document, lm_addr, 0, ptr_size, lmo,
ignore_first, header_done);
while (lm_addr
&& read_one_ptr (lm_addr + lmo->l_name_offset,
&l_name, ptr_size) == 0
&& read_one_ptr (lm_addr + lmo->l_addr_offset,
&l_addr, ptr_size) == 0
&& read_one_ptr (lm_addr + lmo->l_ld_offset,
&l_ld, ptr_size) == 0
&& read_one_ptr (lm_addr + lmo->l_prev_offset,
&l_prev, ptr_size) == 0
&& read_one_ptr (lm_addr + lmo->l_next_offset,
&l_next, ptr_size) == 0)
{
unsigned char libname[PATH_MAX];
if (r_version < 2)
break;
if (lm_prev != l_prev)
{
warning ("Corrupted shared library list: 0x%lx != 0x%lx",
(long) lm_prev, (long) l_prev);
break;
}
/* Only applies to the default namespace. */
ignore_first = false;
/* Ignore the first entry even if it has valid name as the first entry
corresponds to the main executable. The first entry should not be
skipped if the dynamic loader was loaded late by a static executable
(see solib-svr4.c parameter ignore_first). But in such case the main
executable does not have PT_DYNAMIC present and this function already
exited above due to failed get_r_debug. */
if (lm_prev == 0)
string_appendf (document, " main-lm=\"0x%lx\"", (unsigned long) lm_addr);
else
{
/* Not checking for error because reading may stop before
we've got PATH_MAX worth of characters. */
libname[0] = '\0';
linux_read_memory (l_name, libname, sizeof (libname) - 1);
libname[sizeof (libname) - 1] = '\0';
if (libname[0] != '\0')
if (read_one_ptr (r_debug + lmo->r_next_offset, &r_debug,
ptr_size) != 0)
{
if (!header_done)
{
/* Terminate `<library-list-svr4'. */
document += '>';
header_done = 1;
}
string_appendf (document, "<library name=\"");
xml_escape_text_append (&document, (char *) libname);
string_appendf (document, "\" lm=\"0x%lx\" "
"l_addr=\"0x%lx\" l_ld=\"0x%lx\"/>",
(unsigned long) lm_addr, (unsigned long) l_addr,
(unsigned long) l_ld);
warning ("unable to read r_next from 0x%s",
paddress (r_debug + lmo->r_next_offset));
break;
}
}
lm_prev = lm_addr;
lm_addr = l_next;
}
if (!header_done)