[PATCH v11 4/7] Move linux_find_memory_regions_full & co.

Jan Kratochvil
2015-07-23T17:22:01Z

This should be just a move with no changes.

gdb/ChangeLog
2015-07-15 Aleksandar Ristovski <aristovski@qnx.com
Jan Kratochvil <jan.kratochvil@redhat.com>

Move linux_find_memory_regions_full & co.
* linux-tdep.c (linux-maps.h): Include.
(gdb_regex.h): Remove the include.
(enum filterflags, struct smaps_vmflags, read_mapping, decode_vmflags)
(mapping_is_anonymous_p, dump_mapping_p): Moved to common/linux-maps.c.
(linux_find_memory_region_ftype): Moved typedef to common/linux-maps.h.
(linux_find_memory_regions_full): Moved definition to
common/linux-maps.c.
* common/linux-maps.c: Include ctype.h, target/target-utils.h,
gdb_regex.h and target/target.h.
(struct smaps_vmflags, read_mapping, decode_vmflags)
(mapping_is_anonymous_p, dump_mapping_p): Move from linux-tdep.c.
(linux_find_memory_regions_full): Move from linux-tdep.c.
* common/linux-maps.h (read_mapping): New declaration.
(linux_find_memory_region_ftype, enum filterflags): Moved from
linux-tdep.c.
(linux_find_memory_regions_full): New declaration.
* target.c (target/target-utils.h): Include.
(read_alloc_pread_ftype): Moved typedef to target/target-utils.h.
(read_alloc, read_stralloc_func_ftype, read_stralloc): Moved
definitions to target/target-utils.c.
* target.h (target_fileio_read_stralloc): Move it to target/target.h.
* target/target-utils.c (read_alloc, read_stralloc): Move definitions
from target.c.
* target/target-utils.h (read_alloc_pread_ftype): New typedef.
(read_alloc): New declaration.
(read_stralloc_func_ftype): New typedef.
(read_stralloc): New declaration.
* target/target.h (target_fileio_read_stralloc): Move it from target.h.

gdb/gdbserver/ChangeLog
2015-07-15 Aleksandar Ristovski <aristovski@qnx.com
Jan Kratochvil <jan.kratochvil@redhat.com>

* target.c: Include target/target-utils.h and fcntl.h.
(target_fileio_read_stralloc_1_pread, target_fileio_read_stralloc_1)
(target_fileio_read_stralloc): New functions.
---
gdb/common/linux-maps.c | 473 +++++++++++++++++++++++++++++++++++++++++++
gdb/common/linux-maps.h | 42 ++++
gdb/gdbserver/target.c | 36 +++
gdb/linux-tdep.c | 499 ---------------------------------------------
gdb/target.c | 91 --------
gdb/target.h | 10 -
gdb/target/target-utils.c | 79 +++++++
gdb/target/target-utils.h | 12 +
gdb/target/target.h | 11 +
9 files changed, 656 insertions(+), 597 deletions(-)

diff --git a/gdb/common/linux-maps.c b/gdb/common/linux-maps.c
index 01c8836..ef3da6a 100644
--- a/gdb/common/linux-maps.c
+++ b/gdb/common/linux-maps.c
@@ -18,3 +18,476 @@

#include "common-defs.h"
#include "linux-maps.h"
+#include <ctype.h>
+#include "target/target-utils.h"
+#include "gdb_regex.h"
+#include "target/target.h"
+
+/* This struct is used to map flags found in the "VmFlags:" field (in
+ the /proc/<PID>/smaps file). */
+
+struct smaps_vmflags
+ {
+ /* Zero if this structure has not been initialized yet. It
+ probably means that the Linux kernel being used does not emit
+ the "VmFlags:" field on "/proc/PID/smaps". */
+
+ unsigned int initialized_p : 1;
+
+ /* Memory mapped I/O area (VM_IO, "io"). */
+
+ unsigned int io_page : 1;
+
+ /* Area uses huge TLB pages (VM_HUGETLB, "ht"). */
+
+ unsigned int uses_huge_tlb : 1;
+
+ /* Do not include this memory region on the coredump (VM_DONTDUMP, "dd"). */
+
+ unsigned int exclude_coredump : 1;
+
+ /* Is this a MAP_SHARED mapping (VM_SHARED, "sh"). */
+
+ unsigned int shared_mapping : 1;
+ };
+
+/* Service function for corefiles and info proc. */
+
+void
+read_mapping (const char *line,
+ ULONGEST *addr, ULONGEST *endaddr,
+ const char **permissions, size_t *permissions_len,
+ ULONGEST *offset,
+ const char **device, size_t *device_len,
+ ULONGEST *inode,
+ const char **filename)
+{
+ const char *p = line;
+
+ *addr = strtoulst (p, &p, 16);
+ if (*p == '-')
+ p++;
+ *endaddr = strtoulst (p, &p, 16);
+
+ p = skip_spaces_const (p);
+ *permissions = p;
+ while (*p && !isspace (*p))
+ p++;
+ *permissions_len = p - *permissions;
+
+ *offset = strtoulst (p, &p, 16);
+
+ p = skip_spaces_const (p);
+ *device = p;
+ while (*p && !isspace (*p))
+ p++;
+ *device_len = p - *device;
+
+ *inode = strtoulst (p, &p, 10);
+
+ p = skip_spaces_const (p);
+ *filename = p;
+}
+
+/* Helper function to decode the "VmFlags" field in /proc/PID/smaps.
+
+ This function was based on the documentation found on
+ <Documentation/filesystems/proc.txt>, on the Linux kernel.
+
+ Linux kernels before commit
+ 834f82e2aa9a8ede94b17b656329f850c1471514 (3.10) do not have this
+ field on smaps. */
+
+static void
+decode_vmflags (char *p, struct smaps_vmflags *v)
+{
+ char *saveptr = NULL;
+ const char *s;
+
+ v->initialized_p = 1;
+ p = skip_to_space (p);
+ p = skip_spaces (p);
+
+ for (s = strtok_r (p, " ", &saveptr);
+ s != NULL;
+ s = strtok_r (NULL, " ", &saveptr))
+ {
+ if (strcmp (s, "io") == 0)
+ v->io_page = 1;
+ else if (strcmp (s, "ht") == 0)
+ v->uses_huge_tlb = 1;
+ else if (strcmp (s, "dd") == 0)
+ v->exclude_coredump = 1;
+ else if (strcmp (s, "sh") == 0)
+ v->shared_mapping = 1;
+ }
+}
+
+/* Return 1 if the memory mapping is anonymous, 0 otherwise.
+
+ FILENAME is the name of the file present in the first line of the
+ memory mapping, in the "/proc/PID/smaps" output. For example, if
+ the first line is:
+
+ 7fd0ca877000-7fd0d0da0000 r--p 00000000 fd:02 2100770 /path/to/file
+
+ Then FILENAME will be "/path/to/file". */
+
+static int
+mapping_is_anonymous_p (const char *filename)
+{
+ static regex_t dev_zero_regex, shmem_file_regex, file_deleted_regex;
+ static int init_regex_p = 0;
+
+ if (!init_regex_p)
+ {
+ struct cleanup *c = make_cleanup (null_cleanup, NULL);
+
+ /* Let's be pessimistic and assume there will be an error while
+ compiling the regex'es. */
+ init_regex_p = -1;
+
+ /* DEV_ZERO_REGEX matches "/dev/zero" filenames (with or
+ without the "(deleted)" string in the end). We know for
+ sure, based on the Linux kernel code, that memory mappings
+ whose associated filename is "/dev/zero" are guaranteed to be
+ MAP_ANONYMOUS. */
+ compile_rx_or_error (&dev_zero_regex, "^/dev/zero\\( (deleted)\\)\\?$",
+ _("Could not compile regex to match /dev/zero "
+ "filename"));
+ /* SHMEM_FILE_REGEX matches "/SYSV%08x" filenames (with or
+ without the "(deleted)" string in the end). These filenames
+ refer to shared memory (shmem), and memory mappings
+ associated with them are MAP_ANONYMOUS as well. */
+ compile_rx_or_error (&shmem_file_regex,
+ "^/\\?SYSV[0-9a-fA-F]\\{8\\}\\( (deleted)\\)\\?$",
+ _("Could not compile regex to match shmem "
+ "filenames"));
+ /* FILE_DELETED_REGEX is a heuristic we use to try to mimic the
+ Linux kernel's 'n_link == 0' code, which is responsible to
+ decide if it is dealing with a 'MAP_SHARED | MAP_ANONYMOUS'
+ mapping. In other words, if FILE_DELETED_REGEX matches, it
+ does not necessarily mean that we are dealing with an
+ anonymous shared mapping. However, there is no easy way to
+ detect this currently, so this is the best approximation we
+ have.
+
+ As a result, GDB will dump readonly pages of deleted
+ executables when using the default value of coredump_filter
+ (0x33), while the Linux kernel will not dump those pages.
+ But we can live with that. */
+ compile_rx_or_error (&file_deleted_regex, " (deleted)$",
+ _("Could not compile regex to match "
+ "'<file> (deleted)'"));
+ /* We will never release these regexes, so just discard the
+ cleanups. */
+ discard_cleanups (c);
+
+ /* If we reached this point, then everything succeeded. */
+ init_regex_p = 1;
+ }
+
+ if (init_regex_p == -1)
+ {
+ const char deleted[] = " (deleted)";
+ size_t del_len = sizeof (deleted) - 1;
+ size_t filename_len = strlen (filename);
+
+ /* There was an error while compiling the regex'es above. In
+ order to try to give some reliable information to the caller,
+ we just try to find the string " (deleted)" in the filename.
+ If we managed to find it, then we assume the mapping is
+ anonymous. */
+ return (filename_len >= del_len
+ && strcmp (filename + filename_len - del_len, deleted) == 0);
+ }
+
+ if (*filename == '\0'
+ || regexec (&dev_zero_regex, filename, 0, NULL, 0) == 0
+ || regexec (&shmem_file_regex, filename, 0, NULL, 0) == 0
+ || regexec (&file_deleted_regex, filename, 0, NULL, 0) == 0)
+ return 1;
+
+ return 0;
+}
+
+/* Return 0 if the memory mapping (which is related to FILTERFLAGS, V,
+ MAYBE_PRIVATE_P, and MAPPING_ANONYMOUS_P) should not be dumped, or
+ greater than 0 if it should.
+
+ In a nutshell, this is the logic that we follow in order to decide
+ if a mapping should be dumped or not.
+
+ - If the mapping is associated to a file whose name ends with
+ " (deleted)", or if the file is "/dev/zero", or if it is
+ "/SYSV%08x" (shared memory), or if there is no file associated
+ with it, or if the AnonHugePages: or the Anonymous: fields in the
+ /proc/PID/smaps have contents, then GDB considers this mapping to
+ be anonymous. Otherwise, GDB considers this mapping to be a
+ file-backed mapping (because there will be a file associated with
+ it).
+
+ It is worth mentioning that, from all those checks described
+ above, the most fragile is the one to see if the file name ends
+ with " (deleted)". This does not necessarily mean that the
+ mapping is anonymous, because the deleted file associated with
+ the mapping may have been a hard link to another file, for
+ example. The Linux kernel checks to see if "i_nlink == 0", but
+ GDB cannot easily (and normally) do this check (iff running as
+ root, it could find the mapping in /proc/PID/map_files/ and
+ determine whether there still are other hard links to the
+ inode/file). Therefore, we made a compromise here, and we assume
+ that if the file name ends with " (deleted)", then the mapping is
+ indeed anonymous. FWIW, this is something the Linux kernel could
+ do better: expose this information in a more direct way.
+
+ - If we see the flag "sh" in the "VmFlags:" field (in
+ /proc/PID/smaps), then certainly the memory mapping is shared
+ (VM_SHARED). If we have access to the VmFlags, and we don't see
+ the "sh" there, then certainly the mapping is private. However,
+ Linux kernels before commit
+ 834f82e2aa9a8ede94b17b656329f850c1471514 (3.10) do not have the
+ "VmFlags:" field; in that case, we use another heuristic: if we
+ see 'p' in the permission flags, then we assume that the mapping
+ is private, even though the presence of the 's' flag there would
+ mean VM_MAYSHARE, which means the mapping could still be private.
+ This should work OK enough, however. */
+
+static int
+dump_mapping_p (enum filterflags filterflags, const struct smaps_vmflags *v,
+ int maybe_private_p, int mapping_anon_p, int mapping_file_p,
+ const char *filename)
+{
+ /* Initially, we trust in what we received from our caller. This
+ value may not be very precise (i.e., it was probably gathered
+ from the permission line in the /proc/PID/smaps list, which
+ actually refers to VM_MAYSHARE, and not VM_SHARED), but it is
+ what we have until we take a look at the "VmFlags:" field
+ (assuming that the version of the Linux kernel being used
+ supports it, of course). */
+ int private_p = maybe_private_p;
+
+ /* We always dump vDSO and vsyscall mappings, because it's likely that
+ there'll be no file to read the contents from at core load time.
+ The kernel does the same. */
+ if (strcmp ("[vdso]", filename) == 0
+ || strcmp ("[vsyscall]", filename) == 0)
+ return 1;
+
+ if (v->initialized_p)
+ {
+ /* We never dump I/O mappings. */
+ if (v->io_page)
+ return 0;
+
+ /* Check if we should exclude this mapping. */
+ if (v->exclude_coredump)
+ return 0;
+
+ /* Update our notion of whether this mapping is shared or
+ private based on a trustworthy value. */
+ private_p = !v->shared_mapping;
+
+ /* HugeTLB checking. */
+ if (v->uses_huge_tlb)
+ {
+ if ((private_p && (filterflags & COREFILTER_HUGETLB_PRIVATE))
+ || (!private_p && (filterflags & COREFILTER_HUGETLB_SHARED)))
+ return 1;
+
+ return 0;
+ }
+ }
+
+ if (private_p)
+ {
+ if (mapping_anon_p && mapping_file_p)
+ {
+ /* This is a special situation. It can happen when we see a
+ mapping that is file-backed, but that contains anonymous
+ pages. */
+ return ((filterflags & COREFILTER_ANON_PRIVATE) != 0
+ || (filterflags & COREFILTER_MAPPED_PRIVATE) != 0);
+ }
+ else if (mapping_anon_p)
+ return (filterflags & COREFILTER_ANON_PRIVATE) != 0;
+ else
+ return (filterflags & COREFILTER_MAPPED_PRIVATE) != 0;
+ }
+ else
+ {
+ if (mapping_anon_p && mapping_file_p)
+ {
+ /* This is a special situation. It can happen when we see a
+ mapping that is file-backed, but that contains anonymous
+ pages. */
+ return ((filterflags & COREFILTER_ANON_SHARED) != 0
+ || (filterflags & COREFILTER_MAPPED_SHARED) != 0);
+ }
+ else if (mapping_anon_p)
+ return (filterflags & COREFILTER_ANON_SHARED) != 0;
+ else
+ return (filterflags & COREFILTER_MAPPED_SHARED) != 0;
+ }
+}
+
+/* List memory regions in the inferior PID matched to FILTERFLAGS for
+ a corefile. Call FUNC with FUNC_DATA for each such region. Return
+ immediately with the value returned by FUNC if it is non-zero.
+ *MEMORY_TO_FREE_PTR should be registered to be freed automatically if
+ called FUNC throws an exception. MEMORY_TO_FREE_PTR can be also
+ passed as NULL if it is not used. Return -1 if error occurs, 0 if
+ all memory regions have been processed or return the value from FUNC
+ if FUNC returns non-zero. */
+
+int
+linux_find_memory_regions_full (pid_t pid, enum filterflags filterflags,
+ linux_find_memory_region_ftype *func,
+ void *func_data)
+{
+ char mapsfilename[100];
+ char *data;
+
+ xsnprintf (mapsfilename, sizeof mapsfilename, "/proc/%d/smaps", pid);
+ data = target_fileio_read_stralloc (NULL, mapsfilename);
+ if (data == NULL)
+ {
+ /* Older Linux kernels did not support /proc/PID/smaps. */
+ xsnprintf (mapsfilename, sizeof mapsfilename, "/proc/%d/maps", pid);
+ data = target_fileio_read_stralloc (NULL, mapsfilename);
+ }
+
+ if (data != NULL)
+ {
+ struct cleanup *cleanup = make_cleanup (xfree, data);
+ char *line, *t;
+ int retval = 0;
+
+ line = strtok_r (data, "\n", &t);
+ while (line != NULL)
+ {
+ ULONGEST addr, endaddr, offset, inode;
+ const char *permissions, *device, *filename;
+ struct smaps_vmflags v;
+ size_t permissions_len, device_len;
+ int read, write, exec, priv;
+ int has_anonymous = 0;
+ int should_dump_p = 0;
+ int mapping_anon_p;
+ int mapping_file_p;
+
+ memset (&v, 0, sizeof (v));
+ read_mapping (line, &addr, &endaddr, &permissions, &permissions_len,
+ &offset, &device, &device_len, &inode, &filename);
+ mapping_anon_p = mapping_is_anonymous_p (filename);
+ /* If the mapping is not anonymous, then we can consider it
+ to be file-backed. These two states (anonymous or
+ file-backed) seem to be exclusive, but they can actually
+ coexist. For example, if a file-backed mapping has
+ "Anonymous:" pages (see more below), then the Linux
+ kernel will dump this mapping when the user specified
+ that she only wants anonymous mappings in the corefile
+ (*even* when she explicitly disabled the dumping of
+ file-backed mappings). */
+ mapping_file_p = !mapping_anon_p;
+
+ /* Decode permissions. */
+ read = (memchr (permissions, 'r', permissions_len) != 0);
+ write = (memchr (permissions, 'w', permissions_len) != 0);
+ exec = (memchr (permissions, 'x', permissions_len) != 0);
+ /* 'private' here actually means VM_MAYSHARE, and not
+ VM_SHARED. In order to know if a mapping is really
+ private or not, we must check the flag "sh" in the
+ VmFlags field. This is done by decode_vmflags. However,
+ if we are using a Linux kernel released before the commit
+ 834f82e2aa9a8ede94b17b656329f850c1471514 (3.10), we will
+ not have the VmFlags there. In this case, there is
+ really no way to know if we are dealing with VM_SHARED,
+ so we just assume that VM_MAYSHARE is enough. */
+ priv = memchr (permissions, 'p', permissions_len) != 0;
+
+ /* Try to detect if region should be dumped by parsing smaps
+ counters. */
+ for (line = strtok_r (NULL, "\n", &t);
+ line != NULL && line[0] >= 'A' && line[0] <= 'Z';
+ line = strtok_r (NULL, "\n", &t))
+ {
+ char keyword[64 + 1];
+
+ if (sscanf (line, "%64s", keyword) != 1)
+ {
+ warning (_("Error parsing {s,}maps file '%s'"), mapsfilename);
+ break;
+ }
+
+ if (strcmp (keyword, "Anonymous:") == 0)
+ {
+ /* Older Linux kernels did not support the
+ "Anonymous:" counter. Check it here. */
+ has_anonymous = 1;
+ }
+ else if (strcmp (keyword, "VmFlags:") == 0)
+ decode_vmflags (line, &v);
+
+ if (strcmp (keyword, "AnonHugePages:") == 0
+ || strcmp (keyword, "Anonymous:") == 0)
+ {
+ unsigned long number;
+
+ if (sscanf (line, "%*s%lu", &number) != 1)
+ {
+ warning (_("Error parsing {s,}maps file '%s' number"),
+ mapsfilename);
+ break;
+ }
+ if (number > 0)
+ {
+ /* Even if we are dealing with a file-backed
+ mapping, if it contains anonymous pages we
+ consider it to be *also* an anonymous
+ mapping, because this is what the Linux
+ kernel does:
+
+ // Dump segments that have been written to.
+ if (vma->anon_vma && FILTER(ANON_PRIVATE))
+ goto whole;
+
+ Note that if the mapping is already marked as
+ file-backed (i.e., mapping_file_p is
+ non-zero), then this is a special case, and
+ this mapping will be dumped either when the
+ user wants to dump file-backed *or* anonymous
+ mappings. */
+ mapping_anon_p = 1;
+ }
+ }
+ }
+
+ if (has_anonymous)
+ should_dump_p = dump_mapping_p (filterflags, &v, priv,
+ mapping_anon_p, mapping_file_p,
+ filename);
+ else
+ {
+ /* Older Linux kernels did not support the "Anonymous:" counter.
+ If it is missing, we can't be sure - dump all the pages. */
+ should_dump_p = 1;
+ }
+
+ /* Invoke the callback function to create the corefile segment. */
+ if (should_dump_p)
+ retval = func (addr, endaddr - addr, offset, inode,
+ read, write, exec,
+ 1, /* MODIFIED is true because we want to dump the
+ mapping. */
+ filename, func_data);
+ if (retval != 0)
+ break;
+ }
+
+ do_cleanups (cleanup);
+ return retval;
+ }
+
+ return -1;
+}
diff --git a/gdb/common/linux-maps.h b/gdb/common/linux-maps.h
index 4228674..0bec9db 100644
--- a/gdb/common/linux-maps.h
+++ b/gdb/common/linux-maps.h
@@ -19,4 +19,46 @@
#ifndef COMMON_LINUX_MAPS_H
#define COMMON_LINUX_MAPS_H

+extern void
+ read_mapping (const char *line,
+ ULONGEST *addr, ULONGEST *endaddr,
+ const char **permissions, size_t *permissions_len,
+ ULONGEST *offset,
+ const char **device, size_t *device_len,
+ ULONGEST *inode,
+ const char **filename);
+
+/* Callback function for linux_find_memory_regions_full. If it returns
+ non-zero linux_find_memory_regions_full returns immediately with that
+ value. */
+
+typedef int linux_find_memory_region_ftype (ULONGEST vaddr, ULONGEST size,
+ ULONGEST offset, ULONGEST inode,
+ int read, int write,
+ int exec, int modified,
+ const char *filename,
+ void *data);
+
+/* This enum represents the values that the user can choose when
+ informing the Linux kernel about which memory mappings will be
+ dumped in a corefile. They are described in the file
+ Documentation/filesystems/proc.txt, inside the Linux kernel
+ tree. */
+
+enum filterflags
+ {
+ COREFILTER_ANON_PRIVATE = 1 << 0,
+ COREFILTER_ANON_SHARED = 1 << 1,
+ COREFILTER_MAPPED_PRIVATE = 1 << 2,
+ COREFILTER_MAPPED_SHARED = 1 << 3,
+ COREFILTER_ELF_HEADERS = 1 << 4,
+ COREFILTER_HUGETLB_PRIVATE = 1 << 5,
+ COREFILTER_HUGETLB_SHARED = 1 << 6,
+ };
+
+extern int
+ linux_find_memory_regions_full (pid_t pid, enum filterflags filterflags,
+ linux_find_memory_region_ftype *func,
+ void *func_data);
+
#endif /* COMMON_LINUX_MAPS_H */
diff --git a/gdb/gdbserver/target.c b/gdb/gdbserver/target.c
index 14999e6..5525b1f 100644
--- a/gdb/gdbserver/target.c
+++ b/gdb/gdbserver/target.c
@@ -20,6 +20,8 @@

#include "server.h"
#include "tracepoint.h"
+#include "target/target-utils.h"
+#include <fcntl.h>

struct target_ops *the_target;

@@ -218,3 +220,37 @@ kill_inferior (int pid)

return (*the_target->kill) (pid);
}
+
+static int
+target_fileio_read_stralloc_1_pread (int handle, gdb_byte *read_buf, int len,
+ ULONGEST offset, int *target_errno)
+{
+ int retval = pread (handle, read_buf, len, offset);
+
+ *target_errno = errno;
+ return retval;
+}
+
+static LONGEST
+target_fileio_read_stralloc_1 (struct inferior *inf, const char *filename,
+ gdb_byte **buf_p, int padding)
+{
+ int fd;
+ LONGEST retval;
+
+ fd = open (filename, O_RDONLY);
+ if (fd == -1)
+ return -1;
+
+ retval = read_alloc (buf_p, fd, target_fileio_read_stralloc_1_pread, padding);
+
+ close (fd);
+
+ return retval;
+}
+
+char *
+target_fileio_read_stralloc (struct inferior *inf, const char *filename)
+{
+ return read_stralloc (inf, filename, target_fileio_read_stralloc_1);
+}
diff --git a/gdb/linux-tdep.c b/gdb/linux-tdep.c
index 982599e..3df86ba 100644
--- a/gdb/linux-tdep.c
+++ b/gdb/linux-tdep.c
@@ -35,56 +35,11 @@
#include "observer.h"
#include "objfiles.h"
#include "infcall.h"
+#include "linux-maps.h"
#include "gdbcmd.h"
-#include "gdb_regex.h"

#include <ctype.h>

-/* This enum represents the values that the user can choose when
- informing the Linux kernel about which memory mappings will be
- dumped in a corefile. They are described in the file
- Documentation/filesystems/proc.txt, inside the Linux kernel
- tree. */
-
-enum filterflags
- {
- COREFILTER_ANON_PRIVATE = 1 << 0,
- COREFILTER_ANON_SHARED = 1 << 1,
- COREFILTER_MAPPED_PRIVATE = 1 << 2,
- COREFILTER_MAPPED_SHARED = 1 << 3,
- COREFILTER_ELF_HEADERS = 1 << 4,
- COREFILTER_HUGETLB_PRIVATE = 1 << 5,
- COREFILTER_HUGETLB_SHARED = 1 << 6,
- };
-
-/* This struct is used to map flags found in the "VmFlags:" field (in
- the /proc/<PID>/smaps file). */
-
-struct smaps_vmflags
- {
- /* Zero if this structure has not been initialized yet. It
- probably means that the Linux kernel being used does not emit
- the "VmFlags:" field on "/proc/PID/smaps". */
-
- unsigned int initialized_p : 1;
-
- /* Memory mapped I/O area (VM_IO, "io"). */
-
- unsigned int io_page : 1;
-
- /* Area uses huge TLB pages (VM_HUGETLB, "ht"). */
-
- unsigned int uses_huge_tlb : 1;
-
- /* Do not include this memory region on the coredump (VM_DONTDUMP, "dd"). */
-
- unsigned int exclude_coredump : 1;
-
- /* Is this a MAP_SHARED mapping (VM_SHARED, "sh"). */
-
- unsigned int shared_mapping : 1;
- };
-
/* Whether to take the /proc/PID/coredump_filter into account when
generating a corefile. */

@@ -395,286 +350,6 @@ linux_core_pid_to_str (struct gdbarch *gdbarch, ptid_t ptid)
return normal_pid_to_str (ptid);
}

-/* Service function for corefiles and info proc. */
-
-static void
-read_mapping (const char *line,
- ULONGEST *addr, ULONGEST *endaddr,
- const char **permissions, size_t *permissions_len,
- ULONGEST *offset,
- const char **device, size_t *device_len,
- ULONGEST *inode,
- const char **filename)
-{
- const char *p = line;
-
- *addr = strtoulst (p, &p, 16);
- if (*p == '-')
- p++;
- *endaddr = strtoulst (p, &p, 16);
-
- p = skip_spaces_const (p);
- *permissions = p;
- while (*p && !isspace (*p))
- p++;
- *permissions_len = p - *permissions;
-
- *offset = strtoulst (p, &p, 16);
-
- p = skip_spaces_const (p);
- *device = p;
- while (*p && !isspace (*p))
- p++;
- *device_len = p - *device;
-
- *inode = strtoulst (p, &p, 10);
-
- p = skip_spaces_const (p);
- *filename = p;
-}
-
-/* Helper function to decode the "VmFlags" field in /proc/PID/smaps.
-
- This function was based on the documentation found on
- <Documentation/filesystems/proc.txt>, on the Linux kernel.
-
- Linux kernels before commit
- 834f82e2aa9a8ede94b17b656329f850c1471514 (3.10) do not have this
- field on smaps. */
-
-static void
-decode_vmflags (char *p, struct smaps_vmflags *v)
-{
- char *saveptr = NULL;
- const char *s;
-
- v->initialized_p = 1;
- p = skip_to_space (p);
- p = skip_spaces (p);
-
- for (s = strtok_r (p, " ", &saveptr);
- s != NULL;
- s = strtok_r (NULL, " ", &saveptr))
- {
- if (strcmp (s, "io") == 0)
- v->io_page = 1;
- else if (strcmp (s, "ht") == 0)
- v->uses_huge_tlb = 1;
- else if (strcmp (s, "dd") == 0)
- v->exclude_coredump = 1;
- else if (strcmp (s, "sh") == 0)
- v->shared_mapping = 1;
- }
-}
-
-/* Return 1 if the memory mapping is anonymous, 0 otherwise.
-
- FILENAME is the name of the file present in the first line of the
- memory mapping, in the "/proc/PID/smaps" output. For example, if
- the first line is:
-
- 7fd0ca877000-7fd0d0da0000 r--p 00000000 fd:02 2100770 /path/to/file
-
- Then FILENAME will be "/path/to/file". */
-
-static int
-mapping_is_anonymous_p (const char *filename)
-{
- static regex_t dev_zero_regex, shmem_file_regex, file_deleted_regex;
- static int init_regex_p = 0;
-
- if (!init_regex_p)
- {
- struct cleanup *c = make_cleanup (null_cleanup, NULL);
-
- /* Let's be pessimistic and assume there will be an error while
- compiling the regex'es. */
- init_regex_p = -1;
-
- /* DEV_ZERO_REGEX matches "/dev/zero" filenames (with or
- without the "(deleted)" string in the end). We know for
- sure, based on the Linux kernel code, that memory mappings
- whose associated filename is "/dev/zero" are guaranteed to be
- MAP_ANONYMOUS. */
- compile_rx_or_error (&dev_zero_regex, "^/dev/zero\\( (deleted)\\)\\?$",
- _("Could not compile regex to match /dev/zero "
- "filename"));
- /* SHMEM_FILE_REGEX matches "/SYSV%08x" filenames (with or
- without the "(deleted)" string in the end). These filenames
- refer to shared memory (shmem), and memory mappings
- associated with them are MAP_ANONYMOUS as well. */
- compile_rx_or_error (&shmem_file_regex,
- "^/\\?SYSV[0-9a-fA-F]\\{8\\}\\( (deleted)\\)\\?$",
- _("Could not compile regex to match shmem "
- "filenames"));
- /* FILE_DELETED_REGEX is a heuristic we use to try to mimic the
- Linux kernel's 'n_link == 0' code, which is responsible to
- decide if it is dealing with a 'MAP_SHARED | MAP_ANONYMOUS'
- mapping. In other words, if FILE_DELETED_REGEX matches, it
- does not necessarily mean that we are dealing with an
- anonymous shared mapping. However, there is no easy way to
- detect this currently, so this is the best approximation we
- have.
-
- As a result, GDB will dump readonly pages of deleted
- executables when using the default value of coredump_filter
- (0x33), while the Linux kernel will not dump those pages.
- But we can live with that. */
- compile_rx_or_error (&file_deleted_regex, " (deleted)$",
- _("Could not compile regex to match "
- "'<file> (deleted)'"));
- /* We will never release these regexes, so just discard the
- cleanups. */
- discard_cleanups (c);
-
- /* If we reached this point, then everything succeeded. */
- init_regex_p = 1;
- }
-
- if (init_regex_p == -1)
- {
- const char deleted[] = " (deleted)";
- size_t del_len = sizeof (deleted) - 1;
- size_t filename_len = strlen (filename);
-
- /* There was an error while compiling the regex'es above. In
- order to try to give some reliable information to the caller,
- we just try to find the string " (deleted)" in the filename.
- If we managed to find it, then we assume the mapping is
- anonymous. */
- return (filename_len >= del_len
- && strcmp (filename + filename_len - del_len, deleted) == 0);
- }
-
- if (*filename == '\0'
- || regexec (&dev_zero_regex, filename, 0, NULL, 0) == 0
- || regexec (&shmem_file_regex, filename, 0, NULL, 0) == 0
- || regexec (&file_deleted_regex, filename, 0, NULL, 0) == 0)
- return 1;
-
- return 0;
-}
-
-/* Return 0 if the memory mapping (which is related to FILTERFLAGS, V,
- MAYBE_PRIVATE_P, and MAPPING_ANONYMOUS_P) should not be dumped, or
- greater than 0 if it should.
-
- In a nutshell, this is the logic that we follow in order to decide
- if a mapping should be dumped or not.
-
- - If the mapping is associated to a file whose name ends with
- " (deleted)", or if the file is "/dev/zero", or if it is
- "/SYSV%08x" (shared memory), or if there is no file associated
- with it, or if the AnonHugePages: or the Anonymous: fields in the
- /proc/PID/smaps have contents, then GDB considers this mapping to
- be anonymous. Otherwise, GDB considers this mapping to be a
- file-backed mapping (because there will be a file associated with
- it).
-
- It is worth mentioning that, from all those checks described
- above, the most fragile is the one to see if the file name ends
- with " (deleted)". This does not necessarily mean that the
- mapping is anonymous, because the deleted file associated with
- the mapping may have been a hard link to another file, for
- example. The Linux kernel checks to see if "i_nlink == 0", but
- GDB cannot easily (and normally) do this check (iff running as
- root, it could find the mapping in /proc/PID/map_files/ and
- determine whether there still are other hard links to the
- inode/file). Therefore, we made a compromise here, and we assume
- that if the file name ends with " (deleted)", then the mapping is
- indeed anonymous. FWIW, this is something the Linux kernel could
- do better: expose this information in a more direct way.
-
- - If we see the flag "sh" in the "VmFlags:" field (in
- /proc/PID/smaps), then certainly the memory mapping is shared
- (VM_SHARED). If we have access to the VmFlags, and we don't see
- the "sh" there, then certainly the mapping is private. However,
- Linux kernels before commit
- 834f82e2aa9a8ede94b17b656329f850c1471514 (3.10) do not have the
- "VmFlags:" field; in that case, we use another heuristic: if we
- see 'p' in the permission flags, then we assume that the mapping
- is private, even though the presence of the 's' flag there would
- mean VM_MAYSHARE, which means the mapping could still be private.
- This should work OK enough, however. */
-
-static int
-dump_mapping_p (enum filterflags filterflags, const struct smaps_vmflags *v,
- int maybe_private_p, int mapping_anon_p, int mapping_file_p,
- const char *filename)
-{
- /* Initially, we trust in what we received from our caller. This
- value may not be very precise (i.e., it was probably gathered
- from the permission line in the /proc/PID/smaps list, which
- actually refers to VM_MAYSHARE, and not VM_SHARED), but it is
- what we have until we take a look at the "VmFlags:" field
- (assuming that the version of the Linux kernel being used
- supports it, of course). */
- int private_p = maybe_private_p;
-
- /* We always dump vDSO and vsyscall mappings, because it's likely that
- there'll be no file to read the contents from at core load time.
- The kernel does the same. */
- if (strcmp ("[vdso]", filename) == 0
- || strcmp ("[vsyscall]", filename) == 0)
- return 1;
-
- if (v->initialized_p)
- {
- /* We never dump I/O mappings. */
- if (v->io_page)
- return 0;
-
- /* Check if we should exclude this mapping. */
- if (v->exclude_coredump)
- return 0;
-
- /* Update our notion of whether this mapping is shared or
- private based on a trustworthy value. */
- private_p = !v->shared_mapping;
-
- /* HugeTLB checking. */
- if (v->uses_huge_tlb)
- {
- if ((private_p && (filterflags & COREFILTER_HUGETLB_PRIVATE))
- || (!private_p && (filterflags & COREFILTER_HUGETLB_SHARED)))
- return 1;
-
- return 0;
- }
- }
-
- if (private_p)
- {
- if (mapping_anon_p && mapping_file_p)
- {
- /* This is a special situation. It can happen when we see a
- mapping that is file-backed, but that contains anonymous
- pages. */
- return ((filterflags & COREFILTER_ANON_PRIVATE) != 0
- || (filterflags & COREFILTER_MAPPED_PRIVATE) != 0);
- }
- else if (mapping_anon_p)
- return (filterflags & COREFILTER_ANON_PRIVATE) != 0;
- else
- return (filterflags & COREFILTER_MAPPED_PRIVATE) != 0;
- }
- else
- {
- if (mapping_anon_p && mapping_file_p)
- {
- /* This is a special situation. It can happen when we see a
- mapping that is file-backed, but that contains anonymous
- pages. */
- return ((filterflags & COREFILTER_ANON_SHARED) != 0
- || (filterflags & COREFILTER_MAPPED_SHARED) != 0);
- }
- else if (mapping_anon_p)
- return (filterflags & COREFILTER_ANON_SHARED) != 0;
- else
- return (filterflags & COREFILTER_MAPPED_SHARED) != 0;
- }
-}
-
/* Implement the "info proc" command. */

static void
@@ -1098,178 +773,6 @@ linux_core_info_proc (struct gdbarch *gdbarch, const char *args,
error (_("unable to handle request"));
}

-/* Callback function for linux_find_memory_regions_full. If it returns
- non-zero linux_find_memory_regions_full returns immediately with that
- value. */
-
-typedef int linux_find_memory_region_ftype (ULONGEST vaddr, ULONGEST size,
- ULONGEST offset, ULONGEST inode,
- int read, int write,
- int exec, int modified,
- const char *filename,
- void *data);
-
-/* List memory regions in the inferior PID matched to FILTERFLAGS for
- a corefile. Call FUNC with FUNC_DATA for each such region. Return
- immediately with the value returned by FUNC if it is non-zero.
- *MEMORY_TO_FREE_PTR should be registered to be freed automatically if
- called FUNC throws an exception. MEMORY_TO_FREE_PTR can be also
- passed as NULL if it is not used. Return -1 if error occurs, 0 if
- all memory regions have been processed or return the value from FUNC
- if FUNC returns non-zero. */
-
-static int
-linux_find_memory_regions_full (pid_t pid, enum filterflags filterflags,
- linux_find_memory_region_ftype *func,
- void *func_data)
-{
- char mapsfilename[100];
- char *data;
-
- xsnprintf (mapsfilename, sizeof mapsfilename, "/proc/%d/smaps", pid);
- data = target_fileio_read_stralloc (NULL, mapsfilename);
- if (data == NULL)
- {
- /* Older Linux kernels did not support /proc/PID/smaps. */
- xsnprintf (mapsfilename, sizeof mapsfilename, "/proc/%d/maps", pid);
- data = target_fileio_read_stralloc (NULL, mapsfilename);
- }
-
- if (data != NULL)
- {
- struct cleanup *cleanup = make_cleanup (xfree, data);
- char *line, *t;
- int retval = 0;
-
- line = strtok_r (data, "\n", &t);
- while (line != NULL)
- {
- ULONGEST addr, endaddr, offset, inode;
- const char *permissions, *device, *filename;
- struct smaps_vmflags v;
- size_t permissions_len, device_len;
- int read, write, exec, priv;
- int has_anonymous = 0;
- int should_dump_p = 0;
- int mapping_anon_p;
- int mapping_file_p;
-
- memset (&v, 0, sizeof (v));
- read_mapping (line, &addr, &endaddr, &permissions, &permissions_len,
- &offset, &device, &device_len, &inode, &filename);
- mapping_anon_p = mapping_is_anonymous_p (filename);
- /* If the mapping is not anonymous, then we can consider it
- to be file-backed. These two states (anonymous or
- file-backed) seem to be exclusive, but they can actually
- coexist. For example, if a file-backed mapping has
- "Anonymous:" pages (see more below), then the Linux
- kernel will dump this mapping when the user specified
- that she only wants anonymous mappings in the corefile
- (*even* when she explicitly disabled the dumping of
- file-backed mappings). */
- mapping_file_p = !mapping_anon_p;
-
- /* Decode permissions. */
- read = (memchr (permissions, 'r', permissions_len) != 0);
- write = (memchr (permissions, 'w', permissions_len) != 0);
- exec = (memchr (permissions, 'x', permissions_len) != 0);
- /* 'private' here actually means VM_MAYSHARE, and not
- VM_SHARED. In order to know if a mapping is really
- private or not, we must check the flag "sh" in the
- VmFlags field. This is done by decode_vmflags. However,
- if we are using a Linux kernel released before the commit
- 834f82e2aa9a8ede94b17b656329f850c1471514 (3.10), we will
- not have the VmFlags there. In this case, there is
- really no way to know if we are dealing with VM_SHARED,
- so we just assume that VM_MAYSHARE is enough. */
- priv = memchr (permissions, 'p', permissions_len) != 0;
-
- /* Try to detect if region should be dumped by parsing smaps
- counters. */
- for (line = strtok_r (NULL, "\n", &t);
- line != NULL && line[0] >= 'A' && line[0] <= 'Z';
- line = strtok_r (NULL, "\n", &t))
- {
- char keyword[64 + 1];
-
- if (sscanf (line, "%64s", keyword) != 1)
- {
- warning (_("Error parsing {s,}maps file '%s'"), mapsfilename);
- break;
- }
-
- if (strcmp (keyword, "Anonymous:") == 0)
- {
- /* Older Linux kernels did not support the
- "Anonymous:" counter. Check it here. */
- has_anonymous = 1;
- }
- else if (strcmp (keyword, "VmFlags:") == 0)
- decode_vmflags (line, &v);
-
- if (strcmp (keyword, "AnonHugePages:") == 0
- || strcmp (keyword, "Anonymous:") == 0)
- {
- unsigned long number;
-
- if (sscanf (line, "%*s%lu", &number) != 1)
- {
- warning (_("Error parsing {s,}maps file '%s' number"),
- mapsfilename);
- break;
- }
- if (number > 0)
- {
- /* Even if we are dealing with a file-backed
- mapping, if it contains anonymous pages we
- consider it to be *also* an anonymous
- mapping, because this is what the Linux
- kernel does:
-
- // Dump segments that have been written to.
- if (vma->anon_vma && FILTER(ANON_PRIVATE))
- goto whole;
-
- Note that if the mapping is already marked as
- file-backed (i.e., mapping_file_p is
- non-zero), then this is a special case, and
- this mapping will be dumped either when the
- user wants to dump file-backed *or* anonymous
- mappings. */
- mapping_anon_p = 1;
- }
- }
- }
-
- if (has_anonymous)
- should_dump_p = dump_mapping_p (filterflags, &v, priv,
- mapping_anon_p, mapping_file_p,
- filename);
- else
- {
- /* Older Linux kernels did not support the "Anonymous:" counter.
- If it is missing, we can't be sure - dump all the pages. */
- should_dump_p = 1;
- }
-
- /* Invoke the callback function to create the corefile segment. */
- if (should_dump_p)
- retval = func (addr, endaddr - addr, offset, inode,
- read, write, exec,
- 1, /* MODIFIED is true because we want to dump the
- mapping. */
- filename, func_data);
- if (retval != 0)
- break;
- }
-
- do_cleanups (cleanup);
- return retval;
- }
-
- return -1;
-}
-
/* A structure for passing information through
linux_find_memory_regions_full. */

diff --git a/gdb/target.c b/gdb/target.c
index 2dd3116..d25cfd4 100644
--- a/gdb/target.c
+++ b/gdb/target.c
@@ -43,6 +43,7 @@
#include "agent.h"
#include "auxv.h"
#include "target-debug.h"
+#include "target/target-utils.h"

static void target_info (char *, int);

@@ -2973,9 +2974,6 @@ target_fileio_close_cleanup (void *opaque)
target_fileio_close (fd, &target_errno);
}

-typedef int (read_alloc_pread_ftype) (int handle, gdb_byte *read_buf, int len,
- ULONGEST offset, int *target_errno);
-
/* Helper for target_fileio_read_alloc_1 to make it interruptible. */

static int
@@ -2996,57 +2994,6 @@ target_fileio_read_alloc_1_pread (int handle, gdb_byte *read_buf, int len,
more information. */

static LONGEST
-read_alloc (gdb_byte **buf_p, int handle, read_alloc_pread_ftype *pread_func,
- int padding)
-{
- size_t buf_alloc, buf_pos;
- gdb_byte *buf;
- LONGEST n;
- int target_errno;
-
- /* Start by reading up to 4K at a time. The target will throttle
- this number down if necessary. */
- buf_alloc = 4096;
- buf = xmalloc (buf_alloc);
- buf_pos = 0;
- while (1)
- {
- n = pread_func (handle, &buf[buf_pos], buf_alloc - buf_pos - padding,
- buf_pos, &target_errno);
- if (n <= 0)
- {
- if (n < 0 || (n == 0 && buf_pos == 0))
- xfree (buf);
- else
- *buf_p = buf;
- if (n < 0)
- {
- /* An error occurred. */
- return -1;
- }
- else
- {
- /* Read all there was. */
- return buf_pos;
- }
- }
-
- buf_pos += n;
-
- /* If the buffer is filling up, expand it. */
- if (buf_alloc < buf_pos * 2)
- {
- buf_alloc *= 2;
- buf = xrealloc (buf, buf_alloc);
- }
- }
-}
-
-typedef LONGEST (read_stralloc_func_ftype) (struct inferior *inf,
- const char *filename,
- gdb_byte **buf_p, int padding);
-
-static LONGEST
target_fileio_read_alloc_1 (struct inferior *inf, const char *filename,
gdb_byte **buf_p, int padding)
{
@@ -3073,41 +3020,7 @@ target_fileio_read_alloc (struct inferior *inf, const char *filename,
return target_fileio_read_alloc_1 (inf, filename, buf_p, 0);
}

-/* Helper for target_fileio_read_stralloc. */
-
-static char *
-read_stralloc (struct inferior *inf, const char *filename,
- read_stralloc_func_ftype *func)
-{
- gdb_byte *buffer;
- char *bufstr;
- LONGEST i, transferred;
-
- transferred = func (inf, filename, &buffer, 1);
- bufstr = (char *) buffer;
-
- if (transferred < 0)
- return NULL;
-
- if (transferred == 0)
- return xstrdup ("");
-
- bufstr[transferred] = 0;
-
- /* Check for embedded NUL bytes; but allow trailing NULs. */
- for (i = strlen (bufstr); i < transferred; i++)
- if (bufstr[i] != 0)
- {
- warning (_("target file %s "
- "contained unexpected null characters"),
- filename);
- break;
- }
-
- return bufstr;
-}
-
-/* See target.h. */
+/* See target/target.h. */

char *
target_fileio_read_stralloc (struct inferior *inf, const char *filename)
diff --git a/gdb/target.h b/gdb/target.h
index 32234f7..ae93a37 100644
--- a/gdb/target.h
+++ b/gdb/target.h
@@ -2033,16 +2033,6 @@ extern LONGEST target_fileio_read_alloc (struct inferior *inf,
const char *filename,
gdb_byte **buf_p);

-/* Read target file FILENAME, in the filesystem as seen by INF. If
- INF is NULL, use the filesystem seen by the debugger (GDB or, for
- remote targets, the remote stub). The result is NUL-terminated and
- returned as a string, allocated using xmalloc. If an error occurs
- or the transfer is unsupported, NULL is returned. Empty objects
- are returned as allocated but empty strings. A warning is issued
- if the result contains any embedded NUL bytes. */
-extern char *target_fileio_read_stralloc (struct inferior *inf,
- const char *filename);
-

/* Tracepoint-related operations. */

diff --git a/gdb/target/target-utils.c b/gdb/target/target-utils.c
index 4e8fae7..cdfa6e6 100644
--- a/gdb/target/target-utils.c
+++ b/gdb/target/target-utils.c
@@ -19,3 +19,82 @@

#include "common-defs.h"
#include "target/target-utils.h"
+
+LONGEST
+read_alloc (gdb_byte **buf_p, int handle, read_alloc_pread_ftype *pread_func,
+ int padding)
+{
+ size_t buf_alloc, buf_pos;
+ gdb_byte *buf;
+ LONGEST n;
+ int target_errno;
+
+ /* Start by reading up to 4K at a time. The target will throttle
+ this number down if necessary. */
+ buf_alloc = 4096;
+ buf = xmalloc (buf_alloc);
+ buf_pos = 0;
+ while (1)
+ {
+ n = pread_func (handle, &buf[buf_pos], buf_alloc - buf_pos - padding,
+ buf_pos, &target_errno);
+ if (n <= 0)
+ {
+ if (n < 0 || (n == 0 && buf_pos == 0))
+ xfree (buf);
+ else
+ *buf_p = buf;
+ if (n < 0)
+ {
+ /* An error occurred. */
+ return -1;
+ }
+ else
+ {
+ /* Read all there was. */
+ return buf_pos;
+ }
+ }
+
+ buf_pos += n;
+
+ /* If the buffer is filling up, expand it. */
+ if (buf_alloc < buf_pos * 2)
+ {
+ buf_alloc *= 2;
+ buf = xrealloc (buf, buf_alloc);
+ }
+ }
+}
+
+char *
+read_stralloc (struct inferior *inf, const char *filename,
+ read_stralloc_func_ftype *func)
+{
+ gdb_byte *buffer;
+ char *bufstr;
+ LONGEST i, transferred;
+
+ transferred = func (inf, filename, &buffer, 1);
+ bufstr = (char *) buffer;
+
+ if (transferred < 0)
+ return NULL;
+
+ if (transferred == 0)
+ return xstrdup ("");
+
+ bufstr[transferred] = 0;
+
+ /* Check for embedded NUL bytes; but allow trailing NULs. */
+ for (i = strlen (bufstr); i < transferred; i++)
+ if (bufstr[i] != 0)
+ {
+ warning (_("target file %s "
+ "contained unexpected null characters"),
+ filename);
+ break;
+ }
+
+ return bufstr;
+}
diff --git a/gdb/target/target-utils.h b/gdb/target/target-utils.h
index 443ffc3..e8bf52a 100644
--- a/gdb/target/target-utils.h
+++ b/gdb/target/target-utils.h
@@ -20,4 +20,16 @@
#ifndef TARGET_TARGET_UTILS_H
#define TARGET_TARGET_UTILS_H

+typedef int (read_alloc_pread_ftype) (int handle, gdb_byte *read_buf, int len,
+ ULONGEST offset, int *target_errno);
+extern LONGEST read_alloc (gdb_byte **buf_p, int handle,
+ read_alloc_pread_ftype *pread_func, int padding);
+
+struct inferior;
+typedef LONGEST (read_stralloc_func_ftype) (struct inferior *inf,
+ const char *filename,
+ gdb_byte **buf_p, int padding);
+extern char *read_stralloc (struct inferior *inf, const char *filename,
+ read_stralloc_func_ftype *func);
+
#endif /* TARGET_TARGET_UTILS_H */
diff --git a/gdb/target/target.h b/gdb/target/target.h
index 6ee0fee..4c85fe0 100644
--- a/gdb/target/target.h
+++ b/gdb/target/target.h
@@ -70,4 +70,15 @@ extern void target_stop_and_wait (ptid_t ptid);

extern void target_continue_no_signal (ptid_t ptid);

+/* Read target file FILENAME, in the filesystem as seen by INF. If
+ INF is NULL, use the filesystem seen by the debugger (GDB or, for
+ remote targets, the remote stub). The result is NUL-terminated and
+ returned as a string, allocated using xmalloc. If an error occurs
+ or the transfer is unsupported, NULL is returned. Empty objects
+ are returned as allocated but empty strings. A warning is issued
+ if the result contains any embedded NUL bytes. */
+struct inferior;
+extern char *target_fileio_read_stralloc (struct inferior *inf,
+ const char *filename);
+
#endif /* TARGET_COMMON_H */