--- Begin Message ---
- From: Jan Kratochvil <jan dot kratochvil at redhat dot com>
- Date: Wed, 3 Jun 2015 21:22:56 +0200
- Subject: [PATCH] compile: Use also inferior munmap
Currently inferior memory is allocated by inferior mmap() but it is never
deallocated; despite the injected objfile incl. its symbols is freed. This was
intentional so that one can do for example:
inferior:
char *str = "foo";
GDB:
(gdb) compile code str = "bar";
I believe later patches will be needed to introduce full control over keeping
vs. discarding the injected module as being discussed in:
compile: objfiles lifetime UI
https://sourceware.org/ml/gdb/2015-04/msg00051.html
Message-ID: <20150429135735.GA16974@host1.jankratochvil.net>
https://sourceware.org/ml/gdb/2015-05/msg00007.html
As decided by Phil it is better not to leak inferior pages as users can
workaround the issue above for example by:
(gdb) compile code str = strdup ("bar");
I have checked that in fact gdb/doc/ (written by Phil) already expects the
injected code will be unmapped so that does not need to be changed:
compile code int ff = 5; p = &ff;
In this example, @code{p} would point to @code{ff} when the
@code{compile} command is executing the source code provided to it.
However, as variables in the (example) program persist with their
assigned values, the variable @code{p} would point to an invalid
location when the command exists.
gdb/ChangeLog
2015-04-28 Jan Kratochvil <jan.kratochvil@redhat.com>
* arch-utils.c (default_infcall_munmap): New.
* arch-utils.h (default_infcall_munmap): New declaration.
* compile/compile-object-load.c (struct munmap_list, munmap_list_add)
(munmap_list_free, munmap_listp_free_cleanup): New.
(struct setup_sections_data): Add field munmap_list_headp.
(setup_sections): Call munmap_list_add.
(compile_object_load): New variable munmap_list_head, initialize
setup_sections_data.munmap_list_headp, return munmap_list_head.
* compile/compile-object-load.h (struct munmap_list): New declaration.
(struct compile_module): Add field munmap_list_head.
(munmap_list_free): New declaration.
* compile/compile-object-run.c (struct do_module_cleanup): Add field
munmap_list_head.
(do_module_cleanup): Call munmap_list_free.
(compile_object_run): Pass munmap_list_head to do_module_cleanup.
* gdbarch.c: Regenerate.
* gdbarch.h: Regenerate.
* gdbarch.sh (infcall_munmap): New.
* linux-tdep.c (linux_infcall_munmap): New.
(linux_init_abi): Install it.
gdb/testsuite/ChangeLog
2015-04-28 Jan Kratochvil <jan.kratochvil@redhat.com>
* gdb.compile/compile.exp (keep jit in memory): Rename to ...
(do not keep jit in memory): ... this.
(expect 5): Change it to ...
(expect no 5): ... this.
---
gdb/ChangeLog | 23 ++++++++++++
gdb/arch-utils.c | 6 +++
gdb/arch-utils.h | 1 +
gdb/compile/compile-object-load.c | 71 ++++++++++++++++++++++++++++++++++-
gdb/compile/compile-object-load.h | 6 +++
gdb/compile/compile-object-run.c | 6 +++
gdb/gdbarch.c | 23 ++++++++++++
gdb/gdbarch.h | 7 ++++
gdb/gdbarch.sh | 4 ++
gdb/linux-tdep.c | 30 +++++++++++++++
gdb/testsuite/ChangeLog | 7 ++++
gdb/testsuite/gdb.compile/compile.exp | 4 +-
12 files changed, 185 insertions(+), 3 deletions(-)
diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index 37d619b..3276f30 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,3 +1,26 @@
+2015-06-03 Jan Kratochvil <jan.kratochvil@redhat.com>
+
+ * arch-utils.c (default_infcall_munmap): New.
+ * arch-utils.h (default_infcall_munmap): New declaration.
+ * compile/compile-object-load.c (struct munmap_list, munmap_list_add)
+ (munmap_list_free, munmap_listp_free_cleanup): New.
+ (struct setup_sections_data): Add field munmap_list_headp.
+ (setup_sections): Call munmap_list_add.
+ (compile_object_load): New variable munmap_list_head, initialize
+ setup_sections_data.munmap_list_headp, return munmap_list_head.
+ * compile/compile-object-load.h (struct munmap_list): New declaration.
+ (struct compile_module): Add field munmap_list_head.
+ (munmap_list_free): New declaration.
+ * compile/compile-object-run.c (struct do_module_cleanup): Add field
+ munmap_list_head.
+ (do_module_cleanup): Call munmap_list_free.
+ (compile_object_run): Pass munmap_list_head to do_module_cleanup.
+ * gdbarch.c: Regenerate.
+ * gdbarch.h: Regenerate.
+ * gdbarch.sh (infcall_munmap): New.
+ * linux-tdep.c (linux_infcall_munmap): New.
+ (linux_init_abi): Install it.
+
2015-06-02 Simon Marchi <simon.marchi@ericsson.com>
PR gdb/15564
diff --git a/gdb/arch-utils.c b/gdb/arch-utils.c
index 8c3eb7c..7f07e21 100644
--- a/gdb/arch-utils.c
+++ b/gdb/arch-utils.c
@@ -864,6 +864,12 @@ default_infcall_mmap (CORE_ADDR size, unsigned prot)
error (_("This target does not support inferior memory allocation by mmap."));
}
+void
+default_infcall_munmap (CORE_ADDR addr, CORE_ADDR size)
+{
+ /* Memory reserved by inferior mmap is kept leaked. */
+}
+
/* -mcmodel=large is used so that no GOT (Global Offset Table) is needed to be
created in inferior memory by GDB (normally it is set by ld.so). */
diff --git a/gdb/arch-utils.h b/gdb/arch-utils.h
index 1be323b..9cb28e4 100644
--- a/gdb/arch-utils.h
+++ b/gdb/arch-utils.h
@@ -200,6 +200,7 @@ extern void default_skip_permanent_breakpoint (struct regcache *regcache);
#define GDB_MMAP_PROT_EXEC 0x4 /* Page can be executed. */
extern CORE_ADDR default_infcall_mmap (CORE_ADDR size, unsigned prot);
+extern void default_infcall_munmap (CORE_ADDR addr, CORE_ADDR size);
extern char *default_gcc_target_options (struct gdbarch *gdbarch);
extern const char *default_gnu_triplet_regexp (struct gdbarch *gdbarch);
diff --git a/gdb/compile/compile-object-load.c b/gdb/compile/compile-object-load.c
index 15deaaf..2b29b8b 100644
--- a/gdb/compile/compile-object-load.c
+++ b/gdb/compile/compile-object-load.c
@@ -32,6 +32,58 @@
#include "block.h"
#include "arch-utils.h"
+/* Track inferior memory reserved by inferior mmap. */
+
+struct munmap_list
+{
+ struct munmap_list *next;
+ CORE_ADDR addr, size;
+};
+
+/* Add inferior mmap memory range ADDR..ADDR+SIZE (exclusive) to list
+ HEADP. *HEADP needs to be initialized to NULL. */
+
+static void
+munmap_list_add (struct munmap_list **headp, CORE_ADDR addr, CORE_ADDR size)
+{
+ struct munmap_list *head_new = xmalloc (sizeof (*head_new));
+
+ head_new->next = *headp;
+ *headp = head_new;
+ head_new->addr = addr;
+ head_new->size = size;
+}
+
+/* Free list of inferior mmap memory ranges HEAD. HEAD is the first
+ element of the list, it can be NULL. After calling this function
+ HEAD pointer is invalid and the possible list needs to be
+ reinitialized by caller to NULL. */
+
+void
+munmap_list_free (struct munmap_list *head)
+{
+ while (head)
+ {
+ struct munmap_list *todo = head;
+
+ head = todo->next;
+ gdbarch_infcall_munmap (target_gdbarch (), todo->addr, todo->size);
+ xfree (todo);
+ }
+}
+
+/* Stub for munmap_list_free suitable for make_cleanup. Contrary to
+ munmap_list_free this function's parameter is a pointer to the first
+ list element pointer. */
+
+static void
+munmap_listp_free_cleanup (void *headp_voidp)
+{
+ struct munmap_list **headp = headp_voidp;
+
+ munmap_list_free (*headp);
+}
+
/* Helper data for setup_sections. */
struct setup_sections_data
@@ -48,6 +100,10 @@ struct setup_sections_data
/* Maximum of alignments of all sections matching LAST_PROT.
This value is always at least 1. This value is always a power of 2. */
CORE_ADDR last_max_alignment;
+
+ /* List of inferior mmap ranges where setup_sections should add its
+ next range. */
+ struct munmap_list **munmap_list_headp;
};
/* Place all ABFD sections next to each other obeying all constraints. */
@@ -97,6 +153,7 @@ setup_sections (bfd *abfd, asection *sect, void *data_voidp)
{
addr = gdbarch_infcall_mmap (target_gdbarch (), data->last_size,
data->last_prot);
+ munmap_list_add (data->munmap_list_headp, addr, data->last_size);
if (compile_debug)
fprintf_unfiltered (gdb_stdlog,
"allocated %s bytes at %s prot %u\n",
@@ -580,6 +637,7 @@ compile_object_load (const char *object_file, const char *source_file,
struct objfile *objfile;
int expect_parameters;
struct type *expect_return_type;
+ struct munmap_list *munmap_list_head = NULL;
filename = tilde_expand (object_file);
cleanups = make_cleanup (xfree, filename);
@@ -601,6 +659,8 @@ compile_object_load (const char *object_file, const char *source_file,
setup_sections_data.last_section_first = abfd->sections;
setup_sections_data.last_prot = -1;
setup_sections_data.last_max_alignment = 1;
+ setup_sections_data.munmap_list_headp = &munmap_list_head;
+ make_cleanup (munmap_listp_free_cleanup, &munmap_list_head);
bfd_map_over_sections (abfd, setup_sections, &setup_sections_data);
setup_sections (abfd, NULL, &setup_sections_data);
@@ -715,6 +775,7 @@ compile_object_load (const char *object_file, const char *source_file,
TYPE_LENGTH (regs_type),
GDB_MMAP_PROT_READ);
gdb_assert (regs_addr != 0);
+ munmap_list_add (&munmap_list_head, regs_addr, TYPE_LENGTH (regs_type));
if (compile_debug)
fprintf_unfiltered (gdb_stdlog,
"allocated %s bytes at %s for registers\n",
@@ -739,6 +800,8 @@ compile_object_load (const char *object_file, const char *source_file,
(GDB_MMAP_PROT_READ
| GDB_MMAP_PROT_WRITE));
gdb_assert (out_value_addr != 0);
+ munmap_list_add (&munmap_list_head, out_value_addr,
+ TYPE_LENGTH (out_value_type));
if (compile_debug)
fprintf_unfiltered (gdb_stdlog,
"allocated %s bytes at %s for printed value\n",
@@ -748,7 +811,6 @@ compile_object_load (const char *object_file, const char *source_file,
}
discard_cleanups (cleanups_free_objfile);
- do_cleanups (cleanups);
retval = xmalloc (sizeof (*retval));
retval->objfile = objfile;
@@ -759,5 +821,12 @@ compile_object_load (const char *object_file, const char *source_file,
retval->scope_data = scope_data;
retval->out_value_type = out_value_type;
retval->out_value_addr = out_value_addr;
+
+ /* CLEANUPS will free MUNMAP_LIST_HEAD. */
+ retval->munmap_list_head = munmap_list_head;
+ munmap_list_head = NULL;
+
+ do_cleanups (cleanups);
+
return retval;
}
diff --git a/gdb/compile/compile-object-load.h b/gdb/compile/compile-object-load.h
index 5afacda..44a7592 100644
--- a/gdb/compile/compile-object-load.h
+++ b/gdb/compile/compile-object-load.h
@@ -17,6 +17,8 @@
#ifndef GDB_COMPILE_OBJECT_LOAD_H
#define GDB_COMPILE_OBJECT_LOAD_H
+struct munmap_list;
+
struct compile_module
{
/* objfile for the compiled module. */
@@ -45,10 +47,14 @@ struct compile_module
/* If the inferior function has an out value, this is its address.
Otherwise it is zero. */
CORE_ADDR out_value_addr;
+
+ /* Track inferior memory reserved by inferior mmap. */
+ struct munmap_list *munmap_list_head;
};
extern struct compile_module *compile_object_load
(const char *object_file, const char *source_file,
enum compile_i_scope_types scope, void *scope_data);
+extern void munmap_list_free (struct munmap_list *head);
#endif /* GDB_COMPILE_OBJECT_LOAD_H */
diff --git a/gdb/compile/compile-object-run.c b/gdb/compile/compile-object-run.c
index 771a209..ce47831 100644
--- a/gdb/compile/compile-object-run.c
+++ b/gdb/compile/compile-object-run.c
@@ -47,6 +47,9 @@ struct do_module_cleanup
struct type *out_value_type;
CORE_ADDR out_value_addr;
+ /* Copy from struct compile_module. */
+ struct munmap_list *munmap_list_head;
+
/* objfile_name of our objfile. */
char objfile_name_string[1];
};
@@ -96,6 +99,8 @@ do_module_cleanup (void *arg, int registers_valid)
unlink (data->source_file);
xfree (data->source_file);
+ munmap_list_free (data->munmap_list_head);
+
/* Delete the .o file. */
unlink (data->objfile_name_string);
xfree (data);
@@ -128,6 +133,7 @@ compile_object_run (struct compile_module *module)
data->scope_data = module->scope_data;
data->out_value_type = module->out_value_type;
data->out_value_addr = module->out_value_addr;
+ data->munmap_list_head = module->munmap_list_head;
xfree (module->source_file);
xfree (module);
diff --git a/gdb/gdbarch.c b/gdb/gdbarch.c
index 821ad5e..ebff510 100644
--- a/gdb/gdbarch.c
+++ b/gdb/gdbarch.c
@@ -326,6 +326,7 @@ struct gdbarch
gdbarch_auxv_parse_ftype *auxv_parse;
gdbarch_vsyscall_range_ftype *vsyscall_range;
gdbarch_infcall_mmap_ftype *infcall_mmap;
+ gdbarch_infcall_munmap_ftype *infcall_munmap;
gdbarch_gcc_target_options_ftype *gcc_target_options;
gdbarch_gnu_triplet_regexp_ftype *gnu_triplet_regexp;
};
@@ -426,6 +427,7 @@ gdbarch_alloc (const struct gdbarch_info *info,
gdbarch->insn_is_jump = default_insn_is_jump;
gdbarch->vsyscall_range = default_vsyscall_range;
gdbarch->infcall_mmap = default_infcall_mmap;
+ gdbarch->infcall_munmap = default_infcall_munmap;
gdbarch->gcc_target_options = default_gcc_target_options;
gdbarch->gnu_triplet_regexp = default_gnu_triplet_regexp;
/* gdbarch_alloc() */
@@ -658,6 +660,7 @@ verify_gdbarch (struct gdbarch *gdbarch)
/* Skip verify of auxv_parse, has predicate. */
/* Skip verify of vsyscall_range, invalid_p == 0 */
/* Skip verify of infcall_mmap, invalid_p == 0 */
+ /* Skip verify of infcall_munmap, invalid_p == 0 */
/* Skip verify of gcc_target_options, invalid_p == 0 */
/* Skip verify of gnu_triplet_regexp, invalid_p == 0 */
buf = ui_file_xstrdup (log, &length);
@@ -1029,6 +1032,9 @@ gdbarch_dump (struct gdbarch *gdbarch, struct ui_file *file)
"gdbarch_dump: infcall_mmap = <%s>\n",
host_address_to_string (gdbarch->infcall_mmap));
fprintf_unfiltered (file,
+ "gdbarch_dump: infcall_munmap = <%s>\n",
+ host_address_to_string (gdbarch->infcall_munmap));
+ fprintf_unfiltered (file,
"gdbarch_dump: gdbarch_info_proc_p() = %d\n",
gdbarch_info_proc_p (gdbarch));
fprintf_unfiltered (file,
@@ -4673,6 +4679,23 @@ set_gdbarch_infcall_mmap (struct gdbarch *gdbarch,
gdbarch->infcall_mmap = infcall_mmap;
}
+void
+gdbarch_infcall_munmap (struct gdbarch *gdbarch, CORE_ADDR addr, CORE_ADDR size)
+{
+ gdb_assert (gdbarch != NULL);
+ gdb_assert (gdbarch->infcall_munmap != NULL);
+ if (gdbarch_debug >= 2)
+ fprintf_unfiltered (gdb_stdlog, "gdbarch_infcall_munmap called\n");
+ gdbarch->infcall_munmap (addr, size);
+}
+
+void
+set_gdbarch_infcall_munmap (struct gdbarch *gdbarch,
+ gdbarch_infcall_munmap_ftype infcall_munmap)
+{
+ gdbarch->infcall_munmap = infcall_munmap;
+}
+
char *
gdbarch_gcc_target_options (struct gdbarch *gdbarch)
{
diff --git a/gdb/gdbarch.h b/gdb/gdbarch.h
index 6f9e844..d2ccd2a 100644
--- a/gdb/gdbarch.h
+++ b/gdb/gdbarch.h
@@ -1440,6 +1440,13 @@ typedef CORE_ADDR (gdbarch_infcall_mmap_ftype) (CORE_ADDR size, unsigned prot);
extern CORE_ADDR gdbarch_infcall_mmap (struct gdbarch *gdbarch, CORE_ADDR size, unsigned prot);
extern void set_gdbarch_infcall_mmap (struct gdbarch *gdbarch, gdbarch_infcall_mmap_ftype *infcall_mmap);
+/* Deallocate SIZE bytes of memory at ADDR in inferior from gdbarch_infcall_mmap.
+ Print a warning if it is not possible. */
+
+typedef void (gdbarch_infcall_munmap_ftype) (CORE_ADDR addr, CORE_ADDR size);
+extern void gdbarch_infcall_munmap (struct gdbarch *gdbarch, CORE_ADDR addr, CORE_ADDR size);
+extern void set_gdbarch_infcall_munmap (struct gdbarch *gdbarch, gdbarch_infcall_munmap_ftype *infcall_munmap);
+
/* Return string (caller has to use xfree for it) with options for GCC
to produce code for this target, typically "-m64", "-m32" or "-m31".
These options are put before CU's DW_AT_producer compilation options so that
diff --git a/gdb/gdbarch.sh b/gdb/gdbarch.sh
index 668e3eb..a3c903e 100755
--- a/gdb/gdbarch.sh
+++ b/gdb/gdbarch.sh
@@ -1097,6 +1097,10 @@ m:int:vsyscall_range:struct mem_range *range:range::default_vsyscall_range::0
# Throw an error if it is not possible. Returned address is always valid.
f:CORE_ADDR:infcall_mmap:CORE_ADDR size, unsigned prot:size, prot::default_infcall_mmap::0
+# Deallocate SIZE bytes of memory at ADDR in inferior from gdbarch_infcall_mmap.
+# Print a warning if it is not possible.
+f:void:infcall_munmap:CORE_ADDR addr, CORE_ADDR size:addr, size::default_infcall_munmap::0
+
# Return string (caller has to use xfree for it) with options for GCC
# to produce code for this target, typically "-m64", "-m32" or "-m31".
# These options are put before CU's DW_AT_producer compilation options so that
diff --git a/gdb/linux-tdep.c b/gdb/linux-tdep.c
index df42097..8ce2f34 100644
--- a/gdb/linux-tdep.c
+++ b/gdb/linux-tdep.c
@@ -2348,6 +2348,35 @@ linux_infcall_mmap (CORE_ADDR size, unsigned prot)
return retval;
}
+/* See gdbarch.sh 'infcall_munmap'. */
+
+static void
+linux_infcall_munmap (CORE_ADDR addr, CORE_ADDR size)
+{
+ struct objfile *objf;
+ struct value *munmap_val = find_function_in_inferior ("munmap", &objf);
+ struct value *retval_val;
+ struct gdbarch *gdbarch = get_objfile_arch (objf);
+ LONGEST retval;
+ enum
+ {
+ ARG_ADDR, ARG_LENGTH, ARG_LAST
+ };
+ struct value *arg[ARG_LAST];
+
+ arg[ARG_ADDR] = value_from_pointer (builtin_type (gdbarch)->builtin_data_ptr,
+ addr);
+ /* Assuming sizeof (unsigned long) == sizeof (size_t). */
+ arg[ARG_LENGTH] = value_from_ulongest
+ (builtin_type (gdbarch)->builtin_unsigned_long, size);
+ retval_val = call_function_by_hand (munmap_val, ARG_LAST, arg);
+ retval = value_as_long (retval_val);
+ if (retval != 0)
+ warning (_("Failed inferior munmap call at %s for %s bytes, "
+ "errno is changed."),
+ hex_string (addr), pulongest (size));
+}
+
/* See linux-tdep.h. */
CORE_ADDR
@@ -2409,6 +2438,7 @@ linux_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
linux_gdb_signal_to_target);
set_gdbarch_vsyscall_range (gdbarch, linux_vsyscall_range);
set_gdbarch_infcall_mmap (gdbarch, linux_infcall_mmap);
+ set_gdbarch_infcall_munmap (gdbarch, linux_infcall_munmap);
}
/* Provide a prototype to silence -Wmissing-prototypes. */
diff --git a/gdb/testsuite/ChangeLog b/gdb/testsuite/ChangeLog
index c4f61a0..5ee74eb 100644
--- a/gdb/testsuite/ChangeLog
+++ b/gdb/testsuite/ChangeLog
@@ -1,3 +1,10 @@
+2015-06-03 Jan Kratochvil <jan.kratochvil@redhat.com>
+
+ * gdb.compile/compile.exp (keep jit in memory): Rename to ...
+ (do not keep jit in memory): ... this.
+ (expect 5): Change it to ...
+ (expect no 5): ... this.
+
2015-06-02 Simon Marchi <simon.marchi@ericsson.com>
PR gdb/15564
diff --git a/gdb/testsuite/gdb.compile/compile.exp b/gdb/testsuite/gdb.compile/compile.exp
index 07276bd..dd46a5f 100644
--- a/gdb/testsuite/gdb.compile/compile.exp
+++ b/gdb/testsuite/gdb.compile/compile.exp
@@ -131,8 +131,8 @@ gdb_test_no_output "compile code globalvar = static_local"
gdb_test "p globalvar" " = 77000" "check static_local"
gdb_test_no_output "compile code static int staticvar = 5; intptr = &staticvar" \
- "keep jit in memory"
-gdb_test "p *intptr" " = 5" "expect 5"
+ "do not keep jit in memory"
+gdb_test "p *intptr" "Cannot access memory at address 0x\[0-9a-f\]+" "expect no 5"
gdb_test "compile code func_doesnotexist ();" "warning: Could not find symbol \"func_doesnotexist\" for .*"
--
2.1.0
--- End Message ---