[PATCH v6 02/25] New gdbarch memory tagging hooks
Luis Machado
luis.machado@linaro.org
Mon Mar 22 13:20:56 GMT 2021
Updates on v6:
- NULL -> nullptr.
- Adjusted function comments.
- Fixed identation.
- Change memtag_type to enum class.
- Changed default_memtag_to_string to error out.
Updates on v4:
- Updated return type of gdbarch_set_memtags to bool.
- Renamed gdbarch_memtag_mismatch_p to gdbarch_memtag_matches_p.
- Renamed gdbarch_granule_size to gdbarch_memtag_granule_size.
--
We need some new gdbarch hooks to help us manipulate memory tags without having
to have GDB call the target methods directly.
This patch adds the following hooks:
gdbarch_memtag_to_string
--
Returns a printable string corresponding to the tag.
gdbarch_tagged_address_p
--
Checks if a particular address is protected with memory tagging.
gdbarch_memtag_matches_p
--
Checks if the logical tag of a pointer and the allocation tag from the address
the pointer points to matches.
gdbarch_set_memtags:
--
Sets either the allocation tag or the logical tag for a particular value.
gdbarch_get_memtag:
--
Gets either the allocation tag or the logical tag for a particular value.
gdbarch_memtag_granule_size
--
Sets the memory tag granule size, which represents the number of bytes a
particular allocation tag covers. For example, this is 16 bytes for
AArch64's MTE.
I've used struct value as opposed to straight CORE_ADDR so other architectures
can use the infrastructure without having to rely on a particular type for
addresses/pointers. Some architecture may use pointers of 16 bytes that don't
fit in a CORE_ADDR, for example.
gdb/ChangeLog:
YYYY-MM-DD Luis Machado <luis.machado@linaro.org>
* arch-utils.c (default_memtag_to_string, default_tagged_address_p)
(default_memtag_matches_p, default_set_memtags)
(default_get_memtag): New functions.
* arch-utils.h (default_memtag_to_string, default_tagged_address_p)
(default_memtag_matches_p, default_set_memtags)
(default_get_memtag): New prototypes.
* gdbarch.c: Regenerate.
* gdbarch.h: Regenerate.
* gdbarch.sh (memtag_to_string, tagged_address_p, memtag_matches_p)
(set_memtags, get_memtag, memtag_granule_size): New gdbarch hooks.
(enum memtag_type): New enum.
---
gdb/arch-utils.c | 49 +++++++++++++++++
gdb/arch-utils.h | 22 ++++++++
gdb/gdbarch.c | 139 ++++++++++++++++++++++++++++++++++++++++++++++-
gdb/gdbarch.h | 54 ++++++++++++++++++
gdb/gdbarch.sh | 37 +++++++++++++
5 files changed, 300 insertions(+), 1 deletion(-)
diff --git a/gdb/arch-utils.c b/gdb/arch-utils.c
index b5547424e48..0017e706ef1 100644
--- a/gdb/arch-utils.c
+++ b/gdb/arch-utils.c
@@ -77,6 +77,55 @@ legacy_register_sim_regno (struct gdbarch *gdbarch, int regnum)
return LEGACY_SIM_REGNO_IGNORE;
}
+
+/* See arch-utils.h */
+
+std::string
+default_memtag_to_string (struct gdbarch *gdbarch, struct value *tag)
+{
+ error (_("This architecture has no method to convert a memory tag to"
+ " a string."));
+}
+
+/* See arch-utils.h */
+
+bool
+default_tagged_address_p (struct gdbarch *gdbarch, struct value *address)
+{
+ /* By default, assume the address is untagged. */
+ return false;
+}
+
+/* See arch-utils.h */
+
+bool
+default_memtag_matches_p (struct gdbarch *gdbarch, struct value *address)
+{
+ /* By default, assume the tags match. */
+ return true;
+}
+
+/* See arch-utils.h */
+
+bool
+default_set_memtags (struct gdbarch *gdbarch, struct value *address,
+ size_t length, const gdb::byte_vector &tags,
+ memtag_type tag_type)
+{
+ /* By default, return true (successful); */
+ return true;
+}
+
+/* See arch-utils.h */
+
+struct value *
+default_get_memtag (struct gdbarch *gdbarch, struct value *address,
+ memtag_type tag_type)
+{
+ /* By default, return no tag. */
+ return nullptr;
+}
+
CORE_ADDR
generic_skip_trampoline_code (struct frame_info *frame, CORE_ADDR pc)
{
diff --git a/gdb/arch-utils.h b/gdb/arch-utils.h
index a7e53ea5ae8..a5b40ad8ff1 100644
--- a/gdb/arch-utils.h
+++ b/gdb/arch-utils.h
@@ -132,6 +132,28 @@ extern const struct floatformat **
default_floatformat_for_type (struct gdbarch *gdbarch,
const char *name, int len);
+/* Default implementation of gdbarch_memtag_to_string. */
+extern std::string default_memtag_to_string (struct gdbarch *gdbarch,
+ struct value *tag);
+
+/* Default implementation of gdbarch_tagged_address_p. */
+bool default_tagged_address_p (struct gdbarch *gdbarch, struct value *address);
+
+/* Default implementation of gdbarch_memtag_matches_p. */
+extern bool default_memtag_matches_p (struct gdbarch *gdbarch,
+ struct value *address);
+
+/* Default implementation of gdbarch_set_memtags. */
+bool default_set_memtags (struct gdbarch *gdbarch,
+ struct value *address, size_t length,
+ const gdb::byte_vector &tags,
+ memtag_type tag_type);
+
+/* Default implementation of gdbarch_get_memtag. */
+struct value *default_get_memtag (struct gdbarch *gdbarch,
+ struct value *address,
+ memtag_type tag_type);
+
extern CORE_ADDR generic_skip_trampoline_code (struct frame_info *frame,
CORE_ADDR pc);
diff --git a/gdb/gdbarch.c b/gdb/gdbarch.c
index 8fa3cbaea3d..23509ba0a98 100644
--- a/gdb/gdbarch.c
+++ b/gdb/gdbarch.c
@@ -253,6 +253,12 @@ struct gdbarch
gdbarch_convert_from_func_ptr_addr_ftype *convert_from_func_ptr_addr;
gdbarch_addr_bits_remove_ftype *addr_bits_remove;
int significant_addr_bit;
+ gdbarch_memtag_to_string_ftype *memtag_to_string;
+ gdbarch_tagged_address_p_ftype *tagged_address_p;
+ gdbarch_memtag_matches_p_ftype *memtag_matches_p;
+ gdbarch_set_memtags_ftype *set_memtags;
+ gdbarch_get_memtag_ftype *get_memtag;
+ CORE_ADDR memtag_granule_size;
gdbarch_software_single_step_ftype *software_single_step;
gdbarch_single_step_through_delay_ftype *single_step_through_delay;
gdbarch_print_insn_ftype *print_insn;
@@ -433,6 +439,11 @@ gdbarch_alloc (const struct gdbarch_info *info,
gdbarch->stabs_argument_has_addr = default_stabs_argument_has_addr;
gdbarch->convert_from_func_ptr_addr = convert_from_func_ptr_addr_identity;
gdbarch->addr_bits_remove = core_addr_identity;
+ gdbarch->memtag_to_string = default_memtag_to_string;
+ gdbarch->tagged_address_p = default_tagged_address_p;
+ gdbarch->memtag_matches_p = default_memtag_matches_p;
+ gdbarch->set_memtags = default_set_memtags;
+ gdbarch->get_memtag = default_get_memtag;
gdbarch->print_insn = default_print_insn;
gdbarch->skip_trampoline_code = generic_skip_trampoline_code;
gdbarch->skip_solib_resolver = generic_skip_solib_resolver;
@@ -626,6 +637,12 @@ verify_gdbarch (struct gdbarch *gdbarch)
/* Skip verify of convert_from_func_ptr_addr, invalid_p == 0 */
/* Skip verify of addr_bits_remove, invalid_p == 0 */
/* Skip verify of significant_addr_bit, invalid_p == 0 */
+ /* Skip verify of memtag_to_string, invalid_p == 0 */
+ /* Skip verify of tagged_address_p, invalid_p == 0 */
+ /* Skip verify of memtag_matches_p, invalid_p == 0 */
+ /* Skip verify of set_memtags, invalid_p == 0 */
+ /* Skip verify of get_memtag, invalid_p == 0 */
+ /* Skip verify of memtag_granule_size, invalid_p == 0 */
/* Skip verify of software_single_step, has predicate. */
/* Skip verify of single_step_through_delay, has predicate. */
/* Skip verify of print_insn, invalid_p == 0 */
@@ -1088,6 +1105,9 @@ gdbarch_dump (struct gdbarch *gdbarch, struct ui_file *file)
fprintf_unfiltered (file,
"gdbarch_dump: get_longjmp_target = <%s>\n",
host_address_to_string (gdbarch->get_longjmp_target));
+ fprintf_unfiltered (file,
+ "gdbarch_dump: get_memtag = <%s>\n",
+ host_address_to_string (gdbarch->get_memtag));
fprintf_unfiltered (file,
"gdbarch_dump: get_pc_address_flags = <%s>\n",
host_address_to_string (gdbarch->get_pc_address_flags));
@@ -1217,6 +1237,15 @@ gdbarch_dump (struct gdbarch *gdbarch, struct ui_file *file)
fprintf_unfiltered (file,
"gdbarch_dump: memory_remove_breakpoint = <%s>\n",
host_address_to_string (gdbarch->memory_remove_breakpoint));
+ fprintf_unfiltered (file,
+ "gdbarch_dump: memtag_granule_size = %s\n",
+ core_addr_to_string_nz (gdbarch->memtag_granule_size));
+ fprintf_unfiltered (file,
+ "gdbarch_dump: memtag_matches_p = <%s>\n",
+ host_address_to_string (gdbarch->memtag_matches_p));
+ fprintf_unfiltered (file,
+ "gdbarch_dump: memtag_to_string = <%s>\n",
+ host_address_to_string (gdbarch->memtag_to_string));
fprintf_unfiltered (file,
"gdbarch_dump: num_pseudo_regs = %s\n",
plongest (gdbarch->num_pseudo_regs));
@@ -1370,6 +1399,9 @@ gdbarch_dump (struct gdbarch *gdbarch, struct ui_file *file)
fprintf_unfiltered (file,
"gdbarch_dump: sdb_reg_to_regnum = <%s>\n",
host_address_to_string (gdbarch->sdb_reg_to_regnum));
+ fprintf_unfiltered (file,
+ "gdbarch_dump: set_memtags = <%s>\n",
+ host_address_to_string (gdbarch->set_memtags));
fprintf_unfiltered (file,
"gdbarch_dump: short_bit = %s\n",
plongest (gdbarch->short_bit));
@@ -1478,6 +1510,9 @@ gdbarch_dump (struct gdbarch *gdbarch, struct ui_file *file)
fprintf_unfiltered (file,
"gdbarch_dump: syscalls_info = %s\n",
host_address_to_string (gdbarch->syscalls_info));
+ fprintf_unfiltered (file,
+ "gdbarch_dump: tagged_address_p = <%s>\n",
+ host_address_to_string (gdbarch->tagged_address_p));
fprintf_unfiltered (file,
"gdbarch_dump: target_desc = %s\n",
host_address_to_string (gdbarch->target_desc));
@@ -3283,6 +3318,108 @@ set_gdbarch_significant_addr_bit (struct gdbarch *gdbarch,
gdbarch->significant_addr_bit = significant_addr_bit;
}
+std::string
+gdbarch_memtag_to_string (struct gdbarch *gdbarch, struct value *tag)
+{
+ gdb_assert (gdbarch != NULL);
+ gdb_assert (gdbarch->memtag_to_string != NULL);
+ if (gdbarch_debug >= 2)
+ fprintf_unfiltered (gdb_stdlog, "gdbarch_memtag_to_string called\n");
+ return gdbarch->memtag_to_string (gdbarch, tag);
+}
+
+void
+set_gdbarch_memtag_to_string (struct gdbarch *gdbarch,
+ gdbarch_memtag_to_string_ftype memtag_to_string)
+{
+ gdbarch->memtag_to_string = memtag_to_string;
+}
+
+bool
+gdbarch_tagged_address_p (struct gdbarch *gdbarch, struct value *address)
+{
+ gdb_assert (gdbarch != NULL);
+ gdb_assert (gdbarch->tagged_address_p != NULL);
+ if (gdbarch_debug >= 2)
+ fprintf_unfiltered (gdb_stdlog, "gdbarch_tagged_address_p called\n");
+ return gdbarch->tagged_address_p (gdbarch, address);
+}
+
+void
+set_gdbarch_tagged_address_p (struct gdbarch *gdbarch,
+ gdbarch_tagged_address_p_ftype tagged_address_p)
+{
+ gdbarch->tagged_address_p = tagged_address_p;
+}
+
+bool
+gdbarch_memtag_matches_p (struct gdbarch *gdbarch, struct value *address)
+{
+ gdb_assert (gdbarch != NULL);
+ gdb_assert (gdbarch->memtag_matches_p != NULL);
+ if (gdbarch_debug >= 2)
+ fprintf_unfiltered (gdb_stdlog, "gdbarch_memtag_matches_p called\n");
+ return gdbarch->memtag_matches_p (gdbarch, address);
+}
+
+void
+set_gdbarch_memtag_matches_p (struct gdbarch *gdbarch,
+ gdbarch_memtag_matches_p_ftype memtag_matches_p)
+{
+ gdbarch->memtag_matches_p = memtag_matches_p;
+}
+
+bool
+gdbarch_set_memtags (struct gdbarch *gdbarch, struct value *address, size_t length, const gdb::byte_vector &tags, memtag_type tag_type)
+{
+ gdb_assert (gdbarch != NULL);
+ gdb_assert (gdbarch->set_memtags != NULL);
+ if (gdbarch_debug >= 2)
+ fprintf_unfiltered (gdb_stdlog, "gdbarch_set_memtags called\n");
+ return gdbarch->set_memtags (gdbarch, address, length, tags, tag_type);
+}
+
+void
+set_gdbarch_set_memtags (struct gdbarch *gdbarch,
+ gdbarch_set_memtags_ftype set_memtags)
+{
+ gdbarch->set_memtags = set_memtags;
+}
+
+struct value *
+gdbarch_get_memtag (struct gdbarch *gdbarch, struct value *address, memtag_type tag_type)
+{
+ gdb_assert (gdbarch != NULL);
+ gdb_assert (gdbarch->get_memtag != NULL);
+ if (gdbarch_debug >= 2)
+ fprintf_unfiltered (gdb_stdlog, "gdbarch_get_memtag called\n");
+ return gdbarch->get_memtag (gdbarch, address, tag_type);
+}
+
+void
+set_gdbarch_get_memtag (struct gdbarch *gdbarch,
+ gdbarch_get_memtag_ftype get_memtag)
+{
+ gdbarch->get_memtag = get_memtag;
+}
+
+CORE_ADDR
+gdbarch_memtag_granule_size (struct gdbarch *gdbarch)
+{
+ gdb_assert (gdbarch != NULL);
+ /* Skip verify of memtag_granule_size, invalid_p == 0 */
+ if (gdbarch_debug >= 2)
+ fprintf_unfiltered (gdb_stdlog, "gdbarch_memtag_granule_size called\n");
+ return gdbarch->memtag_granule_size;
+}
+
+void
+set_gdbarch_memtag_granule_size (struct gdbarch *gdbarch,
+ CORE_ADDR memtag_granule_size)
+{
+ gdbarch->memtag_granule_size = memtag_granule_size;
+}
+
bool
gdbarch_software_single_step_p (struct gdbarch *gdbarch)
{
@@ -5314,7 +5451,7 @@ struct gdbarch_data_registry
struct gdbarch_data_registration *registrations;
};
-static struct gdbarch_data_registry gdbarch_data_registry =
+struct gdbarch_data_registry gdbarch_data_registry =
{
0, NULL,
};
diff --git a/gdb/gdbarch.h b/gdb/gdbarch.h
index 342c29c5980..7157e5596fd 100644
--- a/gdb/gdbarch.h
+++ b/gdb/gdbarch.h
@@ -117,6 +117,18 @@ enum function_call_return_method
return_method_struct,
};
+enum class memtag_type
+{
+ /* Logical tag, the tag that is stored in unused bits of a pointer to a
+ virtual address. */
+ logical = 0,
+
+ /* Allocation tag, the tag that is associated with every granule of memory in
+ the physical address space. Allocation tags are used to validate memory
+ accesses via pointers containing logical tags. */
+ allocation,
+};
+
/* The following are pre-initialized by GDBARCH. */
@@ -712,6 +724,48 @@ extern void set_gdbarch_addr_bits_remove (struct gdbarch *gdbarch, gdbarch_addr_
extern int gdbarch_significant_addr_bit (struct gdbarch *gdbarch);
extern void set_gdbarch_significant_addr_bit (struct gdbarch *gdbarch, int significant_addr_bit);
+/* Return a string representation of the memory tag TAG. */
+
+typedef std::string (gdbarch_memtag_to_string_ftype) (struct gdbarch *gdbarch, struct value *tag);
+extern std::string gdbarch_memtag_to_string (struct gdbarch *gdbarch, struct value *tag);
+extern void set_gdbarch_memtag_to_string (struct gdbarch *gdbarch, gdbarch_memtag_to_string_ftype *memtag_to_string);
+
+/* Return true if ADDRESS contains a tag and false otherwise. */
+
+typedef bool (gdbarch_tagged_address_p_ftype) (struct gdbarch *gdbarch, struct value *address);
+extern bool gdbarch_tagged_address_p (struct gdbarch *gdbarch, struct value *address);
+extern void set_gdbarch_tagged_address_p (struct gdbarch *gdbarch, gdbarch_tagged_address_p_ftype *tagged_address_p);
+
+/* Return true if the tag from ADDRESS matches the memory tag for that
+ particular address. Return false otherwise. */
+
+typedef bool (gdbarch_memtag_matches_p_ftype) (struct gdbarch *gdbarch, struct value *address);
+extern bool gdbarch_memtag_matches_p (struct gdbarch *gdbarch, struct value *address);
+extern void set_gdbarch_memtag_matches_p (struct gdbarch *gdbarch, gdbarch_memtag_matches_p_ftype *memtag_matches_p);
+
+/* Set the tags of type TAG_TYPE, for the memory address range
+ [ADDRESS, ADDRESS + LENGTH) to TAGS.
+ Return true if successful and false otherwise. */
+
+typedef bool (gdbarch_set_memtags_ftype) (struct gdbarch *gdbarch, struct value *address, size_t length, const gdb::byte_vector &tags, memtag_type tag_type);
+extern bool gdbarch_set_memtags (struct gdbarch *gdbarch, struct value *address, size_t length, const gdb::byte_vector &tags, memtag_type tag_type);
+extern void set_gdbarch_set_memtags (struct gdbarch *gdbarch, gdbarch_set_memtags_ftype *set_memtags);
+
+/* Return the tag of type TAG_TYPE associated with the memory address ADDRESS,
+ assuming ADDRESS is tagged. */
+
+typedef struct value * (gdbarch_get_memtag_ftype) (struct gdbarch *gdbarch, struct value *address, memtag_type tag_type);
+extern struct value * gdbarch_get_memtag (struct gdbarch *gdbarch, struct value *address, memtag_type tag_type);
+extern void set_gdbarch_get_memtag (struct gdbarch *gdbarch, gdbarch_get_memtag_ftype *get_memtag);
+
+/* memtag_granule_size is the size of the allocation tag granule, for
+ architectures that support memory tagging.
+ This is 0 for architectures that do not support memory tagging.
+ For a non-zero value, this represents the number of bytes of memory per tag. */
+
+extern CORE_ADDR gdbarch_memtag_granule_size (struct gdbarch *gdbarch);
+extern void set_gdbarch_memtag_granule_size (struct gdbarch *gdbarch, CORE_ADDR memtag_granule_size);
+
/* FIXME/cagney/2001-01-18: This should be split in two. A target method that
indicates if the target needs software single step. An ISA method to
implement it.
diff --git a/gdb/gdbarch.sh b/gdb/gdbarch.sh
index 84b645e9915..6c361307428 100755
--- a/gdb/gdbarch.sh
+++ b/gdb/gdbarch.sh
@@ -605,6 +605,31 @@ m;CORE_ADDR;addr_bits_remove;CORE_ADDR addr;addr;;core_addr_identity;;0
# additional data associated with the address.
v;int;significant_addr_bit;;;;;;0
+# Return a string representation of the memory tag TAG.
+m;std::string;memtag_to_string;struct value *tag;tag;;default_memtag_to_string;;0
+
+# Return true if ADDRESS contains a tag and false otherwise.
+m;bool;tagged_address_p;struct value *address;address;;default_tagged_address_p;;0
+
+# Return true if the tag from ADDRESS matches the memory tag for that
+# particular address. Return false otherwise.
+m;bool;memtag_matches_p;struct value *address;address;;default_memtag_matches_p;;0
+
+# Set the tags of type TAG_TYPE, for the memory address range
+# [ADDRESS, ADDRESS + LENGTH) to TAGS.
+# Return true if successful and false otherwise.
+m;bool;set_memtags;struct value *address, size_t length, const gdb::byte_vector \&tags, memtag_type tag_type;address, length, tags, tag_type;;default_set_memtags;;0
+
+# Return the tag of type TAG_TYPE associated with the memory address ADDRESS,
+# assuming ADDRESS is tagged.
+m;struct value *;get_memtag;struct value *address, memtag_type tag_type;address, tag_type;;default_get_memtag;;0
+
+# memtag_granule_size is the size of the allocation tag granule, for
+# architectures that support memory tagging.
+# This is 0 for architectures that do not support memory tagging.
+# For a non-zero value, this represents the number of bytes of memory per tag.
+v;CORE_ADDR;memtag_granule_size;;;;;;0
+
# FIXME/cagney/2001-01-18: This should be split in two. A target method that
# indicates if the target needs software single step. An ISA method to
# implement it.
@@ -1362,6 +1387,18 @@ enum function_call_return_method
return_method_struct,
};
+enum class memtag_type
+{
+ /* Logical tag, the tag that is stored in unused bits of a pointer to a
+ virtual address. */
+ logical = 0,
+
+ /* Allocation tag, the tag that is associated with every granule of memory in
+ the physical address space. Allocation tags are used to validate memory
+ accesses via pointers containing logical tags. */
+ allocation,
+};
+
EOF
# function typedef's
--
2.25.1
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