[PATCH v6 02/15] gdb: Store an x86_xsave_layout in i386_gdbarch_tdep.

John Baldwin
2023-07-14T15:56:26Z

This structure is fetched from the current target in i386_gdbarch_init
via a new "fetch_x86_xsave_layout" target method.

Approved-By: Simon Marchi <simon.marchi@efficios.com>
---
gdb/i386-tdep.c | 18 +++++++++++++++---
gdb/i386-tdep.h | 4 ++++
gdb/target-debug.h | 20 ++++++++++++++++++++
gdb/target-delegates.c | 27 +++++++++++++++++++++++++++
gdb/target.c | 6 ++++++
gdb/target.h | 7 +++++++
6 files changed, 79 insertions(+), 3 deletions(-)

diff --git a/gdb/i386-tdep.c b/gdb/i386-tdep.c
index a97e11647b9..d5423681802 100644
--- a/gdb/i386-tdep.c
+++ b/gdb/i386-tdep.c
@@ -8504,10 +8504,21 @@ i386_gdbarch_init (struct gdbarch_info info, struct gdbarch_list *arches)
int bnd0_regnum;
int num_bnd_cooked;

+ x86_xsave_layout xsave_layout = target_fetch_x86_xsave_layout ();
+
/* If there is already a candidate, use it. */
- arches = gdbarch_list_lookup_by_info (arches, &info);
- if (arches != NULL)
- return arches->gdbarch;
+ for (arches = gdbarch_list_lookup_by_info (arches, &info);
+ arches != NULL;
+ arches = gdbarch_list_lookup_by_info (arches->next, &info))
+ {
+ /* Check that the XSAVE layout of ARCHES matches the layout for
+ the current target. */
+ i386_gdbarch_tdep *other_tdep
+ = gdbarch_tdep<i386_gdbarch_tdep> (arches->gdbarch);
+
+ if (other_tdep->xsave_layout == xsave_layout)
+ return arches->gdbarch;
+ }

/* Allocate space for the new architecture. Assume i386 for now. */
gdbarch *gdbarch
@@ -8762,6 +8773,7 @@ i386_gdbarch_init (struct gdbarch_info info, struct gdbarch_list *arches)
gdbarch_free (gdbarch);
return NULL;
}
+ tdep->xsave_layout = xsave_layout;

num_bnd_cooked = (tdep->bnd0r_regnum > 0 ? I387_NUM_BND_REGS : 0);

diff --git a/gdb/i386-tdep.h b/gdb/i386-tdep.h
index bf52020ab67..34dc53db8d9 100644
--- a/gdb/i386-tdep.h
+++ b/gdb/i386-tdep.h
@@ -23,6 +23,7 @@
#include "gdbarch.h"
#include "infrun.h"
#include "expression.h"
+#include "gdbsupport/x86-xstate.h"

class frame_info_ptr;
struct gdbarch;
@@ -145,6 +146,9 @@ struct i386_gdbarch_tdep : gdbarch_tdep_base
/* Offset of XCR0 in XSAVE extended state. */
int xsave_xcr0_offset = 0;

+ /* Layout of the XSAVE area extended region. */
+ x86_xsave_layout xsave_layout;
+
/* Register names. */
const char * const *register_names = nullptr;

diff --git a/gdb/target-debug.h b/gdb/target-debug.h
index acb01d47e7c..6b8983104ea 100644
--- a/gdb/target-debug.h
+++ b/gdb/target-debug.h
@@ -236,4 +236,24 @@ target_debug_print_gdb_byte_vector_r (gdb::byte_vector &vector)
{
target_debug_print_const_gdb_byte_vector_r (vector);
}
+
+static void
+target_debug_print_x86_xsave_layout (const x86_xsave_layout &layout)
+{
+ gdb_puts ("{", gdb_stdlog);
+ gdb_printf (gdb_stdlog, " sizeof_xsave=%d", layout.sizeof_xsave);
+#define POFFS(region) \
+ if (layout.region##_offset != 0) \
+ gdb_printf (gdb_stdlog, ", %s_offset=%d", #region, \
+ layout.region##_offset)
+ POFFS(avx);
+ POFFS(bndregs);
+ POFFS(bndcfg);
+ POFFS(k);
+ POFFS(zmm_h);
+ POFFS(zmm);
+ POFFS(pkru);
+#undef POFFS
+ gdb_puts (" }", gdb_stdlog);
+}
#endif /* TARGET_DEBUG_H */
diff --git a/gdb/target-delegates.c b/gdb/target-delegates.c
index 57b66ce87b1..1d1f8c60f4e 100644
--- a/gdb/target-delegates.c
+++ b/gdb/target-delegates.c
@@ -196,6 +196,7 @@ struct dummy_target : public target_ops
bool supports_memory_tagging () override;
bool fetch_memtags (CORE_ADDR arg0, size_t arg1, gdb::byte_vector &arg2, int arg3) override;
bool store_memtags (CORE_ADDR arg0, size_t arg1, const gdb::byte_vector &arg2, int arg3) override;
+ x86_xsave_layout fetch_x86_xsave_layout () override;
};

struct debug_target : public target_ops
@@ -370,6 +371,7 @@ struct debug_target : public target_ops
bool supports_memory_tagging () override;
bool fetch_memtags (CORE_ADDR arg0, size_t arg1, gdb::byte_vector &arg2, int arg3) override;
bool store_memtags (CORE_ADDR arg0, size_t arg1, const gdb::byte_vector &arg2, int arg3) override;
+ x86_xsave_layout fetch_x86_xsave_layout () override;
};

void
@@ -4536,3 +4538,28 @@ debug_target::store_memtags (CORE_ADDR arg0, size_t arg1, const gdb::byte_vector
return result;
}

+x86_xsave_layout
+target_ops::fetch_x86_xsave_layout ()
+{
+ return this->beneath ()->fetch_x86_xsave_layout ();
+}
+
+x86_xsave_layout
+dummy_target::fetch_x86_xsave_layout ()
+{
+ return x86_xsave_layout ();
+}
+
+x86_xsave_layout
+debug_target::fetch_x86_xsave_layout ()
+{
+ x86_xsave_layout result;
+ gdb_printf (gdb_stdlog, "-> %s->fetch_x86_xsave_layout (...)\n", this->beneath ()->shortname ());
+ result = this->beneath ()->fetch_x86_xsave_layout ();
+ gdb_printf (gdb_stdlog, "<- %s->fetch_x86_xsave_layout (", this->beneath ()->shortname ());
+ gdb_puts (") = ", gdb_stdlog);
+ target_debug_print_x86_xsave_layout (result);
+ gdb_puts ("\n", gdb_stdlog);
+ return result;
+}
+
diff --git a/gdb/target.c b/gdb/target.c
index 16f43d072cd..f650e5ccb51 100644
--- a/gdb/target.c
+++ b/gdb/target.c
@@ -832,6 +832,12 @@ target_store_memtags (CORE_ADDR address, size_t len,
return current_inferior ()->top_target ()->store_memtags (address, len, tags, type);
}

+x86_xsave_layout
+target_fetch_x86_xsave_layout ()
+{
+ return current_inferior ()->top_target ()->fetch_x86_xsave_layout ();
+}
+
void
target_log_command (const char *p)
{
diff --git a/gdb/target.h b/gdb/target.h
index 6ae400e2cc2..9325b111c5b 100644
--- a/gdb/target.h
+++ b/gdb/target.h
@@ -82,6 +82,7 @@ struct inferior;
#include "disasm-flags.h"
#include "tracepoint.h"
#include "gdbsupport/fileio.h"
+#include "gdbsupport/x86-xstate.h"

#include "gdbsupport/break-common.h" /* For enum target_hw_bp_type. */

@@ -1321,6 +1322,10 @@ struct target_ops
virtual bool store_memtags (CORE_ADDR address, size_t len,
const gdb::byte_vector &tags, int type)
TARGET_DEFAULT_NORETURN (tcomplain ());
+
+ /* Return the x86 XSAVE extended state area layout. */
+ virtual x86_xsave_layout fetch_x86_xsave_layout ()
+ TARGET_DEFAULT_RETURN (x86_xsave_layout ());
};

/* Deleter for std::unique_ptr. See comments in
@@ -2301,6 +2306,8 @@ extern bool target_fetch_memtags (CORE_ADDR address, size_t len,
extern bool target_store_memtags (CORE_ADDR address, size_t len,
const gdb::byte_vector &tags, int type);

+extern x86_xsave_layout target_fetch_x86_xsave_layout ();
+
/* Command logging facility. */

extern void target_log_command (const char *p);
--
2.40.0