git: 5dd228e81c1b - main - devel/gdb: kgdb: fixup aarch64 pcb/trapframe layout
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Date: Tue, 05 Sep 2023 18:24:18 UTC
The branch main has been updated by kevans:
URL: https://cgit.FreeBSD.org/ports/commit/?id=5dd228e81c1bcb49e0a7c5eca3927df24a607a15
commit 5dd228e81c1bcb49e0a7c5eca3927df24a607a15
Author: Kyle Evans <kevans@FreeBSD.org>
AuthorDate: 2023-09-05 18:16:59 +0000
Commit: Kyle Evans <kevans@FreeBSD.org>
CommitDate: 2023-09-05 18:23:36 +0000
devel/gdb: kgdb: fixup aarch64 pcb/trapframe layout
base 1c1f31a5e5 and 2ecbbcc7cab altered the pcb and trapframe layouts in
osreldate 1400084. This version of the patch is effectively extracted
from work done by @jhb in CheriBSD's gdb fork, then ported forward to
work with the gdb 13.x program_space_data equivalent. With
this + D39951, I can again get a solid backtrace in recent main.
While we're here, remove some special handling for kthreads not yet run,
as the stack pointer is in-fact stored in pcb_sp in cpu_copy_thread and
cpu_fork. This silences the following exception:
Python Exception <class 'gdb.error'>: Register 2 is not available
but there's not really any effect on the end result, since the thread
hasn't been scheduled yet.
Reviewed by: jhb
Approved by: jhb (maintainer)
MFH: 2023Q3
Differential Revision: https://reviews.freebsd.org/D41684
---
devel/gdb/Makefile | 2 +-
devel/gdb/files/kgdb/aarch64-fbsd-kern.c | 123 ++++++++++++++++++++++++++-----
2 files changed, 105 insertions(+), 20 deletions(-)
diff --git a/devel/gdb/Makefile b/devel/gdb/Makefile
index 378ed1e197ca..921a14b566de 100644
--- a/devel/gdb/Makefile
+++ b/devel/gdb/Makefile
@@ -1,6 +1,6 @@
PORTNAME= gdb
DISTVERSION= 13.1
-PORTREVISION= 3
+PORTREVISION= 4
CATEGORIES= devel
MASTER_SITES= GNU
diff --git a/devel/gdb/files/kgdb/aarch64-fbsd-kern.c b/devel/gdb/files/kgdb/aarch64-fbsd-kern.c
index f2d8f6511ff7..4d813c786b52 100644
--- a/devel/gdb/files/kgdb/aarch64-fbsd-kern.c
+++ b/devel/gdb/files/kgdb/aarch64-fbsd-kern.c
@@ -41,11 +41,44 @@
#include "kgdb.h"
+struct aarch64fbsd_info
+{
+ int osreldate;
+};
+
+/* Per-program-space data key. */
+static const registry<program_space>::key<aarch64fbsd_info> aarch64fbsd_pspace_data;
+
+static void
+aarch64fbsd_pspace_data_cleanup (struct program_space *pspace, void *arg)
+{
+ struct aarch64fbsd_info *info = (struct aarch64fbsd_info *)arg;
+
+ xfree (info);
+}
+
+/* Get the current aarch64_fbsd data. If none is found yet, add it
+ now. This function always returns a valid object. */
+
+static struct aarch64fbsd_info *
+get_aarch64fbsd_info (void)
+{
+ struct aarch64fbsd_info *info;
+
+ info = aarch64fbsd_pspace_data.get (current_program_space);
+ if (info != nullptr)
+ return info;
+
+ info = aarch64fbsd_pspace_data.emplace (current_program_space);
+
+ info->osreldate = parse_and_eval_long ("osreldate");
+ return info;
+}
+
static const struct regcache_map_entry aarch64_fbsd_pcbmap[] =
{
- { 30, AARCH64_X0_REGNUM, 8 }, /* x0 ... x29 */
+ { 11, AARCH64_X0_REGNUM + 19, 8 }, /* x19 ... x29 */
{ 1, AARCH64_PC_REGNUM, 8 },
- { 1, REGCACHE_MAP_SKIP, 8 },
{ 1, AARCH64_SP_REGNUM, 8 },
{ 0 }
};
@@ -56,29 +89,92 @@ static const struct regset aarch64_fbsd_pcbregset =
regcache_supply_regset, regcache_collect_regset
};
+/* In kernels prior to __FreeBSD_version 1400084, struct pcb used an
+ alternate layout. */
+
+static const struct regcache_map_entry aarch64_fbsd13_pcbmap[] =
+ {
+ { 30, AARCH64_X0_REGNUM, 8 }, /* x0 ... x29 */
+ { 1, AARCH64_PC_REGNUM, 8 },
+ { 1, REGCACHE_MAP_SKIP, 8 },
+ { 1, AARCH64_SP_REGNUM, 8 },
+ { 0 }
+ };
+
+static const struct regset aarch64_fbsd13_pcbregset =
+ {
+ aarch64_fbsd13_pcbmap,
+ regcache_supply_regset, regcache_collect_regset
+ };
+
static void
aarch64_fbsd_supply_pcb(struct regcache *regcache, CORE_ADDR pcb_addr)
{
+ const struct regset *pcbregset;
+ struct aarch64fbsd_info *info = get_aarch64fbsd_info();
gdb_byte buf[8 * 33];
+ if (info->osreldate >= 1400084)
+ pcbregset = &aarch64_fbsd_pcbregset;
+ else
+ pcbregset = &aarch64_fbsd13_pcbregset;
+
if (target_read_memory (pcb_addr, buf, sizeof buf) == 0)
- regcache_supply_regset (&aarch64_fbsd_pcbregset, regcache, -1, buf,
+ regcache_supply_regset (pcbregset, regcache, -1, buf,
sizeof (buf));
}
+static const struct regcache_map_entry aarch64_fbsd_trapframe_map[] =
+ {
+ { 1, AARCH64_SP_REGNUM, 0 },
+ { 1, AARCH64_LR_REGNUM, 0 },
+ { 1, AARCH64_PC_REGNUM, 0 },
+ { 1, AARCH64_CPSR_REGNUM, 0 },
+ { 1, REGCACHE_MAP_SKIP, 8 }, /* esr */
+ { 1, REGCACHE_MAP_SKIP, 8 }, /* far */
+ { 30, AARCH64_X0_REGNUM, 0 }, /* x0 ... x29 */
+ { 0 },
+ };
+
+/* In kernels prior to __FreeBSD_version 1400084, struct trapframe
+ used an alternate layout. */
+
+static const struct regcache_map_entry aarch64_fbsd13_trapframe_map[] =
+ {
+ { 1, AARCH64_SP_REGNUM, 0 },
+ { 1, AARCH64_LR_REGNUM, 0 },
+ { 1, AARCH64_PC_REGNUM, 0 },
+ { 1, AARCH64_CPSR_REGNUM, 4 },
+ { 1, REGCACHE_MAP_SKIP, 4 }, /* esr */
+ { 30, AARCH64_X0_REGNUM, 0 }, /* x0 ... x29 */
+ { 0 },
+ };
+
static struct trad_frame_cache *
aarch64_fbsd_trapframe_cache (frame_info_ptr this_frame, void **this_cache)
{
struct gdbarch *gdbarch = get_frame_arch (this_frame);
enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
+ struct aarch64fbsd_info *info = get_aarch64fbsd_info();
struct trad_frame_cache *cache;
CORE_ADDR func, pc, sp;
const char *name;
- int i;
+ int i, tf_size;
if (*this_cache != NULL)
return ((struct trad_frame_cache *)*this_cache);
+ const struct regcache_map_entry *trapframe_map;
+
+ if (info->osreldate >= 1400084)
+ {
+ trapframe_map = aarch64_fbsd_trapframe_map;
+ }
+ else
+ {
+ trapframe_map = aarch64_fbsd13_trapframe_map;
+ }
+
cache = trad_frame_cache_zalloc (this_frame);
*this_cache = cache;
@@ -86,23 +182,12 @@ aarch64_fbsd_trapframe_cache (frame_info_ptr this_frame, void **this_cache)
sp = get_frame_register_unsigned (this_frame, AARCH64_SP_REGNUM);
find_pc_partial_function (func, &name, NULL, NULL);
- if (strcmp(name, "fork_trampoline") == 0 && get_frame_pc (this_frame) == func)
- {
- /* fork_exit hasn't been called (kthread has never run), so SP
- hasn't been initialized yet. The stack pointer is stored in
- the X2 in the pcb. */
- sp = get_frame_register_unsigned (this_frame, AARCH64_X0_REGNUM + 2);
- }
- trad_frame_set_reg_addr (cache, AARCH64_SP_REGNUM, sp);
- trad_frame_set_reg_addr (cache, AARCH64_LR_REGNUM, sp + 8);
- trad_frame_set_reg_addr (cache, AARCH64_PC_REGNUM, sp + 16);
- trad_frame_set_reg_addr (cache, AARCH64_CPSR_REGNUM, sp + 24);
- for (i = 0; i < 30; i++)
- trad_frame_set_reg_addr (cache, AARCH64_X0_REGNUM + i, sp + 32 + i * 8);
+ tf_size = regcache_map_entry_size (trapframe_map);
+ trad_frame_set_reg_regmap (cache, trapframe_map, sp, tf_size);
/* Read $PC from trap frame. */
- pc = read_memory_unsigned_integer (sp + 16, 8, byte_order);
+ pc = read_memory_unsigned_integer (sp + 2 * 8, 8, byte_order);
if (pc == 0 && strcmp(name, "fork_trampoline") == 0)
{
@@ -112,7 +197,7 @@ aarch64_fbsd_trapframe_cache (frame_info_ptr this_frame, void **this_cache)
else
{
/* Construct the frame ID using the function start. */
- trad_frame_set_id (cache, frame_id_build (sp + 8 * 34, func));
+ trad_frame_set_id (cache, frame_id_build (sp + tf_size, func));
}
return cache;