gdb/gdb-arm-remove-tpidruro-register-from-non-freebsd-ta.patch

220 lines
7.9 KiB
Diff

From 7973eaf11e33ddd405830b9bd29495991db5901d Mon Sep 17 00:00:00 2001
From: Thiago Jung Bauermann <thiago.bauermann@linaro.org>
Date: Mon, 26 Feb 2024 19:11:45 -0300
Subject: [PATCH 2/7] gdb/arm: Remove tpidruro register from non-FreeBSD target
descriptions
Commit 92d48a1e4eac ("Add an arm-tls feature which includes the tpidruro
register from CP15.") introduced the org.gnu.gdb.arm.tls feature, which
adds the tpidruro register, and unconditionally enabled it in
aarch32_create_target_description.
In Linux, the tpidruro register isn't available via ptrace in the 32-bit
kernel but it is available for an aarch32 program running under an arm64
kernel via the ptrace compat interface. This isn't currently implemented
however, which causes GDB on arm-linux with 64-bit kernel to list the
register but show it as unavailable, as reported by Tom de Vries:
$ gdb -q -batch a.out -ex start -ex 'p $tpidruro'
Temporary breakpoint 1 at 0x512
Temporary breakpoint 1, 0xaaaaa512 in main ()
$1 = <unavailable>
Simon Marchi then clarified:
> The only time we should be seeing some "unavailable" registers or memory
> is in the context of tracepoints, for things that are not collected.
> Seeing an unavailable register here is a sign that something is not
> right.
Therefore, disable the TLS feature in aarch32 target descriptions for Linux
and NetBSD targets (the latter also doesn't seem to support accessing
tpidruro either, based on a quick look at arm-netbsd-nat.c).
This patch fixes the following tests:
Running gdb.base/inline-frame-cycle-unwind.exp ...
FAIL: gdb.base/inline-frame-cycle-unwind.exp: cycle at level 3: backtrace when the unwind is broken at frame 3
FAIL: gdb.base/inline-frame-cycle-unwind.exp: cycle at level 5: backtrace when the unwind is broken at frame 5
FAIL: gdb.base/inline-frame-cycle-unwind.exp: cycle at level 1: backtrace when the unwind is broken at frame 1
Tested with Ubuntu 22.04.3 on armv8l-linux-gnueabihf in native,
native-gdbserver and native-extended-gdbserver targets with no regressions.
PR tdep/31418
Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=31418
Approved-By: John Baldwin <jhb@FreeBSD.org>
---
gdb/aarch32-tdep.c | 15 ++++++++++-----
gdb/aarch32-tdep.h | 2 +-
gdb/aarch64-linux-nat.c | 2 +-
gdb/arch/aarch32.c | 5 +++--
gdb/arch/aarch32.h | 2 +-
gdb/arm-fbsd-tdep.c | 2 +-
gdb/arm-linux-nat.c | 2 +-
gdb/arm-linux-tdep.c | 2 +-
gdb/arm-netbsd-nat.c | 2 +-
gdbserver/linux-aarch32-tdesc.cc | 2 +-
10 files changed, 21 insertions(+), 15 deletions(-)
diff --git a/gdb/aarch32-tdep.c b/gdb/aarch32-tdep.c
index bfa88a96522..395328936e4 100644
--- a/gdb/aarch32-tdep.c
+++ b/gdb/aarch32-tdep.c
@@ -22,15 +22,20 @@
#include "gdbsupport/common-regcache.h"
#include "arch/aarch32.h"
-static struct target_desc *tdesc_aarch32;
+static struct target_desc *tdesc_aarch32_list[2];
/* See aarch32-tdep.h. */
const target_desc *
-aarch32_read_description ()
+aarch32_read_description (bool tls)
{
- if (tdesc_aarch32 == nullptr)
- tdesc_aarch32 = aarch32_create_target_description ();
+ struct target_desc *tdesc = tdesc_aarch32_list[tls];
- return tdesc_aarch32;
+ if (tdesc == nullptr)
+ {
+ tdesc = aarch32_create_target_description (tls);
+ tdesc_aarch32_list[tls] = tdesc;
+ }
+
+ return tdesc;
}
diff --git a/gdb/aarch32-tdep.h b/gdb/aarch32-tdep.h
index bee4d4e9fc0..efc93351298 100644
--- a/gdb/aarch32-tdep.h
+++ b/gdb/aarch32-tdep.h
@@ -22,6 +22,6 @@ struct target_desc;
/* Get the AArch32 target description. */
-const target_desc *aarch32_read_description ();
+const target_desc *aarch32_read_description (bool tls);
#endif /* aarch32-tdep.h. */
diff --git a/gdb/aarch64-linux-nat.c b/gdb/aarch64-linux-nat.c
index 768748a20db..c680d6de0c9 100644
--- a/gdb/aarch64-linux-nat.c
+++ b/gdb/aarch64-linux-nat.c
@@ -887,7 +887,7 @@ aarch64_linux_nat_target::read_description ()
ret = ptrace (PTRACE_GETREGSET, tid, NT_ARM_VFP, &iovec);
if (ret == 0)
- return aarch32_read_description ();
+ return aarch32_read_description (false);
CORE_ADDR hwcap = linux_get_hwcap ();
CORE_ADDR hwcap2 = linux_get_hwcap2 ();
diff --git a/gdb/arch/aarch32.c b/gdb/arch/aarch32.c
index 5be2cc0156e..b7510ee41e9 100644
--- a/gdb/arch/aarch32.c
+++ b/gdb/arch/aarch32.c
@@ -25,7 +25,7 @@
/* See aarch32.h. */
target_desc *
-aarch32_create_target_description ()
+aarch32_create_target_description (bool tls)
{
target_desc_up tdesc = allocate_target_description ();
@@ -39,7 +39,8 @@ aarch32_create_target_description ()
/* Create a vfpv3 feature, then a blank NEON feature. */
regnum = create_feature_arm_arm_vfpv3 (tdesc.get (), regnum);
tdesc_create_feature (tdesc.get (), "org.gnu.gdb.arm.neon");
- regnum = create_feature_arm_arm_tls (tdesc.get (), regnum);
+ if (tls)
+ regnum = create_feature_arm_arm_tls (tdesc.get (), regnum);
return tdesc.release ();
}
diff --git a/gdb/arch/aarch32.h b/gdb/arch/aarch32.h
index 6b24ae94335..e06e260e370 100644
--- a/gdb/arch/aarch32.h
+++ b/gdb/arch/aarch32.h
@@ -22,6 +22,6 @@
/* Create the AArch32 target description. */
-target_desc *aarch32_create_target_description ();
+target_desc *aarch32_create_target_description (bool tls);
#endif /* aarch32.h. */
diff --git a/gdb/arm-fbsd-tdep.c b/gdb/arm-fbsd-tdep.c
index b46fa91d0a0..a4cea77f388 100644
--- a/gdb/arm-fbsd-tdep.c
+++ b/gdb/arm-fbsd-tdep.c
@@ -228,7 +228,7 @@ arm_fbsd_read_description_auxv (const gdb::optional<gdb::byte_vector> &auxv,
if (arm_hwcap & HWCAP_VFP)
{
if (arm_hwcap & HWCAP_NEON)
- return aarch32_read_description ();
+ return aarch32_read_description (tls);
else if ((arm_hwcap & (HWCAP_VFPv3 | HWCAP_VFPD32))
== (HWCAP_VFPv3 | HWCAP_VFPD32))
return arm_read_description (ARM_FP_TYPE_VFPV3, tls);
diff --git a/gdb/arm-linux-nat.c b/gdb/arm-linux-nat.c
index 70c6bc684fa..07af23d3881 100644
--- a/gdb/arm-linux-nat.c
+++ b/gdb/arm-linux-nat.c
@@ -568,7 +568,7 @@ arm_linux_nat_target::read_description ()
/* NEON implies VFPv3-D32 or no-VFP unit. Say that we only support
Neon with VFPv3-D32. */
if (arm_hwcap & HWCAP_NEON)
- return aarch32_read_description ();
+ return aarch32_read_description (false);
else if ((arm_hwcap & (HWCAP_VFPv3 | HWCAP_VFPv3D16)) == HWCAP_VFPv3)
return arm_read_description (ARM_FP_TYPE_VFPV3, false);
diff --git a/gdb/arm-linux-tdep.c b/gdb/arm-linux-tdep.c
index dfa816990ff..33748731cfd 100644
--- a/gdb/arm-linux-tdep.c
+++ b/gdb/arm-linux-tdep.c
@@ -740,7 +740,7 @@ arm_linux_core_read_description (struct gdbarch *gdbarch,
/* NEON implies VFPv3-D32 or no-VFP unit. Say that we only support
Neon with VFPv3-D32. */
if (arm_hwcap & HWCAP_NEON)
- return aarch32_read_description ();
+ return aarch32_read_description (false);
else if ((arm_hwcap & (HWCAP_VFPv3 | HWCAP_VFPv3D16)) == HWCAP_VFPv3)
return arm_read_description (ARM_FP_TYPE_VFPV3, false);
diff --git a/gdb/arm-netbsd-nat.c b/gdb/arm-netbsd-nat.c
index d83714a46c3..018964b010d 100644
--- a/gdb/arm-netbsd-nat.c
+++ b/gdb/arm-netbsd-nat.c
@@ -350,7 +350,7 @@ arm_netbsd_nat_target::read_description ()
len = sizeof(flag);
if (sysctlbyname("machdep.neon_present", &flag, &len, NULL, 0) == 0 && flag)
- return aarch32_read_description ();
+ return aarch32_read_description (false);
return arm_read_description (ARM_FP_TYPE_VFPV3, false);
}
diff --git a/gdbserver/linux-aarch32-tdesc.cc b/gdbserver/linux-aarch32-tdesc.cc
index e1380fa2a40..443f91e3585 100644
--- a/gdbserver/linux-aarch32-tdesc.cc
+++ b/gdbserver/linux-aarch32-tdesc.cc
@@ -32,7 +32,7 @@ aarch32_linux_read_description ()
{
if (tdesc_aarch32 == nullptr)
{
- tdesc_aarch32 = aarch32_create_target_description ();
+ tdesc_aarch32 = aarch32_create_target_description (false);
static const char *expedite_regs[] = { "r11", "sp", "pc", 0 };
init_target_desc (tdesc_aarch32, expedite_regs);
--
2.35.3