From: Simon Marchi <simon.marchi@efficios.com>
To: gdb-patches@sourceware.org
Cc: Simon Marchi <simon.marchi@efficios.com>
Subject: [PATCH 5/8] gdbserver/linux-x86: make is_64bit_tdesc accept thread as a parameter
Date: Thu, 17 Nov 2022 14:42:38 -0500 [thread overview]
Message-ID: <20221117194241.1776125-6-simon.marchi@efficios.com> (raw)
In-Reply-To: <20221117194241.1776125-1-simon.marchi@efficios.com>
ps_get_thread_area receives as a parameter the lwpid it must work on.
It then calls is_64bit_tdesc, which uses the current_thread as the
thread to work on. However, it is not said that both are the same.
This became a problem when working in a following patch that pmakes
find_one_thread switch to a process but to no thread (current_thread ==
nullptr). When libthread_db needed to get the thread area,
is_64bit_tdesc would try to get the regcache of a nullptr thread.
Fix that by making is_64bit_tdesc accept the thread to work on as a
parameter. Find the right thread from the context, when possible (when
we know the lwpid to work on). Otherwise, pass "current_thread", to
retain the existing behavior.
Change-Id: I44394d6be92392fa28de71982fd04517ce8a3007
---
gdbserver/linux-x86-low.cc | 27 +++++++++++++++------------
1 file changed, 15 insertions(+), 12 deletions(-)
diff --git a/gdbserver/linux-x86-low.cc b/gdbserver/linux-x86-low.cc
index d2b55f6f0d2..c98a7a461fe 100644
--- a/gdbserver/linux-x86-low.cc
+++ b/gdbserver/linux-x86-low.cc
@@ -275,9 +275,9 @@ static /*const*/ int i386_regmap[] =
per the tdesc. */
static int
-is_64bit_tdesc (void)
+is_64bit_tdesc (thread_info *thread)
{
- struct regcache *regcache = get_thread_regcache (current_thread, 0);
+ struct regcache *regcache = get_thread_regcache (thread, 0);
return register_size (regcache->tdesc, 0) == 8;
}
@@ -292,7 +292,9 @@ ps_get_thread_area (struct ps_prochandle *ph,
lwpid_t lwpid, int idx, void **base)
{
#ifdef __x86_64__
- int use_64bit = is_64bit_tdesc ();
+ lwp_info *lwp = find_lwp_pid (ptid_t (lwpid));
+ gdb_assert (lwp != nullptr);
+ int use_64bit = is_64bit_tdesc (get_lwp_thread (lwp));
if (use_64bit)
{
@@ -335,7 +337,9 @@ int
x86_target::low_get_thread_area (int lwpid, CORE_ADDR *addr)
{
#ifdef __x86_64__
- int use_64bit = is_64bit_tdesc ();
+ lwp_info *lwp = find_lwp_pid (ptid_t (lwpid));
+ gdb_assert (lwp != nullptr);
+ int use_64bit = is_64bit_tdesc (get_lwp_thread (lwp));
if (use_64bit)
{
@@ -351,7 +355,6 @@ x86_target::low_get_thread_area (int lwpid, CORE_ADDR *addr)
#endif
{
- struct lwp_info *lwp = find_lwp_pid (ptid_t (lwpid));
struct thread_info *thr = get_lwp_thread (lwp);
struct regcache *regcache = get_thread_regcache (thr, 1);
unsigned int desc[4];
@@ -379,7 +382,7 @@ bool
x86_target::low_cannot_store_register (int regno)
{
#ifdef __x86_64__
- if (is_64bit_tdesc ())
+ if (is_64bit_tdesc (current_thread))
return false;
#endif
@@ -390,7 +393,7 @@ bool
x86_target::low_cannot_fetch_register (int regno)
{
#ifdef __x86_64__
- if (is_64bit_tdesc ())
+ if (is_64bit_tdesc (current_thread))
return false;
#endif
@@ -815,7 +818,7 @@ x86_target::low_siginfo_fixup (siginfo_t *ptrace, gdb_byte *inf, int direction)
int is_elf64 = linux_pid_exe_is_elf_64_file (tid, &machine);
/* Is the inferior 32-bit? If so, then fixup the siginfo object. */
- if (!is_64bit_tdesc ())
+ if (!is_64bit_tdesc (current_thread))
return amd64_linux_siginfo_fixup_common (ptrace, inf, direction,
FIXUP_32);
/* No fixup for native x32 GDB. */
@@ -1078,7 +1081,7 @@ const regs_info *
x86_target::get_regs_info ()
{
#ifdef __x86_64__
- if (is_64bit_tdesc ())
+ if (is_64bit_tdesc (current_thread))
return &amd64_linux_regs_info;
else
#endif
@@ -1553,7 +1556,7 @@ x86_target::install_fast_tracepoint_jump_pad (CORE_ADDR tpoint,
char *err)
{
#ifdef __x86_64__
- if (is_64bit_tdesc ())
+ if (is_64bit_tdesc (current_thread))
return amd64_install_fast_tracepoint_jump_pad (tpoint, tpaddr,
collector, lockaddr,
orig_size, jump_entry,
@@ -1587,7 +1590,7 @@ x86_target::get_min_fast_tracepoint_insn_len ()
#ifdef __x86_64__
/* On x86-64, 5-byte jump instructions with a 4-byte offset are always
used for fast tracepoints. */
- if (is_64bit_tdesc ())
+ if (is_64bit_tdesc (current_thread))
return 5;
#endif
@@ -2931,7 +2934,7 @@ emit_ops *
x86_target::emit_ops ()
{
#ifdef __x86_64__
- if (is_64bit_tdesc ())
+ if (is_64bit_tdesc (current_thread))
return &amd64_emit_ops;
else
#endif
--
2.37.3
next prev parent reply other threads:[~2022-11-17 19:42 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-11-17 19:42 [PATCH 0/8] Fix some commit_resumed_state assertion failures (PR 28275) Simon Marchi
2022-11-17 19:42 ` [PATCH 1/8] gdb/testsuite: remove global declarations in gdb.threads/detach-step-over.exp Simon Marchi
2022-11-18 8:30 ` Aktemur, Tankut Baris
2022-11-18 15:07 ` Simon Marchi
2022-11-17 19:42 ` [PATCH 2/8] gdb/testsuite: refactor gdb.threads/detach-step-over.exp Simon Marchi
2022-11-17 19:42 ` [PATCH 3/8] gdb: fix assert when quitting GDB while a thread is stepping Simon Marchi
2022-11-17 19:42 ` [PATCH 4/8] gdbserver/linux: take condition out of callback in find_lwp_pid Simon Marchi
2022-11-18 11:28 ` Andrew Burgess
2022-11-18 16:09 ` Simon Marchi
2022-11-17 19:42 ` Simon Marchi [this message]
2022-11-18 11:32 ` [PATCH 5/8] gdbserver/linux-x86: make is_64bit_tdesc accept thread as a parameter Andrew Burgess
2022-11-18 16:12 ` Simon Marchi
2022-11-17 19:42 ` [PATCH 6/8] gdbserver: use current_process in ps_getpid Simon Marchi
2022-11-18 11:33 ` Andrew Burgess
2022-11-18 16:21 ` Simon Marchi
2022-11-17 19:42 ` [PATCH 7/8] gdbserver: switch to right process in find_one_thread Simon Marchi
2022-11-18 13:19 ` Andrew Burgess
2022-11-18 17:34 ` Simon Marchi
2022-11-17 19:42 ` [PATCH 8/8] gdb: disable commit resumed in target_kill Simon Marchi
2022-11-18 13:33 ` Andrew Burgess
2022-11-19 1:16 ` Simon Marchi
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