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gdb: make displaced stepping implementation capable of managing multiple buffers

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The displaced_step_buffer class, introduced in the previous patch,
manages access to a single displaced step buffer.  Change it into
displaced_step_buffers (note the plural), which manages access to
multiple displaced step buffers.

When preparing a displaced step for a thread, it looks for an unused
buffer.

For now, all users still pass a single displaced step buffer, so no real
behavior change is expected here.  The following patch makes a user pass
more than one buffer, so the functionality introduced by this patch is
going to be useful in the next one.

gdb/ChangeLog:

	* displaced-stepping.h (struct displaced_step_buffer): Rename
	to...
	(struct displaced_step_buffers): ... this.
	<m_addr, m_current_thread, m_copy_insn_closure>: Remove.
	<struct displaced_step_buffer>: New inner class.
	<m_buffers>: New.
	* displaced-stepping.c (displaced_step_buffer::prepare): Rename
	to...
	(displaced_step_buffers::prepare): ... this, adjust for multiple
	buffers.
	(displaced_step_buffer::finish):  Rename to...
	(displaced_step_buffers::finish): ... this, adjust for multiple
	buffers.
	(displaced_step_buffer::copy_insn_closure_by_addr): Rename to...
	(displaced_step_buffers::copy_insn_closure_by_addr): ... this,
	adjust for multiple buffers.
	(displaced_step_buffer::restore_in_ptid): Rename to...
	(displaced_step_buffers::restore_in_ptid): ... this, adjust for
	multiple buffers.
	* linux-tdep.h (linux_init_abi): Change supports_displaced_step
	for num_disp_step_buffers.
	* linux-tdep.c (struct linux_gdbarch_data)
	<num_disp_step_buffers>: New field.
	(struct linux_info) <disp_step_buf>: Rename to...
	<disp_step_bufs>: ... this, change type to
	displaced_step_buffers.
	(linux_displaced_step_prepare): Use
	linux_gdbarch_data::num_disp_step_buffers to create that number
	of buffers.
	(linux_displaced_step_finish): Adjust.
	(linux_displaced_step_copy_insn_closure_by_addr): Adjust.
	(linux_displaced_step_restore_all_in_ptid): Adjust.
	(linux_init_abi): Change supports_displaced_step parameter for
	num_disp_step_buffers, save it in linux_gdbarch_data.
	* aarch64-linux-tdep.c (aarch64_linux_init_abi): Adjust.
	* alpha-linux-tdep.c (alpha_linux_init_abi): Adjust.
	* amd64-linux-tdep.c (amd64_linux_init_abi_common): Change
	supports_displaced_step parameter for num_disp_step_buffers.
	(amd64_linux_init_abi): Adjust.
	(amd64_x32_linux_init_abi): Adjust.
	* arc-linux-tdep.c (arc_linux_init_osabi): Adjust.
	* arm-linux-tdep.c (arm_linux_init_abi): Adjust.
	* bfin-linux-tdep.c (bfin_linux_init_abi): Adjust.
	* cris-linux-tdep.c (cris_linux_init_abi): Adjust.
	* csky-linux-tdep.c (csky_linux_init_abi): Adjust.
	* frv-linux-tdep.c (frv_linux_init_abi): Adjust.
	* hppa-linux-tdep.c (hppa_linux_init_abi): Adjust.
	* i386-linux-tdep.c (i386_linux_init_abi): Adjust.
	* ia64-linux-tdep.c (ia64_linux_init_abi): Adjust.
	* m32r-linux-tdep.c (m32r_linux_init_abi): Adjust.
	* m68k-linux-tdep.c (m68k_linux_init_abi):
	* microblaze-linux-tdep.c (microblaze_linux_init_abi):
	* mips-linux-tdep.c (mips_linux_init_abi): Adjust.
	* mn10300-linux-tdep.c (am33_linux_init_osabi): Adjust.
	* nios2-linux-tdep.c (nios2_linux_init_abi): Adjust.
	* or1k-linux-tdep.c (or1k_linux_init_abi): Adjust.
	* ppc-linux-tdep.c (ppc_linux_init_abi): Adjust.
	* riscv-linux-tdep.c (riscv_linux_init_abi): Adjust.
	* rs6000-tdep.c (struct ppc_inferior_data) <disp_step_buf>:
	Change type to displaced_step_buffers.
	* s390-linux-tdep.c (s390_linux_init_abi_any): Adjust.
	* sh-linux-tdep.c (sh_linux_init_abi): Adjust.
	* sparc-linux-tdep.c (sparc32_linux_init_abi): Adjust.
	* sparc64-linux-tdep.c (sparc64_linux_init_abi): Adjust.
	* tic6x-linux-tdep.c (tic6x_uclinux_init_abi): Adjust.
	* tilegx-linux-tdep.c (tilegx_linux_init_abi): Adjust.
	* xtensa-linux-tdep.c (xtensa_linux_init_abi): Adjust.

Change-Id: Ia9c02f207da2c9e1d9188020139619122392bb70
This commit is contained in:
Simon Marchi 2020-12-04 16:43:56 -05:00
parent d965505887
commit 480af54cf6
34 changed files with 295 additions and 126 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

70
gdb/ChangeLog
View File

@ -1,3 +1,73 @@
2020-12-04 Simon Marchi <simon.marchi@efficios.com>
* displaced-stepping.h (struct displaced_step_buffer): Rename
to...
(struct displaced_step_buffers): ... this.
<m_addr, m_current_thread, m_copy_insn_closure>: Remove.
<struct displaced_step_buffer>: New inner class.
<m_buffers>: New.
* displaced-stepping.c (displaced_step_buffer::prepare): Rename
to...
(displaced_step_buffers::prepare): ... this, adjust for multiple
buffers.
(displaced_step_buffer::finish): Rename to...
(displaced_step_buffers::finish): ... this, adjust for multiple
buffers.
(displaced_step_buffer::copy_insn_closure_by_addr): Rename to...
(displaced_step_buffers::copy_insn_closure_by_addr): ... this,
adjust for multiple buffers.
(displaced_step_buffer::restore_in_ptid): Rename to...
(displaced_step_buffers::restore_in_ptid): ... this, adjust for
multiple buffers.
* linux-tdep.h (linux_init_abi): Change supports_displaced_step
for num_disp_step_buffers.
* linux-tdep.c (struct linux_gdbarch_data)
<num_disp_step_buffers>: New field.
(struct linux_info) <disp_step_buf>: Rename to...
<disp_step_bufs>: ... this, change type to
displaced_step_buffers.
(linux_displaced_step_prepare): Use
linux_gdbarch_data::num_disp_step_buffers to create that number
of buffers.
(linux_displaced_step_finish): Adjust.
(linux_displaced_step_copy_insn_closure_by_addr): Adjust.
(linux_displaced_step_restore_all_in_ptid): Adjust.
(linux_init_abi): Change supports_displaced_step parameter for
num_disp_step_buffers, save it in linux_gdbarch_data.
* aarch64-linux-tdep.c (aarch64_linux_init_abi): Adjust.
* alpha-linux-tdep.c (alpha_linux_init_abi): Adjust.
* amd64-linux-tdep.c (amd64_linux_init_abi_common): Change
supports_displaced_step parameter for num_disp_step_buffers.
(amd64_linux_init_abi): Adjust.
(amd64_x32_linux_init_abi): Adjust.
* arc-linux-tdep.c (arc_linux_init_osabi): Adjust.
* arm-linux-tdep.c (arm_linux_init_abi): Adjust.
* bfin-linux-tdep.c (bfin_linux_init_abi): Adjust.
* cris-linux-tdep.c (cris_linux_init_abi): Adjust.
* csky-linux-tdep.c (csky_linux_init_abi): Adjust.
* frv-linux-tdep.c (frv_linux_init_abi): Adjust.
* hppa-linux-tdep.c (hppa_linux_init_abi): Adjust.
* i386-linux-tdep.c (i386_linux_init_abi): Adjust.
* ia64-linux-tdep.c (ia64_linux_init_abi): Adjust.
* m32r-linux-tdep.c (m32r_linux_init_abi): Adjust.
* m68k-linux-tdep.c (m68k_linux_init_abi):
* microblaze-linux-tdep.c (microblaze_linux_init_abi):
* mips-linux-tdep.c (mips_linux_init_abi): Adjust.
* mn10300-linux-tdep.c (am33_linux_init_osabi): Adjust.
* nios2-linux-tdep.c (nios2_linux_init_abi): Adjust.
* or1k-linux-tdep.c (or1k_linux_init_abi): Adjust.
* ppc-linux-tdep.c (ppc_linux_init_abi): Adjust.
* riscv-linux-tdep.c (riscv_linux_init_abi): Adjust.
* rs6000-tdep.c (struct ppc_inferior_data) <disp_step_buf>:
Change type to displaced_step_buffers.
* s390-linux-tdep.c (s390_linux_init_abi_any): Adjust.
* sh-linux-tdep.c (sh_linux_init_abi): Adjust.
* sparc-linux-tdep.c (sparc32_linux_init_abi): Adjust.
* sparc64-linux-tdep.c (sparc64_linux_init_abi): Adjust.
* tic6x-linux-tdep.c (tic6x_uclinux_init_abi): Adjust.
* tilegx-linux-tdep.c (tilegx_linux_init_abi): Adjust.
* xtensa-linux-tdep.c (xtensa_linux_init_abi): Adjust.
2020-12-04 Simon Marchi <simon.marchi@efficios.com>
* linux-tdep.c (init_linux_gdbarch_data): Change parameter to

2
gdb/aarch64-linux-tdep.c
View File

@ -1445,7 +1445,7 @@ aarch64_linux_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
tdep->lowest_pc = 0x8000;
linux_init_abi (info, gdbarch, true);
linux_init_abi (info, gdbarch, 1);
set_solib_svr4_fetch_link_map_offsets (gdbarch,
svr4_lp64_fetch_link_map_offsets);

2
gdb/alpha-linux-tdep.c
View File

@ -356,7 +356,7 @@ alpha_linux_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
{
struct gdbarch_tdep *tdep;
linux_init_abi (info, gdbarch, false);
linux_init_abi (info, gdbarch, 0);
/* Hook into the DWARF CFI frame unwinder. */
alpha_dwarf2_init_abi (info, gdbarch);

8
gdb/amd64-linux-tdep.c
View File

@ -1796,11 +1796,11 @@ amd64_dtrace_parse_probe_argument (struct gdbarch *gdbarch,
static void
amd64_linux_init_abi_common(struct gdbarch_info info, struct gdbarch *gdbarch,
bool supports_displaced_step)
int num_disp_step_buffers)
{
struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
linux_init_abi (info, gdbarch, supports_displaced_step);
linux_init_abi (info, gdbarch, num_disp_step_buffers);
tdep->sigtramp_p = amd64_linux_sigtramp_p;
tdep->sigcontext_addr = amd64_linux_sigcontext_addr;
@ -1880,7 +1880,7 @@ amd64_linux_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
if (!valid_p)
return;
amd64_linux_init_abi_common (info, gdbarch, true);
amd64_linux_init_abi_common (info, gdbarch, 1);
/* Initialize the amd64_linux_record_tdep. */
/* These values are the size of the type that will be used in a system
@ -2095,7 +2095,7 @@ amd64_x32_linux_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
if (!valid_p)
return;
amd64_linux_init_abi_common (info, gdbarch, false);
amd64_linux_init_abi_common (info, gdbarch, 0);
/* Initialize the amd64_x32_linux_record_tdep. */
/* These values are the size of the type that will be used in a system

2
gdb/arc-linux-tdep.c
View File

@ -439,7 +439,7 @@ arc_linux_init_osabi (struct gdbarch_info info, struct gdbarch *gdbarch)
*/
tdep->jb_pc = 15;
linux_init_abi (info, gdbarch, false);
linux_init_abi (info, gdbarch, 0);
/* Set up target dependent GDB architecture entries. */
set_gdbarch_cannot_fetch_register (gdbarch, arc_linux_cannot_fetch_register);

2
gdb/arm-linux-tdep.c
View File

@ -1721,7 +1721,7 @@ arm_linux_init_abi (struct gdbarch_info info,
NULL };
struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
linux_init_abi (info, gdbarch, true);
linux_init_abi (info, gdbarch, 1);
tdep->lowest_pc = 0x8000;
if (info.byte_order_for_code == BFD_ENDIAN_BIG)

2
gdb/bfin-linux-tdep.c
View File

@ -150,7 +150,7 @@ bfin_linux_get_syscall_number (struct gdbarch *gdbarch,
static void
bfin_linux_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
{
linux_init_abi (info, gdbarch, false);
linux_init_abi (info, gdbarch, 0);
/* Set the sigtramp frame sniffer. */
tramp_frame_prepend_unwinder (gdbarch, &bfin_linux_sigframe);

2
gdb/cris-linux-tdep.c
View File

@ -35,7 +35,7 @@ cris_linux_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
{
struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
linux_init_abi (info, gdbarch, false);
linux_init_abi (info, gdbarch, 0);
if (tdep->cris_version == 32)
/* Threaded debugging is only supported on CRISv32 for now. */

2
gdb/csky-linux-tdep.c
View File

@ -233,7 +233,7 @@ csky_linux_rt_sigreturn_tramp_frame = {
static void
csky_linux_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
{
linux_init_abi (info, gdbarch, false);
linux_init_abi (info, gdbarch, 0);
/* Shared library handling. */
set_gdbarch_skip_trampoline_code (gdbarch, find_solib_trampoline_target);

152
gdb/displaced-stepping.c
View File

@ -44,24 +44,43 @@ show_debug_displaced (struct ui_file *file, int from_tty,
}
displaced_step_prepare_status
displaced_step_buffer::prepare (thread_info *thread, CORE_ADDR &displaced_pc)
displaced_step_buffers::prepare (thread_info *thread, CORE_ADDR &displaced_pc)
{
gdb_assert (!thread->displaced_step_state.in_progress ());
/* Is a thread currently using the buffer? */
if (m_current_thread != nullptr)
{
/* If so, it better not be this thread. */
gdb_assert (thread != m_current_thread);
return DISPLACED_STEP_PREPARE_STATUS_UNAVAILABLE;
}
/* Sanity check: the thread should not be using a buffer at this point. */
for (displaced_step_buffer &buf : m_buffers)
gdb_assert (buf.current_thread != thread);
regcache *regcache = get_thread_regcache (thread);
const address_space *aspace = regcache->aspace ();
gdbarch *arch = regcache->arch ();
ULONGEST len = gdbarch_max_insn_length (arch);
if (breakpoint_in_range_p (aspace, m_addr, len))
/* Search for an unused buffer. */
displaced_step_buffer *buffer = nullptr;
displaced_step_prepare_status fail_status
= DISPLACED_STEP_PREPARE_STATUS_CANT;
for (displaced_step_buffer &candidate : m_buffers)
{
bool bp_in_range = breakpoint_in_range_p (aspace, candidate.addr, len);
bool is_free = candidate.current_thread == nullptr;
if (!bp_in_range)
{
if (is_free)
{
buffer = &candidate;
break;
}
else
{
/* This buffer would be suitable, but it's used right now. */
fail_status = DISPLACED_STEP_PREPARE_STATUS_UNAVAILABLE;
}
}
else
{
/* There's a breakpoint set in the scratch pad location range
(which is usually around the entry point). We'd either
@ -72,34 +91,45 @@ displaced_step_buffer::prepare (thread_info *thread, CORE_ADDR &displaced_pc)
in the scratch pad range (after initial startup) anyway, but
the former is unacceptable. Simply punt and fallback to
stepping over this breakpoint in-line. */
displaced_debug_printf ("breakpoint set in scratch pad. "
"Stepping over breakpoint in-line instead.");
return DISPLACED_STEP_PREPARE_STATUS_CANT;
displaced_debug_printf ("breakpoint set in displaced stepping "
"buffer at %s, can't use.",
paddress (arch, candidate.addr));
}
}
m_original_pc = regcache_read_pc (regcache);
displaced_pc = m_addr;
if (buffer == nullptr)
return fail_status;
displaced_debug_printf ("selected buffer at %s",
paddress (arch, buffer->addr));
/* Save the original PC of the thread. */
buffer->original_pc = regcache_read_pc (regcache);
/* Return displaced step buffer address to caller. */
displaced_pc = buffer->addr;
/* Save the original contents of the displaced stepping buffer. */
m_saved_copy.resize (len);
buffer->saved_copy.resize (len);
int status = target_read_memory (m_addr, m_saved_copy.data (), len);
int status = target_read_memory (buffer->addr,
buffer->saved_copy.data (), len);
if (status != 0)
throw_error (MEMORY_ERROR,
_("Error accessing memory address %s (%s) for "
"displaced-stepping scratch space."),
paddress (arch, m_addr), safe_strerror (status));
paddress (arch, buffer->addr), safe_strerror (status));
displaced_debug_printf ("saved %s: %s",
paddress (arch, m_addr),
paddress (arch, buffer->addr),
displaced_step_dump_bytes
(m_saved_copy.data (), len).c_str ());
(buffer->saved_copy.data (), len).c_str ());
/* Save this in a local variable first, so it's released if code below
throws. */
displaced_step_copy_insn_closure_up copy_insn_closure
= gdbarch_displaced_step_copy_insn (arch, m_original_pc, m_addr, regcache);
= gdbarch_displaced_step_copy_insn (arch, buffer->original_pc,
buffer->addr, regcache);
if (copy_insn_closure == nullptr)
{
@ -110,16 +140,25 @@ displaced_step_buffer::prepare (thread_info *thread, CORE_ADDR &displaced_pc)
}
/* Resume execution at the copy. */
regcache_write_pc (regcache, m_addr);
regcache_write_pc (regcache, buffer->addr);
/* This marks the buffer as being in use. */
m_current_thread = thread;
buffer->current_thread = thread;
/* Save this, now that we know everything went fine. */
m_copy_insn_closure = std::move (copy_insn_closure);
buffer->copy_insn_closure = std::move (copy_insn_closure);
/* Tell infrun not to try preparing a displaced step again for this inferior. */
/* Tell infrun not to try preparing a displaced step again for this inferior if
all buffers are taken. */
thread->inf->displaced_step_state.unavailable = true;
for (const displaced_step_buffer &buf : m_buffers)
{
if (buf.current_thread == nullptr)
{
thread->inf->displaced_step_state.unavailable = false;
break;
}
}
return DISPLACED_STEP_PREPARE_STATUS_OK;
}
@ -152,21 +191,34 @@ displaced_step_instruction_executed_successfully (gdbarch *arch,
}
displaced_step_finish_status
displaced_step_buffer::finish (gdbarch *arch, thread_info *thread,
displaced_step_buffers::finish (gdbarch *arch, thread_info *thread,
gdb_signal sig)
{
gdb_assert (thread->displaced_step_state.in_progress ());
gdb_assert (thread == m_current_thread);
/* Find the buffer this thread was using. */
displaced_step_buffer *buffer = nullptr;
for (displaced_step_buffer &candidate : m_buffers)
{
if (candidate.current_thread == thread)
{
buffer = &candidate;
break;
}
}
gdb_assert (buffer != nullptr);
/* Move this to a local variable so it's released in case something goes
wrong. */
displaced_step_copy_insn_closure_up copy_insn_closure
= std::move (m_copy_insn_closure);
= std::move (buffer->copy_insn_closure);
gdb_assert (copy_insn_closure != nullptr);
/* Reset M_CURRENT_THREAD immediately to mark the buffer as available, in case
something goes wrong below. */
m_current_thread = nullptr;
/* Reset BUFFER->CURRENT_THREAD immediately to mark the buffer as available,
in case something goes wrong below. */
buffer->current_thread = nullptr;
/* Now that a buffer gets freed, tell infrun it can ask us to prepare a displaced
step again for this inferior. Do that here in case something goes wrong
@ -175,12 +227,13 @@ displaced_step_buffer::finish (gdbarch *arch, thread_info *thread,
ULONGEST len = gdbarch_max_insn_length (arch);
write_memory_ptid (thread->ptid, m_addr,
m_saved_copy.data (), len);
/* Restore memory of the buffer. */
write_memory_ptid (thread->ptid, buffer->addr,
buffer->saved_copy.data (), len);
displaced_debug_printf ("restored %s %s",
target_pid_to_str (thread->ptid).c_str (),
paddress (arch, m_addr));
paddress (arch, buffer->addr));
regcache *rc = get_thread_regcache (thread);
@ -189,8 +242,9 @@ displaced_step_buffer::finish (gdbarch *arch, thread_info *thread,
if (instruction_executed_successfully)
{
gdbarch_displaced_step_fixup (arch, copy_insn_closure.get (), m_original_pc,
m_addr, rc);
gdbarch_displaced_step_fixup (arch, copy_insn_closure.get (),
buffer->original_pc,
buffer->addr, rc);
return DISPLACED_STEP_FINISH_STATUS_OK;
}
else
@ -198,35 +252,41 @@ displaced_step_buffer::finish (gdbarch *arch, thread_info *thread,
/* Since the instruction didn't complete, all we can do is relocate the
PC. */
CORE_ADDR pc = regcache_read_pc (rc);
pc = m_original_pc + (pc - m_addr);
pc = buffer->original_pc + (pc - buffer->addr);
regcache_write_pc (rc, pc);
return DISPLACED_STEP_FINISH_STATUS_NOT_EXECUTED;
}
}
const displaced_step_copy_insn_closure *
displaced_step_buffer::copy_insn_closure_by_addr (CORE_ADDR addr)
displaced_step_buffers::copy_insn_closure_by_addr (CORE_ADDR addr)
{
if (addr == m_addr)
return m_copy_insn_closure.get ();
else
for (const displaced_step_buffer &buffer : m_buffers)
{
if (addr == buffer.addr)
return buffer.copy_insn_closure.get ();
}
return nullptr;
}
void
displaced_step_buffer::restore_in_ptid (ptid_t ptid)
displaced_step_buffers::restore_in_ptid (ptid_t ptid)
{
if (m_current_thread != nullptr)
for (const displaced_step_buffer &buffer : m_buffers)
{
regcache *regcache = get_thread_regcache (m_current_thread);
if (buffer.current_thread == nullptr)
continue;
regcache *regcache = get_thread_regcache (buffer.current_thread);
gdbarch *arch = regcache->arch ();
ULONGEST len = gdbarch_max_insn_length (arch);
write_memory_ptid (ptid, m_addr, m_saved_copy.data (), len);
write_memory_ptid (ptid, buffer.addr, buffer.saved_copy.data (), len);
displaced_debug_printf ("restored in ptid %s %s",
target_pid_to_str (ptid).c_str (),
paddress (arch, m_addr));
paddress (arch, buffer.addr));
}
}

51
gdb/displaced-stepping.h
View File

@ -20,6 +20,7 @@
#ifndef DISPLACED_STEPPING_H
#define DISPLACED_STEPPING_H
#include "gdbsupport/array-view.h"
#include "gdbsupport/byte-vector.h"
struct gdbarch;
@ -154,13 +155,19 @@ private:
gdbarch *m_original_gdbarch = nullptr;
};
/* Manage access to a single displaced stepping buffer. */
/* Control access to multiple displaced stepping buffers at fixed addresses. */
struct displaced_step_buffer
struct displaced_step_buffers
{
explicit displaced_step_buffer (CORE_ADDR buffer_addr)
: m_addr (buffer_addr)
{}
explicit displaced_step_buffers (gdb::array_view<CORE_ADDR> buffer_addrs)
{
gdb_assert (buffer_addrs.size () > 0);
m_buffers.reserve (buffer_addrs.size ());
for (CORE_ADDR buffer_addr : buffer_addrs)
m_buffers.emplace_back (buffer_addr);
}
displaced_step_prepare_status prepare (thread_info *thread,
CORE_ADDR &displaced_pc);
@ -174,21 +181,35 @@ struct displaced_step_buffer
void restore_in_ptid (ptid_t ptid);
private:
/* Original PC of the instruction being displaced-stepped in this buffer. */
CORE_ADDR m_original_pc = 0;
/* State of a single buffer. */
struct displaced_step_buffer
{
explicit displaced_step_buffer (CORE_ADDR addr)
: addr (addr)
{}
/* Address of the buffer. */
const CORE_ADDR m_addr;
const CORE_ADDR addr;
/* If set, the thread currently using the buffer. */
thread_info *m_current_thread = nullptr;
/* The original PC of the instruction currently being stepped. */
CORE_ADDR original_pc = 0;
/* Saved contents of copy area. */
gdb::byte_vector m_saved_copy;
/* If set, the thread currently using the buffer. If unset, the buffer is not
used. */
thread_info *current_thread = nullptr;
/* The closure provided gdbarch_displaced_step_copy_insn, to be used
for post-step cleanup. */
displaced_step_copy_insn_closure_up m_copy_insn_closure;
/* Saved copy of the bytes in the displaced buffer, to be restored once the
buffer is no longer used. */
gdb::byte_vector saved_copy;
/* Closure obtained from gdbarch_displaced_step_copy_insn, to be passed to
gdbarch_displaced_step_fixup_insn. */
displaced_step_copy_insn_closure_up copy_insn_closure;
};
std::vector<displaced_step_buffer> m_buffers;
};
#endif /* DISPLACED_STEPPING_H */

2
gdb/frv-linux-tdep.c
View File

@ -456,7 +456,7 @@ frv_linux_iterate_over_regset_sections (struct gdbarch *gdbarch,
static void
frv_linux_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
{
linux_init_abi (info, gdbarch, false);
linux_init_abi (info, gdbarch, 0);
/* Set the sigtramp frame sniffer. */
frame_unwind_append_unwinder (gdbarch, &frv_linux_sigtramp_frame_unwind);

2
gdb/hppa-linux-tdep.c
View File

@ -489,7 +489,7 @@ hppa_linux_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
{
struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
linux_init_abi (info, gdbarch, false);
linux_init_abi (info, gdbarch, 0);
/* GNU/Linux is always ELF. */
tdep->is_elf = 1;

2
gdb/i386-linux-tdep.c
View File

@ -832,7 +832,7 @@ i386_linux_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
gdb_assert (tdesc_data);
linux_init_abi (info, gdbarch, true);
linux_init_abi (info, gdbarch, 1);
/* GNU/Linux uses ELF. */
i386_elf_init_abi (info, gdbarch);

2
gdb/ia64-linux-tdep.c
View File

@ -223,7 +223,7 @@ ia64_linux_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
static const char *const stap_register_indirection_suffixes[] = { "]",
NULL };
linux_init_abi (info, gdbarch, false);
linux_init_abi (info, gdbarch, 0);
/* Set the method of obtaining the sigcontext addresses at which
registers are saved. */

48
gdb/linux-tdep.c
View File

@ -168,6 +168,7 @@ static struct gdbarch_data *linux_gdbarch_data_handle;
struct linux_gdbarch_data
{
struct type *siginfo_type;
int num_disp_step_buffers;
};
static void *
@ -200,8 +201,8 @@ struct linux_info
if we tried looking it up but failed. */
int vsyscall_range_p = 0;
/* Inferior's displaced step buffer. */
gdb::optional<displaced_step_buffer> disp_step_buf;
/* Inferior's displaced step buffers. */
gdb::optional<displaced_step_buffers> disp_step_bufs;
};
/* Per-inferior data key. */
@ -2540,15 +2541,25 @@ linux_displaced_step_prepare (gdbarch *arch, thread_info *thread,
{
linux_info *per_inferior = get_linux_inferior_data (thread->inf);
if (!per_inferior->disp_step_buf.has_value ())
if (!per_inferior->disp_step_bufs.has_value ())
{
/* Figure out the location of the buffers. They are contiguous, starting
at DISP_STEP_BUF_ADDR. They are all of size BUF_LEN. */
CORE_ADDR disp_step_buf_addr
= linux_displaced_step_location (thread->inf->gdbarch);
int buf_len = gdbarch_max_insn_length (arch);
per_inferior->disp_step_buf.emplace (disp_step_buf_addr);
linux_gdbarch_data *gdbarch_data = get_linux_gdbarch_data (arch);
gdb_assert (gdbarch_data->num_disp_step_buffers > 0);
std::vector<CORE_ADDR> buffers;
for (int i = 0; i < gdbarch_data->num_disp_step_buffers; i++)
buffers.push_back (disp_step_buf_addr + i * buf_len);
per_inferior->disp_step_bufs.emplace (buffers);
}
return per_inferior->disp_step_buf->prepare (thread, displaced_pc);
return per_inferior->disp_step_bufs->prepare (thread, displaced_pc);
}
/* See linux-tdep.h. */
@ -2558,9 +2569,9 @@ linux_displaced_step_finish (gdbarch *arch, thread_info *thread, gdb_signal sig)
{
linux_info *per_inferior = get_linux_inferior_data (thread->inf);
gdb_assert (per_inferior->disp_step_buf.has_value ());
gdb_assert (per_inferior->disp_step_bufs.has_value ());
return per_inferior->disp_step_buf->finish (arch, thread, sig);
return per_inferior->disp_step_bufs->finish (arch, thread, sig);
}
/* See linux-tdep.h. */
@ -2571,10 +2582,10 @@ linux_displaced_step_copy_insn_closure_by_addr (inferior *inf, CORE_ADDR addr)
linux_info *per_inferior = linux_inferior_data.get (inf);
if (per_inferior == nullptr
|| !per_inferior->disp_step_buf.has_value ())
|| !per_inferior->disp_step_bufs.has_value ())
return nullptr;
return per_inferior->disp_step_buf->copy_insn_closure_by_addr (addr);
return per_inferior->disp_step_bufs->copy_insn_closure_by_addr (addr);
}
/* See linux-tdep.h. */
@ -2585,10 +2596,10 @@ linux_displaced_step_restore_all_in_ptid (inferior *parent_inf, ptid_t ptid)
linux_info *per_inferior = linux_inferior_data.get (parent_inf);
if (per_inferior == nullptr
|| !per_inferior->disp_step_buf.has_value ())
|| !per_inferior->disp_step_bufs.has_value ())
return;
per_inferior->disp_step_buf->restore_in_ptid (ptid);
per_inferior->disp_step_bufs->restore_in_ptid (ptid);
}
/* See linux-tdep.h. */
@ -2636,15 +2647,22 @@ show_dump_excluded_mappings (struct ui_file *file, int from_tty,
}
/* To be called from the various GDB_OSABI_LINUX handlers for the
various GNU/Linux architectures and machine types. */
various GNU/Linux architectures and machine types.
NUM_DISP_STEP_BUFFERS is the number of displaced step buffers to use. If 0,
displaced stepping is not supported. */
void
linux_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch,
bool supports_displaced_step)
int num_disp_step_buffers)
{
if (supports_displaced_step)
if (num_disp_step_buffers > 0)
{
set_gdbarch_displaced_step_prepare (gdbarch, linux_displaced_step_prepare);
linux_gdbarch_data *gdbarch_data = get_linux_gdbarch_data (gdbarch);
gdbarch_data->num_disp_step_buffers = num_disp_step_buffers;
set_gdbarch_displaced_step_prepare (gdbarch,
linux_displaced_step_prepare);
set_gdbarch_displaced_step_finish (gdbarch, linux_displaced_step_finish);
set_gdbarch_displaced_step_copy_insn_closure_by_addr
(gdbarch, linux_displaced_step_copy_insn_closure_by_addr);

2
gdb/linux-tdep.h
View File

@ -82,7 +82,7 @@ extern void linux_displaced_step_restore_all_in_ptid (inferior *parent_inf,
ptid_t ptid);
extern void linux_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch,
bool supports_displaced_step);
int num_disp_step_buffers);
extern int linux_is_uclinux (void);

2
gdb/m32r-linux-tdep.c
View File

@ -449,7 +449,7 @@ static void
m32r_linux_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
{
linux_init_abi (info, gdbarch, false);
linux_init_abi (info, gdbarch, 0);
/* Since EVB register is not available for native debug, we reduce
the number of registers. */

2
gdb/m68k-linux-tdep.c
View File

@ -385,7 +385,7 @@ m68k_linux_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
{
struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
linux_init_abi (info, gdbarch, false);
linux_init_abi (info, gdbarch, 0);
tdep->jb_pc = M68K_LINUX_JB_PC;
tdep->jb_elt_size = M68K_LINUX_JB_ELEMENT_SIZE;

2
gdb/microblaze-linux-tdep.c
View File

@ -117,7 +117,7 @@ static void
microblaze_linux_init_abi (struct gdbarch_info info,
struct gdbarch *gdbarch)
{
linux_init_abi (info, gdbarch, false);
linux_init_abi (info, gdbarch, 0);
set_gdbarch_memory_remove_breakpoint (gdbarch,
microblaze_linux_memory_remove_breakpoint);

2
gdb/mips-linux-tdep.c
View File

@ -1531,7 +1531,7 @@ mips_linux_init_abi (struct gdbarch_info info,
enum mips_abi abi = mips_abi (gdbarch);
struct tdesc_arch_data *tdesc_data = info.tdesc_data;
linux_init_abi (info, gdbarch, false);
linux_init_abi (info, gdbarch, 0);
/* Get the syscall number from the arch's register. */
set_gdbarch_get_syscall_number (gdbarch, mips_linux_get_syscall_number);

2
gdb/mn10300-linux-tdep.c
View File

@ -704,7 +704,7 @@ am33_linux_sigframe_cache_init (const struct tramp_frame *self,
static void
am33_linux_init_osabi (struct gdbarch_info info, struct gdbarch *gdbarch)
{
linux_init_abi (info, gdbarch, false);
linux_init_abi (info, gdbarch, 0);
set_gdbarch_iterate_over_regset_sections
(gdbarch, am33_iterate_over_regset_sections);

2
gdb/nios2-linux-tdep.c
View File

@ -219,7 +219,7 @@ nios2_linux_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
{
struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
linux_init_abi (info, gdbarch, false);
linux_init_abi (info, gdbarch, 0);
/* Shared library handling. */
set_gdbarch_skip_trampoline_code (gdbarch, find_solib_trampoline_target);

2
gdb/or1k-linux-tdep.c
View File

@ -140,7 +140,7 @@ or1k_linux_sigframe_init (const struct tramp_frame *self,
static void
or1k_linux_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
{
linux_init_abi (info, gdbarch, false);
linux_init_abi (info, gdbarch, 0);
set_solib_svr4_fetch_link_map_offsets (gdbarch,
svr4_ilp32_fetch_link_map_offsets);

2
gdb/ppc-linux-tdep.c
View File

@ -1993,7 +1993,7 @@ ppc_linux_init_abi (struct gdbarch_info info,
static const char *const stap_register_indirection_suffixes[] = { ")",
NULL };
linux_init_abi (info, gdbarch, false);
linux_init_abi (info, gdbarch, 0);
/* PPC GNU/Linux uses either 64-bit or 128-bit long doubles; where
128-bit, they can be either IBM long double or IEEE quad long double.

2
gdb/riscv-linux-tdep.c
View File

@ -159,7 +159,7 @@ riscv_linux_sigframe_init (const struct tramp_frame *self,
static void
riscv_linux_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
{
linux_init_abi (info, gdbarch, false);
linux_init_abi (info, gdbarch, 0);
set_gdbarch_software_single_step (gdbarch, riscv_software_single_step);

2
gdb/rs6000-tdep.c
View File

@ -160,7 +160,7 @@ struct ppc_inferior_data
/* This is an optional in case we add more fields to ppc_inferior_data, we
don't want it instantiated as soon as we get the ppc_inferior_data for an
inferior. */
gdb::optional<displaced_step_buffer> disp_step_buf;
gdb::optional<displaced_step_buffers> disp_step_buf;
};
static inferior_key<ppc_inferior_data> ppc_inferior_data_key;

2
gdb/s390-linux-tdep.c
View File

@ -1119,7 +1119,7 @@ s390_linux_init_abi_any (struct gdbarch_info info, struct gdbarch *gdbarch)
tdep->s390_syscall_record = s390_linux_syscall_record;
linux_init_abi (info, gdbarch, false);
linux_init_abi (info, gdbarch, 0);
/* Register handling. */
set_gdbarch_core_read_description (gdbarch, s390_core_read_description);

2
gdb/sh-linux-tdep.c
View File

@ -184,7 +184,7 @@ static struct tramp_frame sh_linux_rt_sigreturn_tramp_frame = {
static void
sh_linux_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
{
linux_init_abi (info, gdbarch, false);
linux_init_abi (info, gdbarch, 0);
/* GNU/Linux uses SVR4-style shared libraries. */
set_gdbarch_skip_trampoline_code (gdbarch, find_solib_trampoline_target);

2
gdb/sparc-linux-tdep.c
View File

@ -422,7 +422,7 @@ sparc32_linux_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
{
struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
linux_init_abi (info, gdbarch, false);
linux_init_abi (info, gdbarch, 0);
tdep->gregset = &sparc32_linux_gregset;
tdep->sizeof_gregset = 152;

2
gdb/sparc64-linux-tdep.c
View File

@ -365,7 +365,7 @@ sparc64_linux_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
{
struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
linux_init_abi (info, gdbarch, false);
linux_init_abi (info, gdbarch, 0);
tdep->gregset = &sparc64_linux_gregset;
tdep->sizeof_gregset = 288;

2
gdb/tic6x-linux-tdep.c
View File

@ -167,7 +167,7 @@ tic6x_uclinux_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
{
struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
linux_init_abi (info, gdbarch, false);
linux_init_abi (info, gdbarch, 0);
/* Shared library handling. */
set_solib_ops (gdbarch, &dsbt_so_ops);

2
gdb/tilegx-linux-tdep.c
View File

@ -111,7 +111,7 @@ tilegx_linux_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
{
int arch_size = gdbarch_addr_bit (gdbarch);
linux_init_abi (info, gdbarch, false);
linux_init_abi (info, gdbarch, 0);
tramp_frame_prepend_unwinder (gdbarch, &tilegx_linux_rt_sigframe);

2
gdb/xtensa-linux-tdep.c
View File

@ -110,7 +110,7 @@ xtensa_linux_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
set_gdbarch_num_pseudo_regs (gdbarch, tdep->num_pseudo_regs);
}
linux_init_abi (info, gdbarch, false);
linux_init_abi (info, gdbarch, 0);
set_solib_svr4_fetch_link_map_offsets
(gdbarch, svr4_ilp32_fetch_link_map_offsets);