* [PATCH v2 1/3] gdb, gdbserver, zpoint: report z_point support
2023-11-14 9:20 [PATCH v2 0/3] Check for zpoint support when handling watchpoints Mohamed Bouhaouel
@ 2023-11-14 9:20 ` Mohamed Bouhaouel
2023-11-14 12:50 ` Eli Zaretskii
2023-11-14 9:20 ` [PATCH v2 2/3] gdb, breakpoint: add a breakpoint type converter Mohamed Bouhaouel
2023-11-14 9:20 ` [PATCH v2 3/3] gdb, zpoint: check for target hardware breakpoint support Mohamed Bouhaouel
2 siblings, 1 reply; 5+ messages in thread
From: Mohamed Bouhaouel @ 2023-11-14 9:20 UTC (permalink / raw)
To: gdb-patches; +Cc: blarsen, mohamed.bouhaouel
Make gdbserver report which types of breakpoints and watchpoints
are supported when exchanging features. This is done by replying with
Z<type>+ (Supported) or Z<type>- (unsupported)
---
gdb/NEWS | 4 ++++
gdb/doc/gdb.texinfo | 32 ++++++++++++++++++++++++++++++++
gdb/remote.c | 16 ++++++++++++++++
gdbserver/mem-break.cc | 2 +-
gdbserver/mem-break.h | 4 ++++
gdbserver/server.cc | 7 +++++++
6 files changed, 64 insertions(+), 1 deletion(-)
diff --git a/gdb/NEWS b/gdb/NEWS
index 682def44ce0..8146f695df3 100644
--- a/gdb/NEWS
+++ b/gdb/NEWS
@@ -49,6 +49,10 @@ QThreadOptions in qSupported
QThreadOptions packet, and the qSupported response can contain the
set of thread options the remote stub supports.
+qSupported
+ Gdbserver now reports which types of breakpoints and watchpoints
+ are supported when exchanging features using Z<type>+, Z<type>-.
+
*** Changes in GDB 14
* GDB now supports the AArch64 Scalable Matrix Extension 2 (SME2), which
diff --git a/gdb/doc/gdb.texinfo b/gdb/doc/gdb.texinfo
index e4c00143fd1..20f1906be97 100644
--- a/gdb/doc/gdb.texinfo
+++ b/gdb/doc/gdb.texinfo
@@ -44631,6 +44631,31 @@ These are the currently defined stub features and their properties:
@tab @samp{-}
@tab No
+@item @samp{Z0}
+@tab No
+@tab @samp{-}
+@tab No
+
+@item @samp{Z1}
+@tab No
+@tab @samp{-}
+@tab No
+
+@item @samp{Z2}
+@tab No
+@tab @samp{-}
+@tab No
+
+@item @samp{Z3}
+@tab No
+@tab @samp{-}
+@tab No
+
+@item @samp{Z4}
+@tab No
+@tab @samp{-}
+@tab No
+
@end multitable
These are the currently defined stub features, in more detail:
@@ -44858,6 +44883,13 @@ The remote stub supports and implements the required memory tagging
functionality and understands the @samp{qMemTags} (@pxref{qMemTags}) and
@samp{QMemTags} (@pxref{QMemTags}) packets.
+@item Z@var{type}
+The remote stub reports which types of breakpoints and watchpoints are
+supported. This is done using flags, @samp{Z}@var{type}@samp{+} for supported
+and @samp{Z}@var{type}@samp{-} for unsupported, where @var{type} is one of
+@samp{0}, @samp{1}, @samp{2}, @samp{3}, @samp{4}
+(@pxref{insert breakpoint or watchpoint packet}).
+
For AArch64 GNU/Linux systems, this feature also requires access to the
@file{/proc/@var{pid}/smaps} file so memory mapping page flags can be inspected.
This is done via the @samp{vFile} requests.
diff --git a/gdb/remote.c b/gdb/remote.c
index ce5addade6f..7aa380a5989 100644
--- a/gdb/remote.c
+++ b/gdb/remote.c
@@ -808,6 +808,10 @@ class remote_target : public process_stratum_target
int insert_watchpoint (CORE_ADDR, int, enum target_hw_bp_type,
struct expression *) override;
+ /* Returns true if GDB Z breakpoint type TYPE is supported,
+ false otherwise. */
+ bool supports_z_point_type (int type);
+
int remove_watchpoint (CORE_ADDR, int, enum target_hw_bp_type,
struct expression *) override;
@@ -5717,6 +5721,11 @@ static const struct protocol_feature remote_protocol_features[] = {
{ "no-resumed", PACKET_DISABLE, remote_supported_packet, PACKET_no_resumed },
{ "memory-tagging", PACKET_DISABLE, remote_supported_packet,
PACKET_memory_tagging_feature },
+ { "Z0", PACKET_SUPPORT_UNKNOWN, remote_supported_packet, PACKET_Z0 },
+ { "Z1", PACKET_SUPPORT_UNKNOWN, remote_supported_packet, PACKET_Z1 },
+ { "Z2", PACKET_SUPPORT_UNKNOWN, remote_supported_packet, PACKET_Z2 },
+ { "Z3", PACKET_SUPPORT_UNKNOWN, remote_supported_packet, PACKET_Z3 },
+ { "Z4", PACKET_SUPPORT_UNKNOWN, remote_supported_packet, PACKET_Z4 },
};
static char *remote_support_xml;
@@ -10991,6 +11000,13 @@ watchpoint_to_Z_packet (int type)
}
}
+bool
+remote_target::supports_z_point_type (int type)
+{
+ Z_packet_type packet = watchpoint_to_Z_packet (type);
+ return (m_features.packet_support (PACKET_Z0 + packet) != PACKET_DISABLE);
+}
+
int
remote_target::insert_watchpoint (CORE_ADDR addr, int len,
enum target_hw_bp_type type, struct expression *cond)
diff --git a/gdbserver/mem-break.cc b/gdbserver/mem-break.cc
index 3bee8bc8990..7c3a1d1d47e 100644
--- a/gdbserver/mem-break.cc
+++ b/gdbserver/mem-break.cc
@@ -998,7 +998,7 @@ find_gdb_breakpoint (char z_type, CORE_ADDR addr, int kind)
return NULL;
}
-static int
+int
z_type_supported (char z_type)
{
return (z_type >= '0' && z_type <= '4'
diff --git a/gdbserver/mem-break.h b/gdbserver/mem-break.h
index 9bf7aa84932..b27f0a23ac2 100644
--- a/gdbserver/mem-break.h
+++ b/gdbserver/mem-break.h
@@ -276,4 +276,8 @@ int remove_memory_breakpoint (struct raw_breakpoint *bp);
void clone_all_breakpoints (struct thread_info *child_thread,
const struct thread_info *parent_thread);
+
+/* Returns true if Z_TYPE is supported by the target. */
+
+int z_type_supported (char z_type);
#endif /* GDBSERVER_MEM_BREAK_H */
diff --git a/gdbserver/server.cc b/gdbserver/server.cc
index a8e23561dcb..e727973ad45 100644
--- a/gdbserver/server.cc
+++ b/gdbserver/server.cc
@@ -2613,6 +2613,13 @@ handle_query (char *own_buf, int packet_len, int *new_packet_len_p)
if (target_supports_memory_tagging ())
strcat (own_buf, ";memory-tagging+");
+ /* Z points support. */
+ strcat (own_buf, z_type_supported ('0') ? ";Z0+" : ";Z0-");
+ strcat (own_buf, z_type_supported ('1') ? ";Z1+" : ";Z1-");
+ strcat (own_buf, z_type_supported ('2') ? ";Z2+" : ";Z2-");
+ strcat (own_buf, z_type_supported ('3') ? ";Z3+" : ";Z3-");
+ strcat (own_buf, z_type_supported ('4') ? ";Z4+" : ";Z4-");
+
/* Reinitialize components as needed for the new connection. */
hostio_handle_new_gdb_connection ();
target_handle_new_gdb_connection ();
--
2.25.1
Intel Deutschland GmbH
Registered Address: Am Campeon 10, 85579 Neubiberg, Germany
Tel: +49 89 99 8853-0, www.intel.de <http://www.intel.de>
Managing Directors: Christin Eisenschmid, Sharon Heck, Tiffany Doon Silva
Chairperson of the Supervisory Board: Nicole Lau
Registered Office: Munich
Commercial Register: Amtsgericht Muenchen HRB 186928
^ permalink raw reply [flat|nested] 5+ messages in thread* [PATCH v2 3/3] gdb, zpoint: check for target hardware breakpoint support
2023-11-14 9:20 [PATCH v2 0/3] Check for zpoint support when handling watchpoints Mohamed Bouhaouel
2023-11-14 9:20 ` [PATCH v2 1/3] gdb, gdbserver, zpoint: report z_point support Mohamed Bouhaouel
2023-11-14 9:20 ` [PATCH v2 2/3] gdb, breakpoint: add a breakpoint type converter Mohamed Bouhaouel
@ 2023-11-14 9:20 ` Mohamed Bouhaouel
2 siblings, 0 replies; 5+ messages in thread
From: Mohamed Bouhaouel @ 2023-11-14 9:20 UTC (permalink / raw)
To: gdb-patches; +Cc: blarsen, mohamed.bouhaouel
In 'can_use_hw_breakpoint', check if the target supports
hardware-assisted breakpoints. This will prevent GDB
from trying to insert the hardware breakpoint in case
it is not supported.
Reviewed-By: Guinevere Larsen <blarsen@redhat.com>
---
gdb/remote.c | 28 ++++++++++++++++++++++++----
1 file changed, 24 insertions(+), 4 deletions(-)
diff --git a/gdb/remote.c b/gdb/remote.c
index 7aa380a5989..10504696a57 100644
--- a/gdb/remote.c
+++ b/gdb/remote.c
@@ -10982,7 +10982,7 @@ remote_target::remove_breakpoint (struct gdbarch *gdbarch,
}
static enum Z_packet_type
-watchpoint_to_Z_packet (int type)
+hw_bp_to_Z_packet (int type)
{
switch (type)
{
@@ -10995,6 +10995,9 @@ watchpoint_to_Z_packet (int type)
case hw_access:
return Z_PACKET_ACCESS_WP;
break;
+ case hw_execute:
+ return Z_PACKET_HARDWARE_BP;
+ break;
default:
internal_error (_("hw_bp_to_z: bad watchpoint type %d"), type);
}
@@ -11003,7 +11006,7 @@ watchpoint_to_Z_packet (int type)
bool
remote_target::supports_z_point_type (int type)
{
- Z_packet_type packet = watchpoint_to_Z_packet (type);
+ Z_packet_type packet = hw_bp_to_Z_packet (type);
return (m_features.packet_support (PACKET_Z0 + packet) != PACKET_DISABLE);
}
@@ -11014,7 +11017,7 @@ remote_target::insert_watchpoint (CORE_ADDR addr, int len,
struct remote_state *rs = get_remote_state ();
char *endbuf = rs->buf.data () + get_remote_packet_size ();
char *p;
- enum Z_packet_type packet = watchpoint_to_Z_packet (type);
+ enum Z_packet_type packet = hw_bp_to_Z_packet (type);
if (m_features.packet_support ((to_underlying (PACKET_Z0)
+ to_underlying (packet))) == PACKET_DISABLE)
@@ -11064,7 +11067,7 @@ remote_target::remove_watchpoint (CORE_ADDR addr, int len,
struct remote_state *rs = get_remote_state ();
char *endbuf = rs->buf.data () + get_remote_packet_size ();
char *p;
- enum Z_packet_type packet = watchpoint_to_Z_packet (type);
+ enum Z_packet_type packet = hw_bp_to_Z_packet (type);
if (m_features.packet_support ((to_underlying (PACKET_Z0)
+ to_underlying (packet))) == PACKET_DISABLE)
@@ -11118,6 +11121,11 @@ remote_target::can_use_hw_breakpoint (enum bptype type, int cnt, int ot)
{
if (type == bp_hardware_breakpoint)
{
+ /* Check if the target supports hardware-assisted breakpoints.
+ Return 0 if not. */
+ if (!supports_z_point_type (bptype_to_target_hw_bp_type (type)))
+ return 0;
+
if (remote_hw_breakpoint_limit == 0)
return 0;
else if (remote_hw_breakpoint_limit < 0)
@@ -11127,6 +11135,18 @@ remote_target::can_use_hw_breakpoint (enum bptype type, int cnt, int ot)
}
else
{
+ /* Check if the target supports the hardware watchpoint type.
+ Return 0 if not. */
+ if (!supports_z_point_type (bptype_to_target_hw_bp_type (type)))
+ {
+ /* If hw read watchpoints are not supported while hw access are,
+ GDB will try to insert the watchpoint as hw access. */
+ bool access_support = supports_z_point_type (
+ bptype_to_target_hw_bp_type (bp_access_watchpoint));
+ if (!(type == bp_read_watchpoint && access_support))
+ return 0;
+ }
+
if (remote_hw_watchpoint_limit == 0)
return 0;
else if (remote_hw_watchpoint_limit < 0)
--
2.25.1
Intel Deutschland GmbH
Registered Address: Am Campeon 10, 85579 Neubiberg, Germany
Tel: +49 89 99 8853-0, www.intel.de <http://www.intel.de>
Managing Directors: Christin Eisenschmid, Sharon Heck, Tiffany Doon Silva
Chairperson of the Supervisory Board: Nicole Lau
Registered Office: Munich
Commercial Register: Amtsgericht Muenchen HRB 186928
^ permalink raw reply [flat|nested] 5+ messages in thread