* [PATCH] Return zero in aarch64_linux_can_use_hw_breakpoint if target doesn't support HW watchpoint/breakpoint
@ 2015-07-07 16:30 Yao Qi
2015-07-07 16:36 ` Joel Brobecker
0 siblings, 1 reply; 4+ messages in thread
From: Yao Qi @ 2015-07-07 16:30 UTC (permalink / raw)
To: gdb-patches
Nowadays aarch64_linux_can_use_hw_breakpoint always return one, but it
can be smarter, say, if GDB knows target doesn't support HW watchpoint
or breakpoint because HW watchpoint/breakpoint is disabled in linux
kernel, for example, it can safely return zero.
gdb:
2015-07-07 Yao Qi <yao.qi@linaro.org>
* aarch64-linux-nat.c (aarch64_linux_can_use_hw_breakpoint): If
TYPE is watchpoint, return zero if aarch64_num_wp_regs is zero.
If TYPE is breakpoint, return zero if arch64_num_bp_regs is zero.
---
gdb/aarch64-linux-nat.c | 29 +++++++++++++++++++++--------
1 file changed, 21 insertions(+), 8 deletions(-)
diff --git a/gdb/aarch64-linux-nat.c b/gdb/aarch64-linux-nat.c
index cafd824..2cd20d1 100644
--- a/gdb/aarch64-linux-nat.c
+++ b/gdb/aarch64-linux-nat.c
@@ -1051,19 +1051,32 @@ aarch64_align_watchpoint (CORE_ADDR addr, int len, CORE_ADDR *aligned_addr_p,
bp_read_watchpoint, bp_write_watchpoint, or bp_hardware_breakpoint.
CNT is the number of such watchpoints used so far (including this
one). OTHERTYPE is non-zero if other types of watchpoints are
- currently enabled.
-
- We always return 1 here because we don't have enough information
- about possible overlap of addresses that they want to watch. As an
- extreme example, consider the case where all the watchpoints watch
- the same address and the same region length: then we can handle a
- virtually unlimited number of watchpoints, due to debug register
- sharing implemented via reference counts. */
+ currently enabled. */
static int
aarch64_linux_can_use_hw_breakpoint (struct target_ops *self,
int type, int cnt, int othertype)
{
+ if (type == bp_hardware_watchpoint || type == bp_read_watchpoint
+ || type == bp_access_watchpoint || type == bp_watchpoint)
+ {
+ if (aarch64_num_wp_regs == 0)
+ return 0;
+ }
+ else if (type == bp_hardware_breakpoint)
+ {
+ if (aarch64_num_bp_regs == 0)
+ return 0;
+ }
+ else
+ gdb_assert (FALSE);
+
+ /* We always return 1 here because we don't have enough information
+ about possible overlap of addresses that they want to watch. As an
+ extreme example, consider the case where all the watchpoints watch
+ the same address and the same region length: then we can handle a
+ virtually unlimited number of watchpoints, due to debug register
+ sharing implemented via reference counts. */
return 1;
}
--
1.9.1
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH] Return zero in aarch64_linux_can_use_hw_breakpoint if target doesn't support HW watchpoint/breakpoint
2015-07-07 16:30 [PATCH] Return zero in aarch64_linux_can_use_hw_breakpoint if target doesn't support HW watchpoint/breakpoint Yao Qi
@ 2015-07-07 16:36 ` Joel Brobecker
2015-07-08 8:10 ` Yao Qi
0 siblings, 1 reply; 4+ messages in thread
From: Joel Brobecker @ 2015-07-07 16:36 UTC (permalink / raw)
To: Yao Qi; +Cc: gdb-patches
> + else
> + gdb_assert (FALSE);
Use gdb_assert_not_reached instead?
--
Joel
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH] Return zero in aarch64_linux_can_use_hw_breakpoint if target doesn't support HW watchpoint/breakpoint
2015-07-07 16:36 ` Joel Brobecker
@ 2015-07-08 8:10 ` Yao Qi
2015-07-23 10:23 ` Yao Qi
0 siblings, 1 reply; 4+ messages in thread
From: Yao Qi @ 2015-07-08 8:10 UTC (permalink / raw)
To: Joel Brobecker; +Cc: Yao Qi, gdb-patches
Joel Brobecker <brobecker@adacore.com> writes:
>> + else
>> + gdb_assert (FALSE);
>
> Use gdb_assert_not_reached instead?
Good point. Patch is updated to fix this.
--
Yao (齐尧)
From 79122a045b43a844de70612bf45ad8dee7f218b1 Mon Sep 17 00:00:00 2001
From: Yao Qi <yao.qi@linaro.org>
Date: Fri, 19 Jun 2015 12:21:27 +0100
Subject: [PATCH] Return zero in aarch64_linux_can_use_hw_breakpoint if target doesn't support HW watchpoint/breakpoint
Nowadays aarch64_linux_can_use_hw_breakpoint always return one, but it
can be smarter, say, if GDB knows target doesn't support HW watchpoint
or breakpoint because HW watchpoint/breakpoint is disabled in linux
kernel, for example, it can safely return zero.
gdb:
2015-07-08 Yao Qi <yao.qi@linaro.org>
* aarch64-linux-nat.c (aarch64_linux_can_use_hw_breakpoint): If
TYPE is watchpoint, return zero if aarch64_num_wp_regs is zero.
If TYPE is breakpoint, return zero if arch64_num_bp_regs is zero.
diff --git a/gdb/aarch64-linux-nat.c b/gdb/aarch64-linux-nat.c
index cafd824..d5d0038 100644
--- a/gdb/aarch64-linux-nat.c
+++ b/gdb/aarch64-linux-nat.c
@@ -1051,19 +1051,32 @@ aarch64_align_watchpoint (CORE_ADDR addr, int len, CORE_ADDR *aligned_addr_p,
bp_read_watchpoint, bp_write_watchpoint, or bp_hardware_breakpoint.
CNT is the number of such watchpoints used so far (including this
one). OTHERTYPE is non-zero if other types of watchpoints are
- currently enabled.
-
- We always return 1 here because we don't have enough information
- about possible overlap of addresses that they want to watch. As an
- extreme example, consider the case where all the watchpoints watch
- the same address and the same region length: then we can handle a
- virtually unlimited number of watchpoints, due to debug register
- sharing implemented via reference counts. */
+ currently enabled. */
static int
aarch64_linux_can_use_hw_breakpoint (struct target_ops *self,
int type, int cnt, int othertype)
{
+ if (type == bp_hardware_watchpoint || type == bp_read_watchpoint
+ || type == bp_access_watchpoint || type == bp_watchpoint)
+ {
+ if (aarch64_num_wp_regs == 0)
+ return 0;
+ }
+ else if (type == bp_hardware_breakpoint)
+ {
+ if (aarch64_num_bp_regs == 0)
+ return 0;
+ }
+ else
+ gdb_assert_not_reached ("unexpected breakpoint type");
+
+ /* We always return 1 here because we don't have enough information
+ about possible overlap of addresses that they want to watch. As an
+ extreme example, consider the case where all the watchpoints watch
+ the same address and the same region length: then we can handle a
+ virtually unlimited number of watchpoints, due to debug register
+ sharing implemented via reference counts. */
return 1;
}
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH] Return zero in aarch64_linux_can_use_hw_breakpoint if target doesn't support HW watchpoint/breakpoint
2015-07-08 8:10 ` Yao Qi
@ 2015-07-23 10:23 ` Yao Qi
0 siblings, 0 replies; 4+ messages in thread
From: Yao Qi @ 2015-07-23 10:23 UTC (permalink / raw)
To: Yao Qi; +Cc: gdb-patches
Yao Qi <qiyaoltc@gmail.com> writes:
> gdb:
>
> 2015-07-08 Yao Qi <yao.qi@linaro.org>
>
> * aarch64-linux-nat.c (aarch64_linux_can_use_hw_breakpoint): If
> TYPE is watchpoint, return zero if aarch64_num_wp_regs is zero.
> If TYPE is breakpoint, return zero if arch64_num_bp_regs is zero.
I've pushed it in.
--
Yao (齐尧)
^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2015-07-23 10:23 UTC | newest]
Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2015-07-07 16:30 [PATCH] Return zero in aarch64_linux_can_use_hw_breakpoint if target doesn't support HW watchpoint/breakpoint Yao Qi
2015-07-07 16:36 ` Joel Brobecker
2015-07-08 8:10 ` Yao Qi
2015-07-23 10:23 ` Yao Qi
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).