* [PATCH v2] arm64/debug: Fix registers on sleeping tasks
@ 2018-03-05 23:43 Douglas Anderson
2018-03-08 16:19 ` Daniel Thompson
0 siblings, 1 reply; 4+ messages in thread
From: Douglas Anderson @ 2018-03-05 23:43 UTC (permalink / raw)
To: linux-arm-kernel
This is the equivalent of commit 001bf455d206 ("ARM: 8428/1: kgdb: Fix
registers on sleeping tasks") but for arm64. Nuff said.
...well, perhaps I could also add that task_pt_regs are userspace
registers and that's not what kgdb is supposed to be reporting. We're
supposed to be reporting kernel registers.
Signed-off-by: Douglas Anderson <dianders@chromium.org>
---
Changes in v2:
- Init cpu_context in one line
- Explain that task_pt_regs are userspace
arch/arm64/kernel/kgdb.c | 21 ++++++++++++++++-----
1 file changed, 16 insertions(+), 5 deletions(-)
diff --git a/arch/arm64/kernel/kgdb.c b/arch/arm64/kernel/kgdb.c
index 2122cd187f19..a20de58061a8 100644
--- a/arch/arm64/kernel/kgdb.c
+++ b/arch/arm64/kernel/kgdb.c
@@ -138,14 +138,25 @@ int dbg_set_reg(int regno, void *mem, struct pt_regs *regs)
void
sleeping_thread_to_gdb_regs(unsigned long *gdb_regs, struct task_struct *task)
{
- struct pt_regs *thread_regs;
+ struct cpu_context *cpu_context = &task->thread.cpu_context;
/* Initialize to zero */
memset((char *)gdb_regs, 0, NUMREGBYTES);
- thread_regs = task_pt_regs(task);
- memcpy((void *)gdb_regs, (void *)thread_regs->regs, GP_REG_BYTES);
- /* Special case for PSTATE (check comments in asm/kgdb.h for details) */
- dbg_get_reg(33, gdb_regs + GP_REG_BYTES, thread_regs);
+
+ gdb_regs[19] = cpu_context->x19;
+ gdb_regs[20] = cpu_context->x20;
+ gdb_regs[21] = cpu_context->x21;
+ gdb_regs[22] = cpu_context->x22;
+ gdb_regs[23] = cpu_context->x23;
+ gdb_regs[24] = cpu_context->x24;
+ gdb_regs[25] = cpu_context->x25;
+ gdb_regs[26] = cpu_context->x26;
+ gdb_regs[27] = cpu_context->x27;
+ gdb_regs[28] = cpu_context->x28;
+ gdb_regs[29] = cpu_context->fp;
+
+ gdb_regs[31] = cpu_context->sp;
+ gdb_regs[32] = cpu_context->pc;
}
void kgdb_arch_set_pc(struct pt_regs *regs, unsigned long pc)
--
2.16.2.395.g2e18187dfd-goog
^ permalink raw reply related [flat|nested] 4+ messages in thread* [PATCH v2] arm64/debug: Fix registers on sleeping tasks
2018-03-05 23:43 [PATCH v2] arm64/debug: Fix registers on sleeping tasks Douglas Anderson
@ 2018-03-08 16:19 ` Daniel Thompson
2018-03-08 16:41 ` Doug Anderson
0 siblings, 1 reply; 4+ messages in thread
From: Daniel Thompson @ 2018-03-08 16:19 UTC (permalink / raw)
To: linux-arm-kernel
On 05/03/18 23:43, Douglas Anderson wrote:
> This is the equivalent of commit 001bf455d206 ("ARM: 8428/1: kgdb: Fix
> registers on sleeping tasks") but for arm64. Nuff said.
>
> ...well, perhaps I could also add that task_pt_regs are userspace
> registers and that's not what kgdb is supposed to be reporting. We're
> supposed to be reporting kernel registers.
>
> Signed-off-by: Douglas Anderson <dianders@chromium.org>
I hacked together a (still very immature) kgdb test suite[1] around the
turn of the year. Whilst its not quite solid enough for me to recommend
others deploy it except out of curiosity... so I haven't yet started
yelling about test suite failures except in the privacy of my own head.
However I can confirm that this patch fixes one of the test suite
failures I haven't had time to blame allocate yet!
So...
Tested-by: Daniel Thompson <daniel.thompson@linaro.org>
BTW is this something that should Cc: stable?
Daniel.
[1] https://github.com/daniel-thompson/kgdbtest
> ---
>
> Changes in v2:
> - Init cpu_context in one line
> - Explain that task_pt_regs are userspace
>
> arch/arm64/kernel/kgdb.c | 21 ++++++++++++++++-----
> 1 file changed, 16 insertions(+), 5 deletions(-)
>
> diff --git a/arch/arm64/kernel/kgdb.c b/arch/arm64/kernel/kgdb.c
> index 2122cd187f19..a20de58061a8 100644
> --- a/arch/arm64/kernel/kgdb.c
> +++ b/arch/arm64/kernel/kgdb.c
> @@ -138,14 +138,25 @@ int dbg_set_reg(int regno, void *mem, struct pt_regs *regs)
> void
> sleeping_thread_to_gdb_regs(unsigned long *gdb_regs, struct task_struct *task)
> {
> - struct pt_regs *thread_regs;
> + struct cpu_context *cpu_context = &task->thread.cpu_context;
>
> /* Initialize to zero */
> memset((char *)gdb_regs, 0, NUMREGBYTES);
> - thread_regs = task_pt_regs(task);
> - memcpy((void *)gdb_regs, (void *)thread_regs->regs, GP_REG_BYTES);
> - /* Special case for PSTATE (check comments in asm/kgdb.h for details) */
> - dbg_get_reg(33, gdb_regs + GP_REG_BYTES, thread_regs);
> +
> + gdb_regs[19] = cpu_context->x19;
> + gdb_regs[20] = cpu_context->x20;
> + gdb_regs[21] = cpu_context->x21;
> + gdb_regs[22] = cpu_context->x22;
> + gdb_regs[23] = cpu_context->x23;
> + gdb_regs[24] = cpu_context->x24;
> + gdb_regs[25] = cpu_context->x25;
> + gdb_regs[26] = cpu_context->x26;
> + gdb_regs[27] = cpu_context->x27;
> + gdb_regs[28] = cpu_context->x28;
> + gdb_regs[29] = cpu_context->fp;
> +
> + gdb_regs[31] = cpu_context->sp;
> + gdb_regs[32] = cpu_context->pc;
> }
>
> void kgdb_arch_set_pc(struct pt_regs *regs, unsigned long pc)
>
^ permalink raw reply [flat|nested] 4+ messages in thread* [PATCH v2] arm64/debug: Fix registers on sleeping tasks
2018-03-08 16:19 ` Daniel Thompson
@ 2018-03-08 16:41 ` Doug Anderson
2018-03-08 16:43 ` Will Deacon
0 siblings, 1 reply; 4+ messages in thread
From: Doug Anderson @ 2018-03-08 16:41 UTC (permalink / raw)
To: linux-arm-kernel
Hi,
On Thu, Mar 8, 2018 at 8:19 AM, Daniel Thompson
<daniel.thompson@linaro.org> wrote:
> On 05/03/18 23:43, Douglas Anderson wrote:
>>
>> This is the equivalent of commit 001bf455d206 ("ARM: 8428/1: kgdb: Fix
>> registers on sleeping tasks") but for arm64. Nuff said.
>>
>> ...well, perhaps I could also add that task_pt_regs are userspace
>> registers and that's not what kgdb is supposed to be reporting. We're
>> supposed to be reporting kernel registers.
>>
>> Signed-off-by: Douglas Anderson <dianders@chromium.org>
>
>
> I hacked together a (still very immature) kgdb test suite[1] around the turn
> of the year. Whilst its not quite solid enough for me to recommend others
> deploy it except out of curiosity... so I haven't yet started yelling about
> test suite failures except in the privacy of my own head.
>
> However I can confirm that this patch fixes one of the test suite failures I
> haven't had time to blame allocate yet!
>
> So...
> Tested-by: Daniel Thompson <daniel.thompson@linaro.org>
Thanks for your testing! ...I'll have to check out your test suite soon.
> BTW is this something that should Cc: stable?
It wouldn't hurt if this made it back to stable on a best-effort
approach. The problem has been there since the beginning, so it's not
like it's fixing a regression that cropped up in a specific version.
...but it does fix a bug, so probably Cc stable makes sense. I guess
I'd leave it up to the maintainer that applies the patch?
-Doug<div class="gmail_extra"><br><div class="gmail_quote">On Thu, Mar
8, 2018 at 8:19 AM, Daniel Thompson <span dir="ltr"><<a
href="mailto:daniel.thompson@linaro.org"
target="_blank">daniel.thompson at linaro.org</a>></span>
wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0
.8ex;border-left:1px #ccc solid;padding-left:1ex"><span class="">On
05/03/18 23:43, Douglas Anderson wrote:<br>
<blockquote class="gmail_quote" style="margin:0 0 0
.8ex;border-left:1px #ccc solid;padding-left:1ex">
This is the equivalent of commit 001bf455d206 ("ARM: 8428/1: kgdb: Fix<br>
registers on sleeping tasks") but for arm64. Nuff said.<br>
<br>
...well, perhaps I could also add that task_pt_regs are userspace<br>
registers and that's not what kgdb is supposed to be reporting. We're<br>
supposed to be reporting kernel registers.<br>
<br>
Signed-off-by: Douglas Anderson <<a
href="mailto:dianders@chromium.org"
target="_blank">dianders at chromium.org</a>><br>
</blockquote>
<br></span>
I hacked together a (still very immature) kgdb test suite[1] around
the turn of the year. Whilst its not quite solid enough for me to
recommend others deploy it except out of curiosity... so I haven't yet
started yelling about test suite failures except in the privacy of my
own head.<br>
<br>
However I can confirm that this patch fixes one of the test suite
failures I haven't had time to blame allocate yet!<br>
<br>
So...<br>
Tested-by: Daniel Thompson <<a
href="mailto:daniel.thompson@linaro.org"
target="_blank">daniel.thompson at linaro.org</a>><br>
<br>
BTW is this something that should Cc: stable?<br>
<br>
<br>
Daniel.<br>
<br>
[1] <a href="https://github.com/daniel-thompson/kgdbtest"
rel="noreferrer" target="_blank"
data-saferedirecturl="https://www.google.com/url?hl=en&q=https://github.com/daniel-thompson/kgdbtest&source=gmail&ust=1520613443900000&usg=AFQjCNHzh_tGdP65DdFEQo-ofF_LCI5XBQ">https://github.com/daniel-thom<wbr>pson/kgdbtest</a><div
class="HOEnZb"><div class="h5"><br>
<br>
<br>
<blockquote class="gmail_quote" style="margin:0 0 0
.8ex;border-left:1px #ccc solid;padding-left:1ex">
---<br>
<br>
Changes in v2:<br>
- Init cpu_context in one line<br>
- Explain that task_pt_regs are userspace<br>
<br>
arch/arm64/kernel/kgdb.c | 21 ++++++++++++++++-----<br>
1 file changed, 16 insertions(+), 5 deletions(-)<br>
<br>
diff --git a/arch/arm64/kernel/kgdb.c b/arch/arm64/kernel/kgdb.c<br>
index 2122cd187f19..a20de58061a8 100644<br>
--- a/arch/arm64/kernel/kgdb.c<br>
+++ b/arch/arm64/kernel/kgdb.c<br>
@@ -138,14 +138,25 @@ int dbg_set_reg(int regno, void *mem, struct
pt_regs *regs)<br>
void<br>
sleeping_thread_to_gdb_regs(un<wbr>signed long *gdb_regs,
struct task_struct *task)<br>
{<br>
- struct pt_regs *thread_regs;<br>
+ struct cpu_context *cpu_context =
&task->thread.cpu_context;<br>
/* Initialize to zero */<br>
memset((char *)gdb_regs, 0, NUMREGBYTES);<br>
- thread_regs = task_pt_regs(task);<br>
- memcpy((void *)gdb_regs, (void
*)thread_regs->regs, GP_REG_BYTES);<br>
- /* Special case for PSTATE (check comments
in asm/kgdb.h for details) */<br>
- dbg_get_reg(33, gdb_regs + GP_REG_BYTES,
thread_regs);<br>
+<br>
+ gdb_regs[19] = cpu_context->x19;<br>
+ gdb_regs[20] = cpu_context->x20;<br>
+ gdb_regs[21] = cpu_context->x21;<br>
+ gdb_regs[22] = cpu_context->x22;<br>
+ gdb_regs[23] = cpu_context->x23;<br>
+ gdb_regs[24] = cpu_context->x24;<br>
+ gdb_regs[25] = cpu_context->x25;<br>
+ gdb_regs[26] = cpu_context->x26;<br>
+ gdb_regs[27] = cpu_context->x27;<br>
+ gdb_regs[28] = cpu_context->x28;<br>
+ gdb_regs[29] = cpu_context->fp;<br>
+<br>
+ gdb_regs[31] = cpu_context->sp;<br>
+ gdb_regs[32] = cpu_context->pc;<br>
}<br>
void kgdb_arch_set_pc(struct pt_regs *regs, unsigned long pc)<br>
<br>
</blockquote>
<br>
</div></div></blockquote></div><br></div>
^ permalink raw reply related [flat|nested] 4+ messages in thread* [PATCH v2] arm64/debug: Fix registers on sleeping tasks
2018-03-08 16:41 ` Doug Anderson
@ 2018-03-08 16:43 ` Will Deacon
0 siblings, 0 replies; 4+ messages in thread
From: Will Deacon @ 2018-03-08 16:43 UTC (permalink / raw)
To: linux-arm-kernel
On Thu, Mar 08, 2018 at 08:41:59AM -0800, Doug Anderson wrote:
> Hi,
>
> On Thu, Mar 8, 2018 at 8:19 AM, Daniel Thompson
> <daniel.thompson@linaro.org> wrote:
> > On 05/03/18 23:43, Douglas Anderson wrote:
> >>
> >> This is the equivalent of commit 001bf455d206 ("ARM: 8428/1: kgdb: Fix
> >> registers on sleeping tasks") but for arm64. Nuff said.
> >>
> >> ...well, perhaps I could also add that task_pt_regs are userspace
> >> registers and that's not what kgdb is supposed to be reporting. We're
> >> supposed to be reporting kernel registers.
> >>
> >> Signed-off-by: Douglas Anderson <dianders@chromium.org>
> >
> >
> > I hacked together a (still very immature) kgdb test suite[1] around the turn
> > of the year. Whilst its not quite solid enough for me to recommend others
> > deploy it except out of curiosity... so I haven't yet started yelling about
> > test suite failures except in the privacy of my own head.
> >
> > However I can confirm that this patch fixes one of the test suite failures I
> > haven't had time to blame allocate yet!
> >
> > So...
> > Tested-by: Daniel Thompson <daniel.thompson@linaro.org>
>
> Thanks for your testing! ...I'll have to check out your test suite soon.
>
>
> > BTW is this something that should Cc: stable?
>
> It wouldn't hurt if this made it back to stable on a best-effort
> approach. The problem has been there since the beginning, so it's not
> like it's fixing a regression that cropped up in a specific version.
> ...but it does fix a bug, so probably Cc stable makes sense. I guess
> I'd leave it up to the maintainer that applies the patch?
I've already put this into -next, so I don't really want to rebase just for
this. If you think it's important, please send to stable at vger.kernel.org
once it's landed in mainline.
Will
^ permalink raw reply [flat|nested] 4+ messages in thread
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2018-03-05 23:43 [PATCH v2] arm64/debug: Fix registers on sleeping tasks Douglas Anderson
2018-03-08 16:19 ` Daniel Thompson
2018-03-08 16:41 ` Doug Anderson
2018-03-08 16:43 ` Will Deacon
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