* [PATCH] uprobes: Add exports for module use
@ 2013-01-10 23:01 Josh Stone
2013-01-11 9:32 ` Christoph Hellwig
0 siblings, 1 reply; 4+ messages in thread
From: Josh Stone @ 2013-01-10 23:01 UTC (permalink / raw)
To: oleg, srikar; +Cc: mingo, peterz, anton, linux-kernel, Josh Stone
The original pull message for uprobes (commit 654443e2) noted:
This tree includes uprobes support in 'perf probe' - but SystemTap
(and other tools) can take advantage of user probe points as well.
In order to actually be usable in module-based tools like SystemTap, the
interface needs to be exported. This patch first adds the obvious
exports for uprobe_register and uprobe_unregister. Then it also adds
one for task_user_regset_view, which is necessary to get the correct
state of userspace registers.
Signed-off-by: Josh Stone <jistone@redhat.com>
---
kernel/events/uprobes.c | 3 +++
kernel/ptrace.c | 7 +++++++
2 files changed, 10 insertions(+)
diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c
index dea7acf..1db8cb6 100644
--- a/kernel/events/uprobes.c
+++ b/kernel/events/uprobes.c
@@ -27,6 +27,7 @@
#include <linux/pagemap.h> /* read_mapping_page */
#include <linux/slab.h>
#include <linux/sched.h>
+#include <linux/export.h>
#include <linux/rmap.h> /* anon_vma_prepare */
#include <linux/mmu_notifier.h> /* set_pte_at_notify */
#include <linux/swap.h> /* try_to_free_swap */
@@ -873,6 +874,7 @@ int uprobe_register(struct inode *inode, loff_t offset, struct uprobe_consumer *
return ret;
}
+EXPORT_SYMBOL_GPL(uprobe_register);
/*
* uprobe_unregister - unregister a already registered probe.
@@ -904,6 +906,7 @@ void uprobe_unregister(struct inode *inode, loff_t offset, struct uprobe_consume
if (uprobe)
put_uprobe(uprobe);
}
+EXPORT_SYMBOL_GPL(uprobe_unregister);
static struct rb_node *
find_node_in_range(struct inode *inode, loff_t min, loff_t max)
diff --git a/kernel/ptrace.c b/kernel/ptrace.c
index 1599157..24eee5d 100644
--- a/kernel/ptrace.c
+++ b/kernel/ptrace.c
@@ -673,6 +673,13 @@ static int ptrace_regset(struct task_struct *task, int req, unsigned int type,
kiov->iov_len, kiov->iov_base);
}
+/*
+ * This is declared in linux/regset.h and defined in machine-dependent
+ * code. We put the export here, near the primary machine-neutral use,
+ * to ensure no machine forgets it.
+ */
+EXPORT_SYMBOL_GPL(task_user_regset_view);
+
#endif
int ptrace_request(struct task_struct *child, long request,
--
1.7.11.7
^ permalink raw reply related [flat|nested] 4+ messages in thread
* Re: [PATCH] uprobes: Add exports for module use
2013-01-10 23:01 [PATCH] uprobes: Add exports for module use Josh Stone
@ 2013-01-11 9:32 ` Christoph Hellwig
2013-01-11 21:42 ` Josh Stone
2013-01-12 16:38 ` Oleg Nesterov
0 siblings, 2 replies; 4+ messages in thread
From: Christoph Hellwig @ 2013-01-11 9:32 UTC (permalink / raw)
To: Josh Stone; +Cc: oleg, srikar, mingo, peterz, anton, linux-kernel
On Thu, Jan 10, 2013 at 03:01:46PM -0800, Josh Stone wrote:
> The original pull message for uprobes (commit 654443e2) noted:
>
> This tree includes uprobes support in 'perf probe' - but SystemTap
> (and other tools) can take advantage of user probe points as well.
>
> In order to actually be usable in module-based tools like SystemTap, the
> interface needs to be exported. This patch first adds the obvious
> exports for uprobe_register and uprobe_unregister. Then it also adds
> one for task_user_regset_view, which is necessary to get the correct
> state of userspace registers.
Get systemtap into the mainline kernel tree and we can talk.
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH] uprobes: Add exports for module use
2013-01-11 9:32 ` Christoph Hellwig
@ 2013-01-11 21:42 ` Josh Stone
2013-01-12 16:38 ` Oleg Nesterov
1 sibling, 0 replies; 4+ messages in thread
From: Josh Stone @ 2013-01-11 21:42 UTC (permalink / raw)
To: Christoph Hellwig; +Cc: oleg, srikar, mingo, peterz, anton, linux-kernel
Hi Christoph,
On 01/11/2013 01:32 AM, Christoph Hellwig wrote:
> On Thu, Jan 10, 2013 at 03:01:46PM -0800, Josh Stone wrote:
>> The original pull message for uprobes (commit 654443e2) noted:
>>
>> This tree includes uprobes support in 'perf probe' - but SystemTap
>> (and other tools) can take advantage of user probe points as well.
I believe this quoted line already signaled the intent that SystemTap
use should be allowed.
> Get systemtap into the mainline kernel tree and we can talk.
This is unlikely to ever happen, nor do I think it's necessarily
appropriate. For instance, we are also developing an alternate mode of
operation that uses Dyninst instead of kernel modules. We're keeping
both modes for their different trade-offs, but in general the tool's
relationship with the kernel is somewhat weaker now.
Thanks,
Josh
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH] uprobes: Add exports for module use
2013-01-11 9:32 ` Christoph Hellwig
2013-01-11 21:42 ` Josh Stone
@ 2013-01-12 16:38 ` Oleg Nesterov
1 sibling, 0 replies; 4+ messages in thread
From: Oleg Nesterov @ 2013-01-12 16:38 UTC (permalink / raw)
To: Christoph Hellwig; +Cc: Josh Stone, srikar, mingo, peterz, anton, linux-kernel
On 01/11, Christoph Hellwig wrote:
>
> On Thu, Jan 10, 2013 at 03:01:46PM -0800, Josh Stone wrote:
> > The original pull message for uprobes (commit 654443e2) noted:
> >
> > This tree includes uprobes support in 'perf probe' - but SystemTap
> > (and other tools) can take advantage of user probe points as well.
> >
> > In order to actually be usable in module-based tools like SystemTap, the
> > interface needs to be exported. This patch first adds the obvious
> > exports for uprobe_register and uprobe_unregister. Then it also adds
> > one for task_user_regset_view, which is necessary to get the correct
> > state of userspace registers.
>
> Get systemtap into the mainline kernel tree and we can talk.
I can't understand your reply.
Looks like, you do not like the fact that uprobes can be used by the out
of tree modules. Why?
And why, say, kprobe_register() is exported then? Afaics, it does not
have any modular in-kernel user.
As for systemtap in particular. I never used it, and probably you didn't.
But it has a lot of users, and I know many people who find it very useful.
Oleg.
^ permalink raw reply [flat|nested] 4+ messages in thread
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2013-01-10 23:01 [PATCH] uprobes: Add exports for module use Josh Stone
2013-01-11 9:32 ` Christoph Hellwig
2013-01-11 21:42 ` Josh Stone
2013-01-12 16:38 ` Oleg Nesterov
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