Re: [PATCH 2/4] HWPOISON: Copy si_addr_lsb to user

Hidetoshi Seto
2010-10-07T06:32:08Z

(2010/10/07 5:48), Andi Kleen wrote:
> From: Andi Kleen <ak@linux.intel.com>
>
> The original hwpoison code added a new siginfo field si_addr_lsb to
> pass the granuality of the fault address to user space. Unfortunately
> this field was never copied to user space. Fix this here.
>
> I added explicit checks for the MCEERR codes to avoid having
> to patch all potential callers to initialize the field.

Now QEMU uses signalfd to catch the SIGBUS delivered to the
main thread, so I think similar fix to copy lsb to user is
required for signalfd too.

Thanks,
H.Seto

=====

From: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Subject: [PATCH] signalfd: add support addr_lsb

Signed-off-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
---
fs/signalfd.c | 10 ++++++++++
include/linux/signalfd.h | 3 ++-
2 files changed, 12 insertions(+), 1 deletions(-)

diff --git a/fs/signalfd.c b/fs/signalfd.c
index 1c5a6ad..3e28173 100644
--- a/fs/signalfd.c
+++ b/fs/signalfd.c
@@ -99,6 +99,16 @@ static int signalfd_copyinfo(struct signalfd_siginfo __user *uinfo,
#ifdef __ARCH_SI_TRAPNO
err |= __put_user(kinfo->si_trapno, &uinfo->ssi_trapno);
#endif
+#ifdef BUS_MCEERR_AO
+ /*
+ * Other callers might not initialize the si_lsb field,
+ * so check explicitely for the right codes here.
+ */
+ if (kinfo->si_code == BUS_MCEERR_AR ||
+ kinfo->si_code == BUS_MCEERR_AO)
+ err |= __put_user((short) kinfo->si_addr_lsb,
+ &uinfo->ssi_addr_lsb);
+#endif
break;
case __SI_CHLD:
err |= __put_user(kinfo->si_pid, &uinfo->ssi_pid);
diff --git a/include/linux/signalfd.h b/include/linux/signalfd.h
index b363b91..3ff4961 100644
--- a/include/linux/signalfd.h
+++ b/include/linux/signalfd.h
@@ -33,6 +33,7 @@ struct signalfd_siginfo {
__u64 ssi_utime;
__u64 ssi_stime;
__u64 ssi_addr;
+ __u16 ssi_addr_lsb;

/*
* Pad strcture to 128 bytes. Remember to update the
@@ -43,7 +44,7 @@ struct signalfd_siginfo {
* comes out of a read(2) and we really don't want to have
* a compat on read(2).
*/
- __u8 __pad[48];
+ __u8 __pad[46];
};

--
1.7.3.1