Re: [PATCH] Add compat_sys_preadv64v2/compat_sys_pwritev64v2

From: H.J. Lu
Date: Thu Jul 14 2016 - 15:32:00 EST


On Thu, Jul 14, 2016 at 12:01 PM, Ingo Molnar <mingo@xxxxxxxxxx> wrote:
>
> * H.J. Lu <hjl.tools@xxxxxxxxx> wrote:
>
>> Add compat_sys_preadv64v2 and compat_sys_pwritev64v2 so that 64-bit offset
>> is passed in one 64-bit register on x32, similar to compat_sys_preadv64
>> and compat_sys_pwritev64.
>>
>> Signed-off-by: H.J. Lu <hjl.tools@xxxxxxxxx>
>
>> From 100f17970625dfeb27539a4bb2470acefe3982e1 Mon Sep 17 00:00:00 2001
>> From: "H.J. Lu" <hjl.tools@xxxxxxxxx>
>> Date: Thu, 14 Jul 2016 08:42:12 -0700
>> Subject: [PATCH] Add compat_sys_preadv64v2/compat_sys_pwritev64v2
>>
>> Add compat_sys_preadv64v2 and compat_sys_pwritev64v2 so that 64-bit offset
>> is passed in one 64-bit register on x32, similar to compat_sys_preadv64
>> and compat_sys_pwritev64.
>>
>> Signed-off-by: H.J. Lu <hjl.tools@xxxxxxxxx>
>> ---
>> arch/x86/entry/syscalls/syscall_64.tbl | 2 ++
>> arch/x86/include/asm/unistd.h | 2 ++
>> fs/read_write.c | 18 ++++++++++++++++++
>> 3 files changed, 22 insertions(+)
>
> Could you please send this against the latest upstream kernel, such as v4.7-rc7?
> The patch does not apply cleanly:
>
> patching file arch/x86/entry/syscalls/syscall_64.tbl
> Hunk #1 FAILED at 374.
> 1 out of 1 hunk FAILED -- rejects in file arch/x86/entry/syscalls/syscall_64.tbl
> patching file arch/x86/include/asm/unistd.h
> patching file fs/read_write.c
> Hunk #1 succeeded at 1168 (offset -14 lines).
> Hunk #2 succeeded at 1274 (offset -14 lines).
>
> Also, could you please Cc: linux-kernel@xxxxxxxxxxxxxxx to patch submissions?
>
> Thanks,

Here is the updated patch.

--
H.J.
From a5819cd3ca58291067526b7430b3109fefa4e8b1 Mon Sep 17 00:00:00 2001
From: "H.J. Lu" <hjl.tools@xxxxxxxxx>
Date: Thu, 14 Jul 2016 08:42:12 -0700
Subject: [PATCH] Add compat_sys_preadv64v2/compat_sys_pwritev64v2

Don't use the same syscall numbers for 2 different syscalls:

534 x32 preadv compat_sys_preadv64
535 x32 pwritev compat_sys_pwritev64
534 x32 preadv2 compat_sys_preadv2
535 x32 pwritev2 compat_sys_pwritev2

Add compat_sys_preadv64v2 and compat_sys_pwritev64v2 so that 64-bit offset
is passed in one 64-bit register on x32, similar to compat_sys_preadv64
and compat_sys_pwritev64.

Signed-off-by: H.J. Lu <hjl.tools@xxxxxxxxx>
---
arch/x86/entry/syscalls/syscall_64.tbl | 4 ++--
arch/x86/include/asm/unistd.h | 2 ++
fs/read_write.c | 18 ++++++++++++++++++
3 files changed, 22 insertions(+), 2 deletions(-)

diff --git a/arch/x86/entry/syscalls/syscall_64.tbl b/arch/x86/entry/syscalls/syscall_64.tbl
index 555263e..e9ce9c7 100644
--- a/arch/x86/entry/syscalls/syscall_64.tbl
+++ b/arch/x86/entry/syscalls/syscall_64.tbl
@@ -374,5 +374,5 @@
543 x32 io_setup compat_sys_io_setup
544 x32 io_submit compat_sys_io_submit
545 x32 execveat compat_sys_execveat/ptregs
-534 x32 preadv2 compat_sys_preadv2
-535 x32 pwritev2 compat_sys_pwritev2
+546 x32 preadv2 compat_sys_preadv64v2
+547 x32 pwritev2 compat_sys_pwritev64v2
diff --git a/arch/x86/include/asm/unistd.h b/arch/x86/include/asm/unistd.h
index 2b19caa..32712a9 100644
--- a/arch/x86/include/asm/unistd.h
+++ b/arch/x86/include/asm/unistd.h
@@ -26,6 +26,8 @@
# define __ARCH_WANT_COMPAT_SYS_GETDENTS64
# define __ARCH_WANT_COMPAT_SYS_PREADV64
# define __ARCH_WANT_COMPAT_SYS_PWRITEV64
+# define __ARCH_WANT_COMPAT_SYS_PREADV64V2
+# define __ARCH_WANT_COMPAT_SYS_PWRITEV64V2

# endif

diff --git a/fs/read_write.c b/fs/read_write.c
index 933b53a..66215a7 100644
--- a/fs/read_write.c
+++ b/fs/read_write.c
@@ -1168,6 +1168,15 @@ COMPAT_SYSCALL_DEFINE5(preadv, compat_ulong_t, fd,
return do_compat_preadv64(fd, vec, vlen, pos, 0);
}

+#ifdef __ARCH_WANT_COMPAT_SYS_PREADV64V2
+COMPAT_SYSCALL_DEFINE5(preadv64v2, unsigned long, fd,
+ const struct compat_iovec __user *,vec,
+ unsigned long, vlen, loff_t, pos, int, flags)
+{
+ return do_compat_preadv64(fd, vec, vlen, pos, flags);
+}
+#endif
+
COMPAT_SYSCALL_DEFINE6(preadv2, compat_ulong_t, fd,
const struct compat_iovec __user *,vec,
compat_ulong_t, vlen, u32, pos_low, u32, pos_high,
@@ -1265,6 +1274,15 @@ COMPAT_SYSCALL_DEFINE5(pwritev, compat_ulong_t, fd,
return do_compat_pwritev64(fd, vec, vlen, pos, 0);
}

+#ifdef __ARCH_WANT_COMPAT_SYS_PWRITEV64V2
+COMPAT_SYSCALL_DEFINE5(pwritev64v2, unsigned long, fd,
+ const struct compat_iovec __user *,vec,
+ unsigned long, vlen, loff_t, pos, int, flags)
+{
+ return do_compat_pwritev64(fd, vec, vlen, pos, flags);
+}
+#endif
+
COMPAT_SYSCALL_DEFINE6(pwritev2, compat_ulong_t, fd,
const struct compat_iovec __user *,vec,
compat_ulong_t, vlen, u32, pos_low, u32, pos_high, int, flags)
--
2.7.4