2019-12-13 21:01:08

by Arnd Bergmann

Subject: [PATCH v2 24/24] y2038: sparc: remove use of struct timex

'struct timex' is one of the last users of 'struct timeval' and is
only referenced in one place in the kernel any more, to convert the
user space timex into the kernel-internal version on sparc64, with a
different tv_usec member type.

As a preparation for hiding the time_t definition and everything
using that in the kernel, change the implementation once more
to only convert the timeval member, and then enclose the
struct definition in an #ifdef.

Signed-off-by: Arnd Bergmann <[email protected]>
---
arch/sparc/kernel/sys_sparc_64.c | 29 +++++++++++++++--------------
include/uapi/linux/timex.h | 2 ++
2 files changed, 17 insertions(+), 14 deletions(-)

diff --git a/arch/sparc/kernel/sys_sparc_64.c b/arch/sparc/kernel/sys_sparc_64.c
index 9f41a6f5a032..1c85b0af4dfd 100644
--- a/arch/sparc/kernel/sys_sparc_64.c
+++ b/arch/sparc/kernel/sys_sparc_64.c
@@ -548,34 +548,35 @@ SYSCALL_DEFINE2(getdomainname, char __user *, name, int, len)
return err;
}

-SYSCALL_DEFINE1(sparc_adjtimex, struct timex __user *, txc_p)
+SYSCALL_DEFINE1(sparc_adjtimex, struct __kernel_timex __user *, txc_p)
{
- struct timex txc; /* Local copy of parameter */
- struct __kernel_timex *kt = (void *)&txc;
+ struct __kernel_timex txc;
+ __kernel_old_timeval *tv = (void *)&txc->time;
int ret;

/* Copy the user data space into the kernel copy
* structure. But bear in mind that the structures
* may change
*/
- if (copy_from_user(&txc, txc_p, sizeof(struct timex)))
+ if (copy_from_user(&txc, txc_p, sizeof(txc)))
return -EFAULT;

/*
* override for sparc64 specific timeval type: tv_usec
* is 32 bit wide instead of 64-bit in __kernel_timex
*/
- kt->time.tv_usec = txc.time.tv_usec;
+ kt->time.tv_usec = tv->tv_usec;
ret = do_adjtimex(kt);
- txc.time.tv_usec = kt->time.tv_usec;
+ tv->tv_usec = kt->time.tv_usec;

- return copy_to_user(txc_p, &txc, sizeof(struct timex)) ? -EFAULT : ret;
+ return copy_to_user(txc_p, &txc, sizeof(txc)) ? -EFAULT : ret;
}

-SYSCALL_DEFINE2(sparc_clock_adjtime, const clockid_t, which_clock,struct timex __user *, txc_p)
+SYSCALL_DEFINE2(sparc_clock_adjtime, const clockid_t, which_clock,
+ struct __kernel_timex __user *, txc_p)
{
- struct timex txc; /* Local copy of parameter */
- struct __kernel_timex *kt = (void *)&txc;
+ struct __kernel_timex txc;
+ __kernel_old_timeval *tv = (void *)&txc->time;
int ret;

if (!IS_ENABLED(CONFIG_POSIX_TIMERS)) {
@@ -590,18 +591,18 @@ SYSCALL_DEFINE2(sparc_clock_adjtime, const clockid_t, which_clock,struct timex _
* structure. But bear in mind that the structures
* may change
*/
- if (copy_from_user(&txc, txc_p, sizeof(struct timex)))
+ if (copy_from_user(&txc, txc_p, sizeof(txc)))
return -EFAULT;

/*
* override for sparc64 specific timeval type: tv_usec
* is 32 bit wide instead of 64-bit in __kernel_timex
*/
- kt->time.tv_usec = txc.time.tv_usec;
+ kt->time.tv_usec = tv->tv_usec;
ret = do_clock_adjtime(which_clock, kt);
- txc.time.tv_usec = kt->time.tv_usec;
+ tv->tv_usec = kt->time.tv_usec;

- return copy_to_user(txc_p, &txc, sizeof(struct timex)) ? -EFAULT : ret;
+ return copy_to_user(txc_p, &txc, sizeof(txc)) ? -EFAULT : ret;
}

SYSCALL_DEFINE5(utrap_install, utrap_entry_t, type,
diff --git a/include/uapi/linux/timex.h b/include/uapi/linux/timex.h
index 9f517f9010bb..bd627c368d09 100644
--- a/include/uapi/linux/timex.h
+++ b/include/uapi/linux/timex.h
@@ -57,6 +57,7 @@

#define NTP_API 4 /* NTP API version */

+#ifndef __KERNEL__
/*
* syscall interface - used (mainly by NTP daemon)
* to discipline kernel clock oscillator
@@ -91,6 +92,7 @@ struct timex {
int :32; int :32; int :32; int :32;
int :32; int :32; int :32;
};
+#endif

struct __kernel_timex_timeval {
__kernel_time64_t tv_sec;
--
2.20.0

2019-12-14 01:41:39

by Julian Calaby

Subject: Re: [PATCH v2 24/24] y2038: sparc: remove use of struct timex

Hi Arnd,

On Sat, Dec 14, 2019 at 7:59 AM Arnd Bergmann <[email protected]> wrote:
>
> 'struct timex' is one of the last users of 'struct timeval' and is
> only referenced in one place in the kernel any more, to convert the
> user space timex into the kernel-internal version on sparc64, with a
> different tv_usec member type.
>
> As a preparation for hiding the time_t definition and everything
> using that in the kernel, change the implementation once more
> to only convert the timeval member, and then enclose the
> struct definition in an #ifdef.
>
> Signed-off-by: Arnd Bergmann <[email protected]>
> ---
> arch/sparc/kernel/sys_sparc_64.c | 29 +++++++++++++++--------------
> include/uapi/linux/timex.h | 2 ++
> 2 files changed, 17 insertions(+), 14 deletions(-)
>
> diff --git a/arch/sparc/kernel/sys_sparc_64.c b/arch/sparc/kernel/sys_sparc_64.c
> index 9f41a6f5a032..1c85b0af4dfd 100644
> --- a/arch/sparc/kernel/sys_sparc_64.c
> +++ b/arch/sparc/kernel/sys_sparc_64.c
> @@ -548,34 +548,35 @@ SYSCALL_DEFINE2(getdomainname, char __user *, name, int, len)
> return err;
> }
>
> -SYSCALL_DEFINE1(sparc_adjtimex, struct timex __user *, txc_p)
> +SYSCALL_DEFINE1(sparc_adjtimex, struct __kernel_timex __user *, txc_p)
> {
> - struct timex txc; /* Local copy of parameter */
> - struct __kernel_timex *kt = (void *)&txc;
> + struct __kernel_timex txc;
> + __kernel_old_timeval *tv = (void *)&txc->time;
> int ret;
>
> /* Copy the user data space into the kernel copy
> * structure. But bear in mind that the structures
> * may change
> */
> - if (copy_from_user(&txc, txc_p, sizeof(struct timex)))
> + if (copy_from_user(&txc, txc_p, sizeof(txc)))
> return -EFAULT;
>
> /*
> * override for sparc64 specific timeval type: tv_usec
> * is 32 bit wide instead of 64-bit in __kernel_timex
> */
> - kt->time.tv_usec = txc.time.tv_usec;
> + kt->time.tv_usec = tv->tv_usec;

Am I mis-reading the patch, or is "kt" not defined?

Thanks,

--
Julian Calaby

Email: [email protected]
Profile: http://www.google.com/profiles/julian.calaby/

2019-12-14 14:45:39

by Arnd Bergmann

Subject: Re: [Y2038] [PATCH v2 24/24] y2038: sparc: remove use of struct timex

On Sat, Dec 14, 2019 at 2:38 AM Julian Calaby <[email protected]> wrote:
> On Sat, Dec 14, 2019 at 7:59 AM Arnd Bergmann <[email protected]> wrote:
>
> Am I mis-reading the patch, or is "kt" not defined?

You are right, and there are other problems in this patch that I should have
found in a trivial compile-test. Please disregard this patch, it should not have
been part of this set before I had gotten around to at least some testing.

When I collected stuff from my backlog, I only made sure that this one had
no dependencies on other work, but failed to realize that sparc64 was not
part of my build test matrix and that the 0day bot had not seen it either.

Arnd