[PATCH 07/23] y2038: vdso: powerpc: avoid timespec references

From: Arnd Bergmann
Date: Fri Nov 08 2019 - 16:11:25 EST

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As a preparation to stop using 'struct timespec' in the kernel,
change the powerpc vdso implementation:

- split up the vdso data definition to have equivalent members
for seconds and nanoseconds instead of an xtime structure

- use timespec64 as an intermediate for the xtime update

- change the asm-offsets definition to be based the appropriate
fixed-length types

This is only a temporary fix for changing the types, in order
to actually support a 64-bit safe vdso32 version of clock_gettime(),
the entire powerpc vdso should be replaced with the generic
lib/vdso/ implementation. If that happens first, this patch
becomes obsolete.

Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
---
arch/powerpc/include/asm/vdso_datapage.h | 6 ++++--
arch/powerpc/kernel/asm-offsets.c | 14 +++++---------
arch/powerpc/kernel/time.c | 5 +++--
arch/powerpc/kernel/vdso32/gettimeofday.S | 6 ++----
arch/powerpc/kernel/vdso64/gettimeofday.S | 8 ++++----
5 files changed, 18 insertions(+), 21 deletions(-)

diff --git a/arch/powerpc/include/asm/vdso_datapage.h b/arch/powerpc/include/asm/vdso_datapage.h
index c61d59ed3b45..a115970a6809 100644
--- a/arch/powerpc/include/asm/vdso_datapage.h
+++ b/arch/powerpc/include/asm/vdso_datapage.h
@@ -81,7 +81,8 @@ struct vdso_data {
__u32 stamp_sec_fraction; /* fractional seconds of stamp_xtime */
__s32 wtom_clock_nsec; /* Wall to monotonic clock nsec */
__s64 wtom_clock_sec; /* Wall to monotonic clock sec */
- struct timespec stamp_xtime; /* xtime as at tb_orig_stamp */
+ __s64 stamp_xtime_sec; /* xtime secs as at tb_orig_stamp */
+ __s64 stamp_xtime_nsec; /* xtime nsecs as at tb_orig_stamp */
__u32 syscall_map_64[SYSCALL_MAP_SIZE]; /* map of syscalls */
__u32 syscall_map_32[SYSCALL_MAP_SIZE]; /* map of syscalls */
};
@@ -101,7 +102,8 @@ struct vdso_data {
__u32 tz_dsttime; /* Type of dst correction 0x5C */
__s32 wtom_clock_sec; /* Wall to monotonic clock */
__s32 wtom_clock_nsec;
- struct timespec stamp_xtime; /* xtime as at tb_orig_stamp */
+ __s32 stamp_xtime_sec; /* xtime seconds as at tb_orig_stamp */
+ __s32 stamp_xtime_nsec; /* xtime nsecs as at tb_orig_stamp */
__u32 stamp_sec_fraction; /* fractional seconds of stamp_xtime */
__u32 syscall_map_32[SYSCALL_MAP_SIZE]; /* map of syscalls */
__u32 dcache_block_size; /* L1 d-cache block size */
diff --git a/arch/powerpc/kernel/asm-offsets.c b/arch/powerpc/kernel/asm-offsets.c
index 827f4c354e13..f22bd6d1fe93 100644
--- a/arch/powerpc/kernel/asm-offsets.c
+++ b/arch/powerpc/kernel/asm-offsets.c
@@ -385,7 +385,8 @@ int main(void)
OFFSET(CFG_SYSCALL_MAP32, vdso_data, syscall_map_32);
OFFSET(WTOM_CLOCK_SEC, vdso_data, wtom_clock_sec);
OFFSET(WTOM_CLOCK_NSEC, vdso_data, wtom_clock_nsec);
- OFFSET(STAMP_XTIME, vdso_data, stamp_xtime);
+ OFFSET(STAMP_XTIME_SEC, vdso_data, stamp_xtime_sec);
+ OFFSET(STAMP_XTIME_NSEC, vdso_data, stamp_xtime_nsec);
OFFSET(STAMP_SEC_FRAC, vdso_data, stamp_sec_fraction);
OFFSET(CFG_ICACHE_BLOCKSZ, vdso_data, icache_block_size);
OFFSET(CFG_DCACHE_BLOCKSZ, vdso_data, dcache_block_size);
@@ -395,18 +396,13 @@ int main(void)
OFFSET(CFG_SYSCALL_MAP64, vdso_data, syscall_map_64);
OFFSET(TVAL64_TV_SEC, __kernel_old_timeval, tv_sec);
OFFSET(TVAL64_TV_USEC, __kernel_old_timeval, tv_usec);
+#endif
+ OFFSET(TSPC64_TV_SEC, __kernel_timespec, tv_sec);
+ OFFSET(TSPC64_TV_NSEC, __kernel_timespec, tv_nsec);
OFFSET(TVAL32_TV_SEC, old_timeval32, tv_sec);
OFFSET(TVAL32_TV_USEC, old_timeval32, tv_usec);
- OFFSET(TSPC64_TV_SEC, timespec, tv_sec);
- OFFSET(TSPC64_TV_NSEC, timespec, tv_nsec);
OFFSET(TSPC32_TV_SEC, old_timespec32, tv_sec);
OFFSET(TSPC32_TV_NSEC, old_timespec32, tv_nsec);
-#else
- OFFSET(TVAL32_TV_SEC, __kernel_old_timeval, tv_sec);
- OFFSET(TVAL32_TV_USEC, __kernel_old_timeval, tv_usec);
- OFFSET(TSPC32_TV_SEC, timespec, tv_sec);
- OFFSET(TSPC32_TV_NSEC, timespec, tv_nsec);
-#endif
/* timeval/timezone offsets for use by vdso */
OFFSET(TZONE_TZ_MINWEST, timezone, tz_minuteswest);
OFFSET(TZONE_TZ_DSTTIME, timezone, tz_dsttime);
diff --git a/arch/powerpc/kernel/time.c b/arch/powerpc/kernel/time.c
index 694522308cd5..1fad5a04d083 100644
--- a/arch/powerpc/kernel/time.c
+++ b/arch/powerpc/kernel/time.c
@@ -885,7 +885,7 @@ static notrace u64 timebase_read(struct clocksource *cs)

void update_vsyscall(struct timekeeper *tk)
{
- struct timespec xt;
+ struct timespec64 xt;
struct clocksource *clock = tk->tkr_mono.clock;
u32 mult = tk->tkr_mono.mult;
u32 shift = tk->tkr_mono.shift;
@@ -957,7 +957,8 @@ void update_vsyscall(struct timekeeper *tk)
vdso_data->tb_to_xs = new_tb_to_xs;
vdso_data->wtom_clock_sec = tk->wall_to_monotonic.tv_sec;
vdso_data->wtom_clock_nsec = tk->wall_to_monotonic.tv_nsec;
- vdso_data->stamp_xtime = xt;
+ vdso_data->stamp_xtime_sec = xt.sec;
+ vdso_data->stamp_xtime_nsec = xt.nsec;
vdso_data->stamp_sec_fraction = frac_sec;
smp_wmb();
++(vdso_data->tb_update_count);
diff --git a/arch/powerpc/kernel/vdso32/gettimeofday.S b/arch/powerpc/kernel/vdso32/gettimeofday.S
index 4327665ad86f..37ba4c3d965b 100644
--- a/arch/powerpc/kernel/vdso32/gettimeofday.S
+++ b/arch/powerpc/kernel/vdso32/gettimeofday.S
@@ -15,10 +15,8 @@
/* Offset for the low 32-bit part of a field of long type */
#if defined(CONFIG_PPC64) && defined(CONFIG_CPU_BIG_ENDIAN)
#define LOPART 4
-#define TSPEC_TV_SEC TSPC64_TV_SEC+LOPART
#else
#define LOPART 0
-#define TSPEC_TV_SEC TSPC32_TV_SEC
#endif

.text
@@ -192,7 +190,7 @@ V_FUNCTION_BEGIN(__kernel_time)
bl __get_datapage@local
mr r9, r3 /* datapage ptr in r9 */

- lwz r3,STAMP_XTIME+TSPEC_TV_SEC(r9)
+ lwz r3,STAMP_XTIME_SEC+LOWPART(r9)

cmplwi r11,0 /* check if t is NULL */
beq 2f
@@ -268,7 +266,7 @@ __do_get_tspec:
* as a 32.32 fixed-point number in r3 and r4.
* Load & add the xtime stamp.
*/
- lwz r5,STAMP_XTIME+TSPEC_TV_SEC(r9)
+ lwz r5,STAMP_XTIME_SEC+LOWPART(r9)
lwz r6,STAMP_SEC_FRAC(r9)
addc r4,r4,r6
adde r3,r3,r5
diff --git a/arch/powerpc/kernel/vdso64/gettimeofday.S b/arch/powerpc/kernel/vdso64/gettimeofday.S
index 07bfe33fe874..1f24e411af80 100644
--- a/arch/powerpc/kernel/vdso64/gettimeofday.S
+++ b/arch/powerpc/kernel/vdso64/gettimeofday.S
@@ -116,8 +116,8 @@ V_FUNCTION_BEGIN(__kernel_clock_gettime)
* CLOCK_REALTIME_COARSE, below values are needed for MONOTONIC_COARSE
* too
*/
- ld r4,STAMP_XTIME+TSPC64_TV_SEC(r3)
- ld r5,STAMP_XTIME+TSPC64_TV_NSEC(r3)
+ ld r4,STAMP_XTIME_SEC(r3)
+ ld r5,STAMP_XTIME_NSEC(r3)
bne cr6,75f

/* CLOCK_MONOTONIC_COARSE */
@@ -220,7 +220,7 @@ V_FUNCTION_BEGIN(__kernel_time)
mr r11,r3 /* r11 holds t */
bl V_LOCAL_FUNC(__get_datapage)

- ld r4,STAMP_XTIME+TSPC64_TV_SEC(r3)
+ ld r4,STAMP_XTIME_SEC(r3)

cmpldi r11,0 /* check if t is NULL */
beq 2f
@@ -265,7 +265,7 @@ V_FUNCTION_BEGIN(__do_get_tspec)
mulhdu r6,r6,r5 /* in units of 2^-32 seconds */

/* Add stamp since epoch */
- ld r4,STAMP_XTIME+TSPC64_TV_SEC(r3)
+ ld r4,STAMP_XTIME_SEC(r3)
lwz r5,STAMP_SEC_FRAC(r3)
or r0,r4,r5
or r0,r0,r6
--
2.20.0

Next message: Jeffrey Hugo: "[PATCH v7 1/6] dt-bindings: clock: Document external clocks for MSM8998 gcc"
Previous message: Arnd Bergmann: "[PATCH 05/23] y2038: vdso: change time_t to __kernel_old_time_t"
In reply to: Thomas Gleixner: "Re: [PATCH 05/23] y2038: vdso: change time_t to __kernel_old_time_t"
Next in thread: Arnd Bergmann: "[PATCH 09/23] y2038: stat: avoid 'time_t' in 'struct stat'"
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