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y2038: vdso: powerpc: avoid timespec references 

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@arndb.de>
This commit is contained in:
Arnd Bergmann 2019-10-27 17:26:55 +01:00
parent e6071b182d
commit 176ed98c8a
5 changed files with 18 additions and 21 deletions
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6
arch/powerpc/include/asm/vdso_datapage.h
View File

@ -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 */

14
arch/powerpc/kernel/asm-offsets.c
View File

@ -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);

5
arch/powerpc/kernel/time.c
View File

@ -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.tv_sec;
vdso_data->stamp_xtime_nsec = xt.tv_nsec;
vdso_data->stamp_sec_fraction = frac_sec;
smp_wmb();
++(vdso_data->tb_update_count);

6
arch/powerpc/kernel/vdso32/gettimeofday.S
View File

@ -15,10 +15,8 @@
/* Offset for the low 32-bit part of a field of long type */
#ifdef CONFIG_PPC64
#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

8
arch/powerpc/kernel/vdso64/gettimeofday.S
View File

@ -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