[PATCH 24/25] arm64:ilp32: add vdso-ilp32 and use for signal return

Zhangjian (Bamvor)
2016-05-09T10:07:06Z

Hi, yury

I tested successful in both little endian and big endian.
Just two comments below:

On 2016/5/6 22:00, Yury Norov wrote:
> Hello colleagues,
>
> After all comments, VDSO fix looks like this for me.
>
> Note I renamed Andrew's ZERO macro to DELOUSE, as
> there already is __SC_DELOUSE which does the same,
> but in C, not asm.
>
> Like Bamvor, I'm not sure how we'd apply this patch -
> standalone or meld to VDSO. I think, VDSO patch is too
> big and bad-structurized, and if I find how to refactor
> it, I'll incorporate this fix.
>
> Signed-off-by: Yury Norov <ynorov@caviumnetworks.com>
> ---
> arch/arm64/kernel/asm-offsets.c | 7 +++++++
> arch/arm64/kernel/vdso-ilp32/vdso-ilp32.lds.S | 2 +-
> arch/arm64/kernel/vdso/gettimeofday.S | 20 +++++++++++++++++---
> 3 files changed, 25 insertions(+), 4 deletions(-)
>
> diff --git a/arch/arm64/kernel/asm-offsets.c b/arch/arm64/kernel/asm-offsets.c
> index e229525..fcfd087 100644
> --- a/arch/arm64/kernel/asm-offsets.c
> +++ b/arch/arm64/kernel/asm-offsets.c
> @@ -101,6 +101,13 @@ int main(void)
> DEFINE(TSPEC_TV_SEC, offsetof(struct timespec, tv_sec));
> DEFINE(TSPEC_TV_NSEC, offsetof(struct timespec, tv_nsec));
> BLANK();
> +#ifdef CONFIG_ARM64_ILP32
The following structs exist in both aarch32 el0 and ilp32. How about change it to
"#ifdef CONFIG_COMPAT"?
> + DEFINE(COMPAT_TVAL_TV_SEC, offsetof(struct compat_timeval, tv_sec));
> + DEFINE(COMPAT_TVAL_TV_USEC, offsetof(struct compat_timeval, tv_usec));
> + DEFINE(COMPAT_TSPEC_TV_SEC, offsetof(struct compat_timespec, tv_sec));
> + DEFINE(COMPAT_TSPEC_TV_NSEC, offsetof(struct compat_timespec, tv_nsec));
> + BLANK();
> +#endif
> DEFINE(TZ_MINWEST, offsetof(struct timezone, tz_minuteswest));
> DEFINE(TZ_DSTTIME, offsetof(struct timezone, tz_dsttime));
> BLANK();
> diff --git a/arch/arm64/kernel/vdso-ilp32/vdso-ilp32.lds.S b/arch/arm64/kernel/vdso-ilp32/vdso-ilp32.lds.S
> index ddc63fd..d182a8d 100644
> --- a/arch/arm64/kernel/vdso-ilp32/vdso-ilp32.lds.S
> +++ b/arch/arm64/kernel/vdso-ilp32/vdso-ilp32.lds.S
> @@ -79,7 +79,7 @@ PHDRS
> */
> VERSION
> {
> - LINUX_2.6 {
> + LINUX_2.6.39 {
Do we really want to this version? Maybe 4.x is better?

Regards

Bamvor

> global:
> __kernel_rt_sigreturn;
> __kernel_gettimeofday;
> diff --git a/arch/arm64/kernel/vdso/gettimeofday.S b/arch/arm64/kernel/vdso/gettimeofday.S
> index efa79e8..a2d8a70 100644
> --- a/arch/arm64/kernel/vdso/gettimeofday.S
> +++ b/arch/arm64/kernel/vdso/gettimeofday.S
> @@ -25,6 +25,16 @@
> #define NSEC_PER_SEC_LO16 0xca00
> #define NSEC_PER_SEC_HI16 0x3b9a
>
> +#ifdef __LP64__
> +#define PTR_REG(n) x##n
> +#define OFFSET(n) n
> +#define DELOUSE(n)
> +#else
> +#define PTR_REG(n) w##n
> +#define OFFSET(n) COMPAT_##n
> +#define DELOUSE(n) mov w##n, w##n
> +#endif
> +
> vdso_data .req x6
> use_syscall .req w7
> seqcnt .req w8
> @@ -51,6 +61,8 @@ seqcnt .req w8
> /* int __kernel_gettimeofday(struct timeval *tv, struct timezone *tz); */
> ENTRY(__kernel_gettimeofday)
> .cfi_startproc
> + DELOUSE(0)
> + DELOUSE(1)
> mov x2, x30
> .cfi_register x30, x2
>
> @@ -68,7 +80,7 @@ ENTRY(__kernel_gettimeofday)
> mov x13, #1000
> lsl x13, x13, x12
> udiv x11, x11, x13
> - stp x10, x11, [x0, #TVAL_TV_SEC]
> + stp PTR_REG(10), PTR_REG(11), [x0, #OFFSET(TVAL_TV_SEC)]
> 2:
> /* If tz is NULL, return 0. */
> cbz x1, 3f
> @@ -88,6 +100,7 @@ ENDPROC(__kernel_gettimeofday)
> /* int __kernel_clock_gettime(clockid_t clock_id, struct timespec *tp); */
> ENTRY(__kernel_clock_gettime)
> .cfi_startproc
> + DELOUSE(1)
> cmp w0, #CLOCK_REALTIME
> ccmp w0, #CLOCK_MONOTONIC, #0x4, ne
> b.ne 2f
> @@ -159,7 +172,7 @@ ENTRY(__kernel_clock_gettime)
>
> 6: /* Store to the user timespec. */
> lsr x11, x11, x12
> - stp x10, x11, [x1, #TSPEC_TV_SEC]
> + stp PTR_REG(10), PTR_REG(11), [x1, #OFFSET(TSPEC_TV_SEC)]
> mov x0, xzr
> ret
> 7:
> @@ -174,6 +187,7 @@ ENDPROC(__kernel_clock_gettime)
> /* int __kernel_clock_getres(clockid_t clock_id, struct timespec *res); */
> ENTRY(__kernel_clock_getres)
> .cfi_startproc
> + DELOUSE(1)
> cmp w0, #CLOCK_REALTIME
> ccmp w0, #CLOCK_MONOTONIC, #0x4, ne
> b.ne 1f
> @@ -187,7 +201,7 @@ ENTRY(__kernel_clock_getres)
> ldr x2, 6f
> 2:
> cbz w1, 3f
> - stp xzr, x2, [x1]
> + stp PTR_REG(zr), PTR_REG(2), [x1]
>
> 3: /* res == NULL. */
> mov w0, wzr
>