From: Thomas Gleixner <tglx@linutronix.de>
To: LKML <linux-kernel@vger.kernel.org>
Cc: x86@kernel.org, Andy Lutomirski <luto@kernel.org>,
Vincenzo Frascino <vincenzo.frascino@arm.com>,
Sean Christopherson <sean.j.christopherson@intel.com>,
Kees Cook <keescook@chromium.org>,
Paul Bolle <pebolle@tiscali.nl>, Will Deacon <will@kernel.org>
Subject: [patch 2/5] lib/vdso: Move fallback invocation to the callers
Date: Sun, 28 Jul 2019 15:12:53 +0200 [thread overview]
Message-ID: <20190728131648.695579736@linutronix.de> (raw)
In-Reply-To: 20190728131251.622415456@linutronix.de
To allow syscall fallbacks using the legacy 32bit syscall for 32bit VDSO
builds, move the fallback invocation out into the callers.
Split the common code out of __cvdso_clock_gettime/getres() and invoke the
syscall fallback in the 64bit and 32bit variants.
Preparatory work for using legacy syscalls in 32bit VDSO. No functional
change.
Fixes: 00b26474c2f1 ("lib/vdso: Provide generic VDSO implementation")
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
---
lib/vdso/gettimeofday.c | 53 ++++++++++++++++++++++++++++++++----------------
1 file changed, 36 insertions(+), 17 deletions(-)
--- a/lib/vdso/gettimeofday.c
+++ b/lib/vdso/gettimeofday.c
@@ -51,7 +51,7 @@ static int do_hres(const struct vdso_dat
ns = vdso_ts->nsec;
last = vd->cycle_last;
if (unlikely((s64)cycles < 0))
- return clock_gettime_fallback(clk, ts);
+ return -1;
ns += vdso_calc_delta(cycles, last, vd->mask, vd->mult);
ns >>= vd->shift;
@@ -82,14 +82,14 @@ static void do_coarse(const struct vdso_
}
static __maybe_unused int
-__cvdso_clock_gettime(clockid_t clock, struct __kernel_timespec *ts)
+__cvdso_clock_gettime_common(clockid_t clock, struct __kernel_timespec *ts)
{
const struct vdso_data *vd = __arch_get_vdso_data();
u32 msk;
/* Check for negative values or invalid clocks */
if (unlikely((u32) clock >= MAX_CLOCKS))
- goto fallback;
+ return -1;
/*
* Convert the clockid to a bitmask and use it to check which
@@ -104,9 +104,17 @@ static __maybe_unused int
} else if (msk & VDSO_RAW) {
return do_hres(&vd[CS_RAW], clock, ts);
}
+ return -1;
+}
-fallback:
- return clock_gettime_fallback(clock, ts);
+static __maybe_unused int
+__cvdso_clock_gettime(clockid_t clock, struct __kernel_timespec *ts)
+{
+ int ret = __cvdso_clock_gettime_common(clock, ts);
+
+ if (unlikely(ret))
+ return clock_gettime_fallback(clock, ts);
+ return 0;
}
static __maybe_unused int
@@ -115,9 +123,12 @@ static __maybe_unused int
struct __kernel_timespec ts;
int ret;
- ret = __cvdso_clock_gettime(clock, &ts);
+ ret = __cvdso_clock_gettime_common(clock, &ts);
- if (ret == 0) {
+ if (unlikely(ret))
+ ret = clock_gettime_fallback(clock, &ts);
+
+ if (likely(!ret)) {
res->tv_sec = ts.tv_sec;
res->tv_nsec = ts.tv_nsec;
}
@@ -163,17 +174,18 @@ static __maybe_unused time_t __cvdso_tim
#ifdef VDSO_HAS_CLOCK_GETRES
static __maybe_unused
-int __cvdso_clock_getres(clockid_t clock, struct __kernel_timespec *res)
+int __cvdso_clock_getres_common(clockid_t clock, struct __kernel_timespec *res)
{
const struct vdso_data *vd = __arch_get_vdso_data();
- u64 ns;
+ u64 hrtimer_res;
u32 msk;
- u64 hrtimer_res = READ_ONCE(vd[CS_HRES_COARSE].hrtimer_res);
+ u64 ns;
/* Check for negative values or invalid clocks */
if (unlikely((u32) clock >= MAX_CLOCKS))
- goto fallback;
+ return -1;
+ hrtimer_res = READ_ONCE(vd[CS_HRES_COARSE].hrtimer_res);
/*
* Convert the clockid to a bitmask and use it to check which
* clocks are handled in the VDSO directly.
@@ -195,16 +207,22 @@ int __cvdso_clock_getres(clockid_t clock
*/
ns = hrtimer_res;
} else {
- goto fallback;
+ return -1;
}
res->tv_sec = 0;
res->tv_nsec = ns;
return 0;
+}
+
+int __cvdso_clock_getres(clockid_t clock, struct __kernel_timespec *res)
+{
+ int ret = __cvdso_clock_getres_common(clock, res);
-fallback:
- return clock_getres_fallback(clock, res);
+ if (unlikely(ret))
+ return clock_getres_fallback(clock, res);
+ return 0;
}
static __maybe_unused int
@@ -213,13 +231,14 @@ static __maybe_unused int
struct __kernel_timespec ts;
int ret;
- ret = __cvdso_clock_getres(clock, &ts);
+ ret = __cvdso_clock_getres_common(clock, &ts);
+ if (unlikely(ret))
+ ret = clock_getres_fallback(clock, &ts);
- if (ret == 0) {
+ if (likely(!ret)) {
res->tv_sec = ts.tv_sec;
res->tv_nsec = ts.tv_nsec;
}
-
return ret;
}
#endif /* VDSO_HAS_CLOCK_GETRES */
next prev parent reply other threads:[~2019-07-28 13:21 UTC|newest]
Thread overview: 28+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-07-28 13:12 [patch 0/5] lib/vdso, x86/vdso: Fix fallout from generic VDSO conversion Thomas Gleixner
2019-07-28 13:12 ` [patch 1/5] lib/vdso/32: Remove inconsistent NULL pointer checks Thomas Gleixner
2019-07-28 14:33 ` Andy Lutomirski
2019-07-28 14:42 ` Thomas Gleixner
2019-07-28 15:30 ` Vincenzo Frascino
2019-07-29 14:52 ` Sean Christopherson
2019-07-30 22:19 ` [tip:timers/urgent] " tip-bot for Thomas Gleixner
2019-07-28 13:12 ` Thomas Gleixner [this message]
2019-07-28 14:37 ` [patch 2/5] lib/vdso: Move fallback invocation to the callers Andy Lutomirski
2019-07-28 15:31 ` Vincenzo Frascino
2019-07-30 22:19 ` [tip:timers/urgent] " tip-bot for Thomas Gleixner
2019-07-28 13:12 ` [patch 3/5] lib/vdso/32: Provide legacy syscall fallbacks Thomas Gleixner
2019-07-28 14:39 ` Andy Lutomirski
2019-07-28 15:33 ` Vincenzo Frascino
2019-07-29 14:48 ` Sean Christopherson
2019-07-30 9:38 ` [patch V2 " Thomas Gleixner
2019-07-30 14:28 ` Sean Christopherson
2019-07-30 20:09 ` Andy Lutomirski
2019-07-30 20:14 ` Thomas Gleixner
2019-07-30 22:20 ` [tip:timers/urgent] " tip-bot for Thomas Gleixner
2019-07-28 13:12 ` [patch 4/5] x86/vdso/32: Use 32bit syscall fallback Thomas Gleixner
2019-07-28 14:50 ` Andy Lutomirski
2019-07-29 11:23 ` Vincenzo Frascino
2019-07-29 14:51 ` Sean Christopherson
2019-07-30 22:21 ` [tip:timers/urgent] " tip-bot for Thomas Gleixner
2019-07-28 13:12 ` [patch 5/5] arm64: compat: vdso: Use legacy syscalls as fallback Thomas Gleixner
2019-07-28 15:35 ` Vincenzo Frascino
2019-07-30 22:22 ` [tip:timers/urgent] " tip-bot for Thomas Gleixner
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