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| author | Vincenzo Frascino <vincenzo.frascino@arm.com> | 2019-04-16 18:14:30 +0200 |
|---|---|---|
| committer | Will Deacon <will.deacon@arm.com> | 2019-04-16 19:15:56 +0200 |
| commit | 81fb8736dd81da3fe94f28968dac60f392ec6746 (patch) | |
| tree | 10b8e1dc7cfa6a70d87a9dc72cf6bc724fe5c05e /arch/arm64/kernel/vdso/gettimeofday.S | |
| parent | arm64: Use the correct style for SPDX License Identifier (diff) | |
| download | linux-81fb8736dd81da3fe94f28968dac60f392ec6746.tar.xz linux-81fb8736dd81da3fe94f28968dac60f392ec6746.zip | |
arm64: vdso: Fix clock_getres() for CLOCK_REALTIME
clock_getres() in the vDSO library has to preserve the same behaviour
of posix_get_hrtimer_res().
In particular, posix_get_hrtimer_res() does:
sec = 0;
ns = hrtimer_resolution;
where 'hrtimer_resolution' depends on whether or not high resolution
timers are enabled, which is a runtime decision.
The vDSO incorrectly returns the constant CLOCK_REALTIME_RES. Fix this
by exposing 'hrtimer_resolution' in the vDSO datapage and returning that
instead.
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
[will: Use WRITE_ONCE(), move adr off COARSE path, renumber labels, use 'w' reg]
Signed-off-by: Will Deacon <will.deacon@arm.com>
Diffstat (limited to 'arch/arm64/kernel/vdso/gettimeofday.S')
| -rw-r--r-- | arch/arm64/kernel/vdso/gettimeofday.S | 7 |
1 files changed, 3 insertions, 4 deletions
diff --git a/arch/arm64/kernel/vdso/gettimeofday.S b/arch/arm64/kernel/vdso/gettimeofday.S index c39872a7b03c..21805e416483 100644 --- a/arch/arm64/kernel/vdso/gettimeofday.S +++ b/arch/arm64/kernel/vdso/gettimeofday.S @@ -301,13 +301,14 @@ ENTRY(__kernel_clock_getres) ccmp w0, #CLOCK_MONOTONIC_RAW, #0x4, ne b.ne 1f - ldr x2, 5f + adr vdso_data, _vdso_data + ldr w2, [vdso_data, #CLOCK_REALTIME_RES] b 2f 1: cmp w0, #CLOCK_REALTIME_COARSE ccmp w0, #CLOCK_MONOTONIC_COARSE, #0x4, ne b.ne 4f - ldr x2, 6f + ldr x2, 5f 2: cbz x1, 3f stp xzr, x2, [x1] @@ -321,8 +322,6 @@ ENTRY(__kernel_clock_getres) svc #0 ret 5: - .quad CLOCK_REALTIME_RES -6: .quad CLOCK_COARSE_RES .cfi_endproc ENDPROC(__kernel_clock_getres) |