@@ -103,6 +103,8 @@ ENTRY(__kernel_clock_gettime)
bl __do_get_tspec
seqcnt_check w9, 1b
+ mov x30, x2
+
cmp w0, #CLOCK_MONOTONIC
b.ne 6f
@@ -118,6 +120,9 @@ ENTRY(__kernel_clock_gettime)
ccmp w0, #CLOCK_MONOTONIC_COARSE, #0x4, ne
b.ne 8f
+ /* xtime_coarse_nsec is already right-shifted */
+ mov x12, #0
+
/* Get coarse timespec. */
adr vdso_data, _vdso_data
3: seqcnt_acquire
@@ -156,7 +161,7 @@ ENTRY(__kernel_clock_gettime)
lsr x11, x11, x12
stp x10, x11, [x1, #TSPEC_TV_SEC]
mov x0, xzr
- ret x2
+ ret
7:
mov x30, x2
8: /* Syscall fallback. */
This is a note to let you know that I have just added a patch titled arm64: vdso: fix coarse clock handling to the linux-3.11.y-queue branch of the 3.11.y.z extended stable tree which can be found at: http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.11.y-queue If you, or anyone else, feels it should not be added to this tree, please reply to this email. For more information about the 3.11.y.z tree, see https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable Thanks. -Luis ------ From eb64bc22c45ab606eab0b033ce5879f56c635f2a Mon Sep 17 00:00:00 2001 From: Nathan Lynch <nathan_lynch@mentor.com> Date: Wed, 5 Feb 2014 05:53:04 +0000 Subject: arm64: vdso: fix coarse clock handling commit 069b918623e1510e58dacf178905a72c3baa3ae4 upstream. When __kernel_clock_gettime is called with a CLOCK_MONOTONIC_COARSE or CLOCK_REALTIME_COARSE clock id, it returns incorrectly to whatever the caller has placed in x2 ("ret x2" to return from the fast path). Fix this by saving x30/LR to x2 only in code that will call __do_get_tspec, restoring x30 afterward, and using a plain "ret" to return from the routine. Also: while the resulting tv_nsec value for CLOCK_REALTIME and CLOCK_MONOTONIC must be computed using intermediate values that are left-shifted by cs_shift (x12, set by __do_get_tspec), the results for coarse clocks should be calculated using unshifted values (xtime_coarse_nsec is in units of actual nanoseconds). The current code shifts intermediate values by x12 unconditionally, but x12 is uninitialized when servicing a coarse clock. Fix this by setting x12 to 0 once we know we are dealing with a coarse clock id. Signed-off-by: Nathan Lynch <nathan_lynch@mentor.com> Acked-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Luis Henriques <luis.henriques@canonical.com> --- arch/arm64/kernel/vdso/gettimeofday.S | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) -- 1.8.3.2