| Message ID | 20200716150723.9389-1-knaerzche@gmail.com (mailing list archive) |
|---|---|
| State | Mainlined |
| Commit | 4405bdf3c57ec28d606bdf5325f1167505bfdcd4 |
| Headers | show |
| Series | linux: arm: vdso: nullpatch vdso_clock_gettime64 for non-virtual timers | expand |
Hi Alex, On 2020-07-16 16:07, Alex Bee wrote: > Along with commit commit 74d06efb9c2f ("ARM: 8932/1: Add clock_gettime64 > entry point") clock_gettime64 was added for ARM platform to solve the > y2k38 problem on 32-bit platforms. glibc from version 2.31 onwards > started using this vdso-call on ARM platforms. > However it was (probably) forgotten to "nullpatch" this call, when no > reliable timer source is available, for example when > "arm,cpu-registers-not-fw-configured" is defined in devicetree for > "arm,armv7-timer". > This results in erratic time jumps whenever "gettimeofday" gets called, > since the (non-working) vdso-call will be used instead of a syscall. > > This patch adds clock_gettime64 to get nullpatched as well. It has been > verified to work and solve this issue on Rockchip RK322x, RK3288 and > RPi4 (32-bit kernel build) platforms. FYI, a version of this patch was already submitted, and is just waiting for Russell to apply it: https://www.armlinux.org.uk/developer/patches/viewpatch.php?id=8987/1 Robin. > Signed-off-by: Alex Bee <knaerzche@gmail.com> > --- > arch/arm/kernel/vdso.c | 1 + > 1 file changed, 1 insertion(+) > > diff --git a/arch/arm/kernel/vdso.c b/arch/arm/kernel/vdso.c > index 6bfdca4769a7..fddd08a6e063 100644 > --- a/arch/arm/kernel/vdso.c > +++ b/arch/arm/kernel/vdso.c > @@ -184,6 +184,7 @@ static void __init patch_vdso(void *ehdr) > if (!cntvct_ok) { > vdso_nullpatch_one(&einfo, "__vdso_gettimeofday"); > vdso_nullpatch_one(&einfo, "__vdso_clock_gettime"); > + vdso_nullpatch_one(&einfo, "__vdso_clock_gettime64"); > } > } > >
Hi Robin, Am 16.07.20 um 20:46 schrieb Robin Murphy: > Hi Alex, > > On 2020-07-16 16:07, Alex Bee wrote: >> Along with commit commit 74d06efb9c2f ("ARM: 8932/1: Add clock_gettime64 >> entry point") clock_gettime64 was added for ARM platform to solve the >> y2k38 problem on 32-bit platforms. glibc from version 2.31 onwards >> started using this vdso-call on ARM platforms. >> However it was (probably) forgotten to "nullpatch" this call, when no >> reliable timer source is available, for example when >> "arm,cpu-registers-not-fw-configured" is defined in devicetree for >> "arm,armv7-timer". >> This results in erratic time jumps whenever "gettimeofday" gets called, >> since the (non-working) vdso-call will be used instead of a syscall. >> >> This patch adds clock_gettime64 to get nullpatched as well. It has been >> verified to work and solve this issue on Rockchip RK322x, RK3288 and >> RPi4 (32-bit kernel build) platforms. > > FYI, a version of this patch was already submitted, and is just > waiting for Russell to apply it: > > https://www.armlinux.org.uk/developer/patches/viewpatch.php?id=8987/1 > > Robin. OK - couldn't find this before. You can drop my patch than. > >> Signed-off-by: Alex Bee <knaerzche@gmail.com> >> --- >> arch/arm/kernel/vdso.c | 1 + >> 1 file changed, 1 insertion(+) >> >> diff --git a/arch/arm/kernel/vdso.c b/arch/arm/kernel/vdso.c >> index 6bfdca4769a7..fddd08a6e063 100644 >> --- a/arch/arm/kernel/vdso.c >> +++ b/arch/arm/kernel/vdso.c >> @@ -184,6 +184,7 @@ static void __init patch_vdso(void *ehdr) >> if (!cntvct_ok) { >> vdso_nullpatch_one(&einfo, "__vdso_gettimeofday"); >> vdso_nullpatch_one(&einfo, "__vdso_clock_gettime"); >> + vdso_nullpatch_one(&einfo, "__vdso_clock_gettime64"); >> } >> } >> Regards, Alex
diff --git a/arch/arm/kernel/vdso.c b/arch/arm/kernel/vdso.c index 6bfdca4769a7..fddd08a6e063 100644 --- a/arch/arm/kernel/vdso.c +++ b/arch/arm/kernel/vdso.c @@ -184,6 +184,7 @@ static void __init patch_vdso(void *ehdr) if (!cntvct_ok) { vdso_nullpatch_one(&einfo, "__vdso_gettimeofday"); vdso_nullpatch_one(&einfo, "__vdso_clock_gettime"); + vdso_nullpatch_one(&einfo, "__vdso_clock_gettime64"); } }
Along with commit commit 74d06efb9c2f ("ARM: 8932/1: Add clock_gettime64 entry point") clock_gettime64 was added for ARM platform to solve the y2k38 problem on 32-bit platforms. glibc from version 2.31 onwards started using this vdso-call on ARM platforms. However it was (probably) forgotten to "nullpatch" this call, when no reliable timer source is available, for example when "arm,cpu-registers-not-fw-configured" is defined in devicetree for "arm,armv7-timer". This results in erratic time jumps whenever "gettimeofday" gets called, since the (non-working) vdso-call will be used instead of a syscall. This patch adds clock_gettime64 to get nullpatched as well. It has been verified to work and solve this issue on Rockchip RK322x, RK3288 and RPi4 (32-bit kernel build) platforms. Signed-off-by: Alex Bee <knaerzche@gmail.com> --- arch/arm/kernel/vdso.c | 1 + 1 file changed, 1 insertion(+)