From: Alex Bee <knaerzche@gmail.com> To: Robin Murphy <robin.murphy@arm.com>, linux-arch@vger.kernel.org Cc: Florian Fainelli <f.fainelli@gmail.com>, Daniel Jordan <daniel.m.jordan@oracle.com>, linux-arm-kernel@lists.infradead.org, Russell King <linux@armlinux.org.uk>, Vincenzo Frascino <vincenzo.frascino@arm.com>, Vlastimil Babka <vbabka@suse.cz> Subject: Re: [PATCH] linux: arm: vdso: nullpatch vdso_clock_gettime64 for non-virtual timers Date: Fri, 17 Jul 2020 01:25:53 +0200 [thread overview] Message-ID: <2c4484bf-a127-6f07-75f2-e0f0a15fe257@gmail.com> (raw) In-Reply-To: <ac44a5a3-ca35-cd0a-f823-4b814c01c498@arm.com> 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
WARNING: multiple messages have this Message-ID (diff)
From: Alex Bee <knaerzche@gmail.com> To: Robin Murphy <robin.murphy@arm.com>, linux-arch@vger.kernel.org Cc: Florian Fainelli <f.fainelli@gmail.com>, Russell King <linux@armlinux.org.uk>, Daniel Jordan <daniel.m.jordan@oracle.com>, linux-arm-kernel@lists.infradead.org, Vincenzo Frascino <vincenzo.frascino@arm.com>, Vlastimil Babka <vbabka@suse.cz> Subject: Re: [PATCH] linux: arm: vdso: nullpatch vdso_clock_gettime64 for non-virtual timers Date: Fri, 17 Jul 2020 01:25:53 +0200 [thread overview] Message-ID: <2c4484bf-a127-6f07-75f2-e0f0a15fe257@gmail.com> (raw) In-Reply-To: <ac44a5a3-ca35-cd0a-f823-4b814c01c498@arm.com> 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 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
next prev parent reply other threads:[~2020-07-16 23:25 UTC|newest] Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top 2020-07-16 15:07 [PATCH] linux: arm: vdso: nullpatch vdso_clock_gettime64 for non-virtual timers Alex Bee 2020-07-16 15:07 ` Alex Bee 2020-07-16 18:46 ` Robin Murphy 2020-07-16 18:46 ` Robin Murphy 2020-07-16 23:25 ` Alex Bee [this message] 2020-07-16 23:25 ` Alex Bee
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