Hi John, On 10/07/2019 05:02, John Stultz wrote: > On Fri, Jun 21, 2019 at 3:18 AM Vincenzo Frascino > <vincenzo.frascino@xxxxxxx> wrote: >> >> Provide the arm64 compat (AArch32) vDSO in kernel/vdso32 in a similar >> way to what happens in kernel/vdso. >> >> The compat vDSO leverages on an adaptation of the arm architecture code >> with few changes: >> - Use of lib/vdso for gettimeofday >> - Implementation of syscall based fallback >> - Introduction of clock_getres for the compat library >> - Implementation of trampolines >> - Implementation of elf note >> >> To build the compat vDSO a 32 bit compiler is required and needs to be >> specified via CONFIG_CROSS_COMPILE_COMPAT_VDSO. >> > > Hey Vincenzo! > Congrats on getting this work merged, I know its been a long effort > over a number of years! > > Though unfortunately, it seems the arm64 vdso code that just landed is > breaking AOSP for me. > > I see a lot of the following errors: > 01-01 01:22:14.097 755 755 F libc : Fatal signal 11 (SIGSEGV), > code 1 (SEGV_MAPERR), fault addr 0x3cf2c96c in tid 755 (cameraserver), > pid 755 (cameraserver) > 01-01 01:22:14.112 759 759 F libc : Fatal signal 11 (SIGSEGV), > code 1 (SEGV_MAPERR), fault addr 0x3cf2c96c in tid 759 > (android.hardwar), pid 759 (android.hardwar) > 01-01 01:22:14.120 756 756 F libc : Fatal signal 11 (SIGSEGV), > code 1 (SEGV_MAPERR), fault addr 0x3cf2c96c in tid 756 (drmserver), > pid 756 (drmserver) > > Which go away if I revert the vdso merge that went in via tip/timers. > > I tried to bisect things down a bit, but as some later fixes are > required (at one point, date was returning the start epoch and never > increasing), this hasn't worked too well. But I'm guessing since I > see: "CROSS_COMPILE_COMPAT not defined or empty, the compat vDSO will > not be built", and the system is half working, I'm guessing this is an > issue with just the 32bit code failing. While I can try to sort out > the proper CROSS_COMPILE_COMPAT in my build environment, I assume > userland shouldn't be crashing if that value isn't set. > > Any chance this issue has already been raised? > I do not have Android (bionic/libc) as part of my testing environment hence I never saw this issue. Thanks for reporting it. I am investigating the problem and will post a fix as soon as it is ready. As Will suggested, .config would help the debugging and I would like to ask to you to test my fix once it is ready. Is that OK for you? > thanks > -john > -- Regards, Vincenzo
