From: Vincenzo Frascino Date: Wed, 10 Jul 2019 14:01:19 +0000 (+0100) Subject: arm64: vdso: Fix population of AT_SYSINFO_EHDR for compat vdso X-Git-Tag: v5.3-rc2~22^2~15 X-Git-Url: https://asedeno.scripts.mit.edu/gitweb/?a=commitdiff_plain;h=85751e9e5b1480fc675106aeaf94fadb8028469b;p=linux.git arm64: vdso: Fix population of AT_SYSINFO_EHDR for compat vdso Prior to the introduction of Unified vDSO support and compat layer for vDSO on arm64, AT_SYSINFO_EHDR was not defined for compat tasks. In the current implementation, AT_SYSINFO_EHDR is defined even if the compat vdso layer is not built, which has been shown to break Android applications using bionic: | 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) Restore the old behaviour by making sure that AT_SYSINFO_EHDR for compat tasks is defined only when CONFIG_COMPAT_VDSO is enabled. Reported-by: John Stultz Tested-by: John Stultz Signed-off-by: Vincenzo Frascino Signed-off-by: Will Deacon --- diff --git a/arch/arm64/include/asm/elf.h b/arch/arm64/include/asm/elf.h index 3c7037c6ba9b..b618017205a3 100644 --- a/arch/arm64/include/asm/elf.h +++ b/arch/arm64/include/asm/elf.h @@ -202,7 +202,7 @@ typedef compat_elf_greg_t compat_elf_gregset_t[COMPAT_ELF_NGREG]; ({ \ set_thread_flag(TIF_32BIT); \ }) -#ifdef CONFIG_GENERIC_COMPAT_VDSO +#ifdef CONFIG_COMPAT_VDSO #define COMPAT_ARCH_DLINFO \ do { \ /* \