From 1e3f17f55aec6510f88ff65dcbaae13435af0ba6 Mon Sep 17 00:00:00 2001 From: Vincenzo Frascino Date: Fri, 21 Jun 2019 10:52:40 +0100 Subject: [PATCH] arm64: elf: VDSO code page discovery Like in normal vDSOs, when compat vDSOs are enabled the auxiliary vector symbol AT_SYSINFO_EHDR needs to point to the address of the vDSO code, to allow the dynamic linker to find it. Add the necessary code to the elf arm64 module to make this possible. Signed-off-by: Vincenzo Frascino Signed-off-by: Thomas Gleixner Tested-by: Shijith Thotton Tested-by: Andre Przywara Cc: linux-arch@vger.kernel.org Cc: linux-arm-kernel@lists.infradead.org Cc: linux-mips@vger.kernel.org Cc: linux-kselftest@vger.kernel.org Cc: Catalin Marinas Cc: Will Deacon Cc: Arnd Bergmann Cc: Russell King Cc: Ralf Baechle Cc: Paul Burton Cc: Daniel Lezcano Cc: Mark Salyzyn Cc: Peter Collingbourne Cc: Shuah Khan Cc: Dmitry Safonov <0x7f454c46@gmail.com> Cc: Rasmus Villemoes Cc: Huw Davies Link: https://lkml.kernel.org/r/20190621095252.32307-14-vincenzo.frascino@arm.com --- arch/arm64/include/asm/elf.h | 14 ++++++++++++++ 1 file changed, 14 insertions(+) diff --git a/arch/arm64/include/asm/elf.h b/arch/arm64/include/asm/elf.h index 325d9515c0f8..3c7037c6ba9b 100644 --- a/arch/arm64/include/asm/elf.h +++ b/arch/arm64/include/asm/elf.h @@ -202,7 +202,21 @@ typedef compat_elf_greg_t compat_elf_gregset_t[COMPAT_ELF_NGREG]; ({ \ set_thread_flag(TIF_32BIT); \ }) +#ifdef CONFIG_GENERIC_COMPAT_VDSO +#define COMPAT_ARCH_DLINFO \ +do { \ + /* \ + * Note that we use Elf64_Off instead of elf_addr_t because \ + * elf_addr_t in compat is defined as Elf32_Addr and casting \ + * current->mm->context.vdso to it triggers a cast warning of \ + * cast from pointer to integer of different size. \ + */ \ + NEW_AUX_ENT(AT_SYSINFO_EHDR, \ + (Elf64_Off)current->mm->context.vdso); \ +} while (0) +#else #define COMPAT_ARCH_DLINFO +#endif extern int aarch32_setup_additional_pages(struct linux_binprm *bprm, int uses_interp); #define compat_arch_setup_additional_pages \ -- 2.30.2