diff mbox series

[v7,13/25] arm64: elf: vDSO code page discovery

Message ID 20190621095252.32307-14-vincenzo.frascino@arm.com (mailing list archive)
State Not Applicable
Headers show
Series Unify vDSOs across more architectures | expand

Commit Message

Vincenzo Frascino June 21, 2019, 9:52 a.m. UTC 
Like in normal vDSOs, when compat vDSOs are enabled the auxiliary
vector symbol AT_SYSINFO_EHDR needs to point at 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.

Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Tested-by: Shijith Thotton <sthotton@marvell.com>
Tested-by: Andre Przywara <andre.przywara@arm.com>
---
 arch/arm64/include/asm/elf.h | 14 ++++++++++++++
 1 file changed, 14 insertions(+)
diff mbox series

Patch

diff --git a/arch/arm64/include/asm/elf.h b/arch/arm64/include/asm/elf.h
index 355d120b78cb..34cabaf78011 100644
--- a/arch/arm64/include/asm/elf.h
+++ b/arch/arm64/include/asm/elf.h
@@ -213,7 +213,21 @@  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 \