sh: Initial vsyscall page support.

This implements initial support for the vsyscall page on SH.
At the moment we leave it configurable due to having nommu
to support from the same code base. We hook it up for the
signal trampoline return at present, with more to be added
later, once uClibc catches up.

Signed-off-by: Paul Mundt <lethal@linux-sh.org>

1 files changed, 20 insertions, 0 deletions

diff --git a/include/asm-sh/elf.h b/include/asm-sh/elf.h
index cc8e5e767345..3a07ab40ac4d 100644
--- a/include/asm-sh/elf.h
+++ b/include/asm-sh/elf.h
@@ -121,4 +121,24 @@ extern int dump_task_fpu (struct task_struct *, elf_fpregset_t *);
 #define ELF_CORE_COPY_FPREGS(tsk, elf_fpregs) dump_task_fpu(tsk, elf_fpregs)
 #endif
 
+#ifdef CONFIG_VSYSCALL
+/* vDSO has arch_setup_additional_pages */
+#define ARCH_HAS_SETUP_ADDITIONAL_PAGES
+struct linux_binprm;
+extern int arch_setup_additional_pages(struct linux_binprm *bprm,
+                                       int executable_stack);
+
+extern unsigned int vdso_enabled;
+extern void __kernel_vsyscall;
+
+#define VDSO_BASE               ((unsigned long)current->mm->context.vdso)
+#define VDSO_SYM(x)             (VDSO_BASE + (unsigned long)(x))
+
+#define ARCH_DLINFO                                             \
+do {                                                            \
+        if (vdso_enabled)                                       \
+                NEW_AUX_ENT(AT_SYSINFO_EHDR, VDSO_BASE);        \
+} while (0)
+#endif /* CONFIG_VSYSCALL */
+
 #endif /* __ASM_SH_ELF_H */