summaryrefslogtreecommitdiff
path: root/arch/tile/mm/elf.c
diff options
context:
space:
mode:
Diffstat (limited to 'arch/tile/mm/elf.c')
-rw-r--r--arch/tile/mm/elf.c164
1 files changed, 164 insertions, 0 deletions
diff --git a/arch/tile/mm/elf.c b/arch/tile/mm/elf.c
new file mode 100644
index 0000000..55e58e9
--- /dev/null
+++ b/arch/tile/mm/elf.c
@@ -0,0 +1,164 @@
+/*
+ * Copyright 2010 Tilera Corporation. All Rights Reserved.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation, version 2.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
+ * NON INFRINGEMENT. See the GNU General Public License for
+ * more details.
+ */
+
+#include <linux/mm.h>
+#include <linux/pagemap.h>
+#include <linux/binfmts.h>
+#include <linux/compat.h>
+#include <linux/mman.h>
+#include <linux/elf.h>
+#include <asm/pgtable.h>
+#include <asm/pgalloc.h>
+#include <asm/sections.h>
+
+/* Notify a running simulator, if any, that an exec just occurred. */
+static void sim_notify_exec(const char *binary_name)
+{
+ unsigned char c;
+ do {
+ c = *binary_name++;
+ __insn_mtspr(SPR_SIM_CONTROL,
+ (SIM_CONTROL_OS_EXEC
+ | (c << _SIM_CONTROL_OPERATOR_BITS)));
+
+ } while (c);
+}
+
+static int notify_exec(void)
+{
+ int retval = 0; /* failure */
+ struct vm_area_struct *vma = current->mm->mmap;
+ while (vma) {
+ if ((vma->vm_flags & VM_EXECUTABLE) && vma->vm_file)
+ break;
+ vma = vma->vm_next;
+ }
+ if (vma) {
+ char *buf = (char *) __get_free_page(GFP_KERNEL);
+ if (buf) {
+ char *path = d_path(&vma->vm_file->f_path,
+ buf, PAGE_SIZE);
+ if (!IS_ERR(path)) {
+ sim_notify_exec(path);
+ retval = 1;
+ }
+ free_page((unsigned long)buf);
+ }
+ }
+ return retval;
+}
+
+/* Notify a running simulator, if any, that we loaded an interpreter. */
+static void sim_notify_interp(unsigned long load_addr)
+{
+ size_t i;
+ for (i = 0; i < sizeof(load_addr); i++) {
+ unsigned char c = load_addr >> (i * 8);
+ __insn_mtspr(SPR_SIM_CONTROL,
+ (SIM_CONTROL_OS_INTERP
+ | (c << _SIM_CONTROL_OPERATOR_BITS)));
+ }
+}
+
+
+/* Kernel address of page used to map read-only kernel data into userspace. */
+static void *vdso_page;
+
+/* One-entry array used for install_special_mapping. */
+static struct page *vdso_pages[1];
+
+static int __init vdso_setup(void)
+{
+ vdso_page = (void *)get_zeroed_page(GFP_ATOMIC);
+ memcpy(vdso_page, __rt_sigreturn, __rt_sigreturn_end - __rt_sigreturn);
+ vdso_pages[0] = virt_to_page(vdso_page);
+ return 0;
+}
+device_initcall(vdso_setup);
+
+const char *arch_vma_name(struct vm_area_struct *vma)
+{
+ if (vma->vm_private_data == vdso_pages)
+ return "[vdso]";
+#ifndef __tilegx__
+ if (vma->vm_start == MEM_USER_INTRPT)
+ return "[intrpt]";
+#endif
+ return NULL;
+}
+
+int arch_setup_additional_pages(struct linux_binprm *bprm,
+ int executable_stack)
+{
+ struct mm_struct *mm = current->mm;
+ unsigned long vdso_base;
+ int retval = 0;
+
+ /*
+ * Notify the simulator that an exec just occurred.
+ * If we can't find the filename of the mapping, just use
+ * whatever was passed as the linux_binprm filename.
+ */
+ if (!notify_exec())
+ sim_notify_exec(bprm->filename);
+
+ down_write(&mm->mmap_sem);
+
+ /*
+ * MAYWRITE to allow gdb to COW and set breakpoints
+ *
+ * Make sure the vDSO gets into every core dump. Dumping its
+ * contents makes post-mortem fully interpretable later
+ * without matching up the same kernel and hardware config to
+ * see what PC values meant.
+ */
+ vdso_base = VDSO_BASE;
+ retval = install_special_mapping(mm, vdso_base, PAGE_SIZE,
+ VM_READ|VM_EXEC|
+ VM_MAYREAD|VM_MAYWRITE|VM_MAYEXEC|
+ VM_ALWAYSDUMP,
+ vdso_pages);
+
+#ifndef __tilegx__
+ /*
+ * Set up a user-interrupt mapping here; the user can't
+ * create one themselves since it is above TASK_SIZE.
+ * We make it unwritable by default, so the model for adding
+ * interrupt vectors always involves an mprotect.
+ */
+ if (!retval) {
+ unsigned long addr = MEM_USER_INTRPT;
+ addr = mmap_region(NULL, addr, INTRPT_SIZE,
+ MAP_FIXED|MAP_ANONYMOUS|MAP_PRIVATE,
+ VM_READ|VM_EXEC|
+ VM_MAYREAD|VM_MAYWRITE|VM_MAYEXEC, 0);
+ if (addr > (unsigned long) -PAGE_SIZE)
+ retval = (int) addr;
+ }
+#endif
+
+ up_write(&mm->mmap_sem);
+
+ return retval;
+}
+
+
+void elf_plat_init(struct pt_regs *regs, unsigned long load_addr)
+{
+ /* Zero all registers. */
+ memset(regs, 0, sizeof(*regs));
+
+ /* Report the interpreter's load address. */
+ sim_notify_interp(load_addr);
+}