1 files changed, 175 insertions, 0 deletions
diff --git a/arch/x86/vdso/vdso2c.c b/arch/x86/vdso/vdso2c.c
new file mode 100644
index 000000000000..450ac6eaf613
--- /dev/null
+++ b/arch/x86/vdso/vdso2c.c
@@ -0,0 +1,175 @@
+#include <inttypes.h>
+#include <stdint.h>
+#include <unistd.h>
+#include <stdarg.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include <fcntl.h>
+#include <err.h>
+
+#include <sys/mman.h>
+#include <sys/types.h>
+
+#include <tools/le_byteshift.h>
+
+#include <linux/elf.h>
+#include <linux/types.h>
+
+const char *outfilename;
+
+/* Symbols that we need in vdso2c. */
+enum {
+	sym_vvar_page,
+	sym_hpet_page,
+	sym_end_mapping,
+};
+
+const int special_pages[] = {
+	sym_vvar_page,
+	sym_hpet_page,
+};
+
+char const * const required_syms[] = {
+	[sym_vvar_page] = "vvar_page",
+	[sym_hpet_page] = "hpet_page",
+	[sym_end_mapping] = "end_mapping",
+	"VDSO32_NOTE_MASK",
+	"VDSO32_SYSENTER_RETURN",
+	"__kernel_vsyscall",
+	"__kernel_sigreturn",
+	"__kernel_rt_sigreturn",
+};
+
+__attribute__((format(printf, 1, 2))) __attribute__((noreturn))
+static void fail(const char *format, ...)
+{
+	va_list ap;
+	va_start(ap, format);
+	fprintf(stderr, "Error: ");
+	vfprintf(stderr, format, ap);
+	unlink(outfilename);
+	exit(1);
+	va_end(ap);
+}
+
+/*
+ * Evil macros to do a little-endian read.
+ */
+#define GLE(x, bits, ifnot)						\
+	__builtin_choose_expr(						\
+		(sizeof(*(x)) == bits/8),				\
+		(__typeof__(*(x)))get_unaligned_le##bits(x), ifnot)
+
+extern void bad_get_le(void);
+#define LAST_LE(x)							\
+	__builtin_choose_expr(sizeof(*(x)) == 1, *(x), bad_get_le())
+
+#define GET_LE(x)							\
+	GLE(x, 64, GLE(x, 32, GLE(x, 16, LAST_LE(x))))
+
+#define NSYMS (sizeof(required_syms) / sizeof(required_syms[0]))
+
+#define BITS 64
+#define GOFUNC go64
+#define Elf_Ehdr Elf64_Ehdr
+#define Elf_Shdr Elf64_Shdr
+#define Elf_Phdr Elf64_Phdr
+#define Elf_Sym Elf64_Sym
+#define Elf_Dyn Elf64_Dyn
+#include "vdso2c.h"
+#undef BITS
+#undef GOFUNC
+#undef Elf_Ehdr
+#undef Elf_Shdr
+#undef Elf_Phdr
+#undef Elf_Sym
+#undef Elf_Dyn
+
+#define BITS 32
+#define GOFUNC go32
+#define Elf_Ehdr Elf32_Ehdr
+#define Elf_Shdr Elf32_Shdr
+#define Elf_Phdr Elf32_Phdr
+#define Elf_Sym Elf32_Sym
+#define Elf_Dyn Elf32_Dyn
+#include "vdso2c.h"
+#undef BITS
+#undef GOFUNC
+#undef Elf_Ehdr
+#undef Elf_Shdr
+#undef Elf_Phdr
+#undef Elf_Sym
+#undef Elf_Dyn
+
+static void go(void *addr, size_t len, FILE *outfile, const char *name)
+{
+	Elf64_Ehdr *hdr = (Elf64_Ehdr *)addr;
+
+	if (hdr->e_ident[EI_CLASS] == ELFCLASS64) {
+		go64(addr, len, outfile, name);
+	} else if (hdr->e_ident[EI_CLASS] == ELFCLASS32) {
+		go32(addr, len, outfile, name);
+	} else {
+		fail("unknown ELF class\n");
+	}
+}
+
+int main(int argc, char **argv)
+{
+	int fd;
+	off_t len;
+	void *addr;
+	FILE *outfile;
+	char *name, *tmp;
+	int namelen;
+
+	if (argc != 3) {
+		printf("Usage: vdso2c INPUT OUTPUT\n");
+		return 1;
+	}
+
+	/*
+	 * Figure out the struct name.  If we're writing to a .so file,
+	 * generate raw output insted.
+	 */
+	name = strdup(argv[2]);
+	namelen = strlen(name);
+	if (namelen >= 3 && !strcmp(name + namelen - 3, ".so")) {
+		name = NULL;
+	} else {
+		tmp = strrchr(name, '/');
+		if (tmp)
+			name = tmp + 1;
+		tmp = strchr(name, '.');
+		if (tmp)
+			*tmp = '\0';
+		for (tmp = name; *tmp; tmp++)
+			if (*tmp == '-')
+				*tmp = '_';
+	}
+
+	fd = open(argv[1], O_RDONLY);
+	if (fd == -1)
+		err(1, "%s", argv[1]);
+
+	len = lseek(fd, 0, SEEK_END);
+	if (len == (off_t)-1)
+		err(1, "lseek");
+
+	addr = mmap(NULL, len, PROT_READ | PROT_WRITE, MAP_PRIVATE, fd, 0);
+	if (addr == MAP_FAILED)
+		err(1, "mmap");
+
+	outfilename = argv[2];
+	outfile = fopen(outfilename, "w");
+	if (!outfile)
+		err(1, "%s", argv[2]);
+
+	go(addr, (size_t)len, outfile, name);
+
+	munmap(addr, len);
+	fclose(outfile);
+
+	return 0;
+}