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-rw-r--r--arch/x86/vdso/vdso2c.c173
1 files changed, 173 insertions, 0 deletions
diff --git a/arch/x86/vdso/vdso2c.c b/arch/x86/vdso/vdso2c.c
new file mode 100644
index 000000000000..deabaf5bfb89
--- /dev/null
+++ b/arch/x86/vdso/vdso2c.c
@@ -0,0 +1,173 @@
+#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 <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))le##bits##toh(x), ifnot)
+
+extern void bad_get_le(uint64_t);
+#define LAST_LE(x) \
+ __builtin_choose_expr(sizeof(x) == 1, (x), bad_get_le(x))
+
+#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;
+}