gitback/zig
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

fix elf auxv handling

Browse Source 
Auxillery vectors are not guaranteed to be in any order, this
just happens to work on x86_64.
This commit is contained in:
Shawn Landden 2018-09-08 03:14:30 +00:00
parent 7d6d1d1f60
commit 17cb69cebc
5 changed files with 18 additions and 13 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

5
std/elf.zig
View File

@ -859,6 +859,11 @@ pub const Elf_MIPS_ABIFlags_v0 = extern struct {
flags2: Elf32_Word,
};
pub const Auxv = switch (@sizeOf(usize)) {
4 => Elf32_auxv_t,
8 => Elf64_auxv_t,
else => @compileError("expected pointer size of 32 or 64"),
};
pub const Ehdr = switch (@sizeOf(usize)) {
4 => Elf32_Ehdr,
8 => Elf64_Ehdr,

11
std/os/index.zig
View File

@ -633,16 +633,21 @@ fn posixExecveErrnoToErr(err: usize) PosixExecveError {
};
}
pub var linux_aux_raw = []usize{0} ** 38;
pub var linux_elf_aux_maybe: ?[*]std.elf.Auxv = undefined;
pub var posix_environ_raw: [][*]u8 = undefined;
/// See std.elf for the constants.
pub fn linuxGetAuxVal(index: usize) usize {
if (builtin.link_libc) {
return usize(std.c.getauxval(index));
} else {
return linux_aux_raw[index];
} else if (linux_elf_aux_maybe) |auxv| {
var i: usize = 0;
while (auxv[i].a_type != std.elf.AT_NULL) : (i += 1) {
if (auxv[i].a_type == index)
return auxv[i].a_un.a_val;
}
}
return 0;
}
pub fn getBaseAddress() usize {

6
std/os/linux/arm64.zig
View File

@ -282,10 +282,8 @@ pub const SYS_io_pgetevents = 292;
pub const SYS_syscalls = 293;
pub const VDSO_USEFUL = true;
pub const VDSO_CGT_SYM = "__vdso_clock_gettime";
pub const VDSO_CGT_VER = "LINUX_2.6";
pub const VDSO_GETCPU_SYM = "__vdso_getcpu";
pub const VDSO_GETCPU_VER = "LINUX_2.6";
pub const VDSO_CGT_SYM = "__kernel_clock_gettime";
pub const VDSO_CGT_VER = "LINUX_2.6.39";
pub fn syscall0(number: usize) usize {
return asm volatile ("svc #0"

2
std/os/linux/vdso.zig
View File

@ -5,7 +5,7 @@ const cstr = std.cstr;
const mem = std.mem;
pub fn lookup(vername: []const u8, name: []const u8) usize {
const vdso_addr = std.os.linux_aux_raw[std.elf.AT_SYSINFO_EHDR];
const vdso_addr = std.os.linuxGetAuxVal(std.elf.AT_SYSINFO_EHDR);
if (vdso_addr == 0) return 0;
const eh = @intToPtr(*elf.Ehdr, vdso_addr);

7
std/special/bootstrap.zig
View File

@ -59,11 +59,8 @@ fn posixCallMainAndExit() noreturn {
const envp = @ptrCast([*][*]u8, envp_optional)[0..envp_count];
if (builtin.os == builtin.Os.linux) {
const auxv = @ptrCast([*]usize, envp.ptr + envp_count + 1);
var i: usize = 0;
while (auxv[i] != 0) : (i += 2) {
if (auxv[i] < std.os.linux_aux_raw.len) std.os.linux_aux_raw[auxv[i]] = auxv[i + 1];
}
std.debug.assert(std.os.linux_aux_raw[std.elf.AT_PAGESZ] == std.os.page_size);
std.os.linux_elf_aux_maybe = @ptrCast([*]std.elf.Auxv, auxv);
std.debug.assert(std.os.linuxGetAuxVal(std.elf.AT_PAGESZ) == std.os.page_size);
}
std.os.posix.exit(callMainWithArgs(argc, argv, envp));