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Improve threading support further

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This commit is contained in:
Justine Tunney 2022-05-17 04:14:28 -07:00
parent 8bfb70ca3f
commit ce71677156
61 changed files with 882 additions and 747 deletions
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248
libc/runtime/clone.greg.c
View file

@ -26,9 +26,7 @@
#include "libc/intrin/asan.internal.h"
#include "libc/intrin/kprintf.h"
#include "libc/intrin/spinlock.h"
#include "libc/intrin/threaded.internal.h"
#include "libc/intrin/tls.h"
#include "libc/intrin/winthread.internal.h"
#include "libc/intrin/threaded.h"
#include "libc/nt/runtime.h"
#include "libc/nt/thread.h"
#include "libc/nt/thunk/msabi.h"
@ -46,58 +44,22 @@ STATIC_YOINK("gettid"); // for kprintf()
#define __NR_clone_linux 56
#define __NR__lwp_create 309
#define __NR_getcontext_netbsd 307
#define __NR__lwp_setprivate 317
#define __NR_bsdthread_create 0x02000168
#define __NR_thread_fast_set_cthread_self 0x03000003
#define __NR_sysarch 0x000000a5
#define __NR___set_tcb 0x00000149
#define PTHREAD_START_CUSTOM_XNU 0x01000000
#define LWP_DETACHED 0x00000040
#define LWP_SUSPENDED 0x00000080
char __tls[512];
int __errno_global;
extern int __errno_index;
static char tibdefault[64];
privileged void __setup_tls(void) {
int ax, dx;
uint64_t magic;
unsigned char *p;
*(intptr_t *)__tls = (intptr_t)__tls;
*(intptr_t *)(__tls + 0x30) = (intptr_t)__tls;
*(int *)(__tls + 0x3c) = __errno;
if (IsWindows()) {
__errno_index = TlsAlloc();
TlsSetValue(__errno_index, (void *)(intptr_t)__errno);
} else if (IsLinux()) {
asm volatile("syscall"
: "=a"(ax)
: "0"(__NR_linux_arch_prctl), "D"(ARCH_SET_FS), "S"(__tls)
: "rcx", "r11", "memory");
} else if (IsFreebsd()) {
asm volatile("syscall"
: "=a"(ax)
: "0"(__NR_sysarch), "D"(129), "S"(__tls)
: "rcx", "r11", "memory", "cc");
} else if (IsXnu()) {
asm volatile("syscall"
: "=a"(ax)
: "0"(__NR_thread_fast_set_cthread_self),
"D"((intptr_t)__tls - 0x30)
: "rcx", "r11", "memory", "cc");
} else if (IsOpenbsd()) {
asm volatile("syscall"
: "=a"(ax)
: "0"(__NR___set_tcb), "D"(__tls)
: "rcx", "r11", "memory", "cc");
} else if (IsNetbsd()) {
asm volatile("syscall"
: "=a"(ax), "=d"(dx)
: "0"(__NR__lwp_setprivate), "D"(__tls)
: "rcx", "r11", "memory", "cc");
}
__hastls = true;
}
struct WinThread {
uint32_t tid;
int flags;
int *ctid;
void *tls;
int (*func)(void *);
void *arg;
};
uint32_t WinThreadThunk(void *warg);
asm(".section\t.text.windows,\"ax\",@progbits\n\t"
@ -115,20 +77,19 @@ __attribute__((__used__, __no_reorder__))
static textwindows wontreturn void
WinThreadMain(struct WinThread *wt) {
int rc;
if (wt->flags & CLONE_SETTLS) {
TlsSetValue(__tls_index, wt->tls);
}
if (wt->flags & CLONE_CHILD_SETTID) {
*wt->ctid = wt->tid;
}
rc = wt->func(wt->arg);
if (wt->flags & CLONE_CHILD_CLEARTID) {
*wt->ctid = 0;
}
_Exit1(rc);
}
static textwindows int CloneWindows(int (*func)(void *), char *stk,
size_t stksz, int flags, void *arg,
int *ptid, void *tls, size_t tlssz,
int *ctid) {
void *tls, size_t tlssz, int *ctid) {
int64_t h;
struct WinThread *wt;
wt = (struct WinThread *)(((intptr_t)(stk + stksz) -
@ -138,14 +99,11 @@ static textwindows int CloneWindows(int (*func)(void *), char *stk,
wt->ctid = ctid;
wt->func = func;
wt->arg = arg;
wt->tls = tls;
if ((h = CreateThread(0, 0, WinThreadThunk, wt, 0, &wt->tid))) {
CloseHandle(h);
if (flags & CLONE_PARENT_SETTID) {
*ptid = wt->tid;
}
return wt->tid;
} else {
__releasefd(wt->tid);
return -1;
}
}
@ -179,14 +137,11 @@ XnuThreadMain(void *pthread, int tid, int (*func)(void *arg), void *arg,
*(int *)sp[2] = tid;
}
rc = func(arg);
if (sp[4] & CLONE_CHILD_CLEARTID) {
*(int *)sp[2] = 0;
}
_Exit1(rc);
}
static int CloneXnu(int (*fn)(void *), char *stk, size_t stksz, int flags,
void *arg, int *ptid, void *tls, size_t tlssz, int *ctid) {
void *arg, void *tls, size_t tlssz, int *ctid) {
int rc;
bool failed;
intptr_t *sp;
@ -212,9 +167,6 @@ static int CloneXnu(int (*fn)(void *), char *stk, size_t stksz, int flags,
_seizelock(sp); // TODO: How can we get the tid without locking?
if ((rc = bsdthread_create(fn, arg, sp, 0, PTHREAD_START_CUSTOM_XNU)) != -1) {
_spinlock(sp);
if (flags & CLONE_PARENT_SETTID) {
*ptid = sp[1];
}
rc = sp[1];
}
return rc;
@ -236,15 +188,11 @@ FreebsdThreadMain(intptr_t *sp) {
*(int *)sp[2] = sp[4];
}
rc = ((int (*)(intptr_t))sp[0])(sp[1]);
if (sp[3] & CLONE_CHILD_CLEARTID) {
*(int *)sp[2] = 0;
}
_Exit1(rc);
}
static int CloneFreebsd(int (*func)(void *), char *stk, size_t stksz, int flags,
void *arg, int *ptid, void *tls, size_t tlssz,
int *ctid) {
void *arg, void *tls, size_t tlssz, int *ctid) {
int ax;
bool failed;
int64_t tid;
@ -270,15 +218,11 @@ static int CloneFreebsd(int (*func)(void *), char *stk, size_t stksz, int flags,
: CFLAG_CONSTRAINT(failed), "=a"(ax)
: "1"(__NR_thr_new), "D"(&params), "S"(sizeof(params))
: "rcx", "rdx", "r8", "r9", "r10", "r11", "memory");
if (!failed) {
if (flags & CLONE_PARENT_SETTID) {
*ptid = tid;
}
return tid;
} else {
if (failed) {
errno = ax;
return -1;
tid = -1;
}
return tid;
}
struct __tfork {
@ -313,15 +257,11 @@ static privileged wontreturn void
OpenbsdThreadMain(intptr_t *sp) {
int rc;
rc = ((int (*)(intptr_t))sp[0])(sp[1]);
if (sp[3] & CLONE_CHILD_CLEARTID) {
*(int *)sp[2] = 0;
}
_Exit1(rc);
}
static int CloneOpenbsd(int (*func)(void *), char *stk, size_t stksz, int flags,
void *arg, int *ptid, void *tls, size_t tlssz,
int *ctid) {
void *arg, void *tls, size_t tlssz, int *ctid) {
int tid;
intptr_t *sp;
struct __tfork params;
@ -333,11 +273,7 @@ static int CloneOpenbsd(int (*func)(void *), char *stk, size_t stksz, int flags,
params.tf_stack = sp;
params.tf_tcb = flags & CLONE_SETTLS ? tls : 0;
params.tf_tid = flags & CLONE_CHILD_SETTID ? ctid : 0;
if ((tid = __tfork(&params, sizeof(params), sp)) > 0) {
if (flags & CLONE_PARENT_SETTID) {
*ptid = tid;
}
} else {
if ((tid = __tfork(&params, sizeof(params), sp)) < 0) {
errno = -tid;
tid = -1;
}
@ -351,15 +287,11 @@ static wontreturn void NetbsdThreadMain(void *arg, int (*func)(void *arg),
*ctid = *tid;
}
rc = func(arg);
if (flags & CLONE_CHILD_CLEARTID) {
*ctid = 0;
}
_Exit1(rc);
}
static int CloneNetbsd(int (*func)(void *), char *stk, size_t stksz, int flags,
void *arg, int *ptid, void *tls, size_t tlssz,
int *ctid) {
void *arg, void *tls, size_t tlssz, int *ctid) {
// NetBSD has its own clone() and it works, but it's technically a
// second-class API, intended to help Linux folks migrate to this!
// We put it on the thread's stack, to avoid locking this function
@ -414,9 +346,6 @@ static int CloneNetbsd(int (*func)(void *), char *stk, size_t stksz, int flags,
: "1"(__NR__lwp_create), "D"(ctx), "S"(LWP_DETACHED), "2"(tid)
: "rcx", "r11", "memory");
if (!failed) {
if (flags & CLONE_PARENT_SETTID) {
*ptid = *tid;
}
return *tid;
} else {
errno = ax;
@ -453,49 +382,65 @@ static int CloneLinux(int (*func)(void *), char *stk, size_t stksz, int flags,
* Creates thread.
*
* Threads are created in a detached manner. They currently can't be
* synchronized using wait() and posix signals. Threads created by this
* synchronized using wait() or posix signals. Threads created by this
* function should be synchronized using shared memory operations.
*
* Any memory that's required by this system call wrapper is allocated
* to the top of your stack. This is normally about 64 bytes, although
* on NetBSD it's currently 800.
*
* Your function is called from within the stack you specify. A return
* address is pushed onto your stack, that causes returning to jump to
* _Exit1() which terminates the thread. Even though the callback says
* it supports a return code, that'll only work on Linux and Windows.
*
* The `tls` parameter is for thread-local storage. If you specify this
* then clone() will implicitly rewire libc (e.g. errno) to use TLS:
*
* static char tib[64];
* __initialize_tls(tib);
* __install_tls(tib);
*
* If you want a main process TLS size that's larger call it manually.
* Once you've done the above and/or started creating your own threads
* you'll be able to access your `tls` thread information block, using
*
* char *p = __get_tls();
* printf("errno is %d\n", *(int *)(p + 0x3c));
*
* This function follows the same ABI convention as the Linux userspace
* libraries, with a few small changes. The varargs has been removed to
* help prevent broken code, and the stack size and tls size parameters
* are introduced for compatibility with FreeBSD.
*
* To keep this system call lightweight, only the thread creation use
* case is polyfilled across platforms. For example, if you want fork
* that works on OpenBSD for example, don't do it with clone(SIGCHLD)
* and please just call fork(). Even if you do that on Linux, it will
* effectively work around libc features like atfork(), so that means
* other calls like getpid() may return incorrect values.
*
* @param func is your callback function
* @param stk points to the bottom of a caller allocated stack, which
* must be null when fork() and vfork() equivalent flags are used
* and furthermore this must be mmap()'d using MAP_STACK in order
* to work on OpenBSD
* @param stksz is the size of that stack in bytes which must be zero
* if the fork() or vfork() equivalent flags are used it's highly
* recommended that this value be GetStackSize(), or else kprintf
* and other runtime services providing memory safety can't do as
* good and quick of a job; this value must be 16-aligned plus it
* must be at minimum 4096 bytes in size
* @param flags usually has one of
* - `SIGCHLD` will delegate to fork()
* - `CLONE_VFORK|CLONE_VM|SIGCHLD` means vfork()
* must be allocated via mmap() using the MAP_STACK flag, or else
* you won't get optimal performance and it won't work on OpenBSD
* @param stksz is the size of that stack in bytes, we recommend that
* that this be set to GetStackSize() or else memory safety tools
* like kprintf() can't do as good and quick of a job; this value
* must be 16-aligned plus it must be at least 4192 bytes in size
* and it's advised to have the bottom-most page, be a guard page
* @param flags should have:
* - `CLONE_THREAD|CLONE_VM|CLONE_FS|CLONE_FILES|CLONE_SIGHAND`
* as part high bytes, and the low order byte may optionally contain
* a signal e.g. SIGCHLD, to enable parent notification on terminate
* although the signal isn't supported on non-Linux and non-NetBSD
* at the moment; 'flags' may optionally bitwise or the following:
* - `CLONE_PARENT_SETTID` is needed for `ctid` should be set
* - `CLONE_CHILD_SETTID` is needed for `ptid` should be set
* - `CLONE_SETTLS` is needed to set `%fs` segment to `tls`
* and may optionally bitwise any of the following:
* - `CLONE_CHILD_SETTID` is needed too if you use `ctid`
* - `CLONE_SETTLS` is needed too if you set `tls`
* @param arg will be passed to your callback
* @param ptid lets the parent receive the child thread id;
* this parameter is ignored if `CLONE_PARENT_SETTID` is not set
* @param tls may be used to set the thread local storage segment;
* this parameter is ignored if `CLONE_SETTLS` is not set
* @param tlssz is the size of tls in bytes
* @param ctid lets the child receive its thread id;
* this parameter is ignored if `CLONE_CHILD_SETTID` is not set
* @return tid on success and 0 to the child, or -1 w/ errno
* @param tlssz is the size of tls in bytes which must be at least 64
* @param ctid lets the child receive its thread id without having to
* call gettid() and is ignored if `CLONE_CHILD_SETTID` isn't set
* @return tid of child on success, or -1 w/ errno
* @threadsafe
*/
int clone(int (*func)(void *), void *stk, size_t stksz, int flags, void *arg,
@ -503,11 +448,11 @@ int clone(int (*func)(void *), void *stk, size_t stksz, int flags, void *arg,
int rc;
__threaded = true;
if (tls && !__hastls) {
__setup_tls();
if (tls && !__tls_enabled) {
__initialize_tls(tibdefault);
__install_tls(tibdefault);
}
// verify memory is kosher
if (IsAsan() &&
((stksz > PAGESIZE &&
!__asan_is_valid((char *)stk + PAGESIZE, stksz - PAGESIZE)) ||
@ -518,54 +463,27 @@ int clone(int (*func)(void *), void *stk, size_t stksz, int flags, void *arg,
((flags & CLONE_CHILD_SETTID) &&
!__asan_is_valid(ctid, sizeof(*ctid))))) {
rc = efault();
}
// delegate to bona fide clone()
else if (IsLinux()) {
} else if (!IsTiny() &&
(((flags & CLONE_VM) && (stksz < PAGESIZE || (stksz & 15))) ||
((flags & CLONE_SETTLS) && (tlssz < 64 || (tlssz & 7))))) {
rc = einval();
} else if (IsLinux()) {
rc = CloneLinux(func, stk, stksz, flags, arg, ptid, tls, tlssz, ctid);
}
// polyfill fork() and vfork() use cases on platforms without clone()
else if ((SupportsWindows() || SupportsBsd()) &&
flags == (CLONE_VFORK | CLONE_VM | SIGCHLD)) {
if (IsTiny()) {
rc = einval();
} else if (!arg && !stksz) {
return vfork(); // don't log clone()
} else {
rc = einval();
}
} else if ((SupportsWindows() || SupportsBsd()) && flags == SIGCHLD) {
if (IsTiny()) {
rc = eopnotsupp();
} else if (!arg && !stksz) {
return fork(); // don't log clone()
} else {
rc = einval();
}
}
// we now assume we're creating a thread
// these platforms can't do signals the way linux does
else if (!IsTiny() && ((stksz < PAGESIZE || (stksz & 15)) ||
(flags & ~(CLONE_SETTLS | CLONE_PARENT_SETTID |
CLONE_CHILD_SETTID)) !=
(CLONE_THREAD | CLONE_VM | CLONE_FS | CLONE_FILES |
CLONE_SIGHAND))) {
} else if (!IsTiny() && (flags & ~(CLONE_SETTLS | CLONE_PARENT_SETTID |
CLONE_CHILD_SETTID)) !=
(CLONE_THREAD | CLONE_VM | CLONE_FS |
CLONE_FILES | CLONE_SIGHAND)) {
rc = einval();
} else if (IsXnu()) {
rc = CloneXnu(func, stk, stksz, flags, arg, ptid, tls, tlssz, ctid);
rc = CloneXnu(func, stk, stksz, flags, arg, tls, tlssz, ctid);
} else if (IsFreebsd()) {
rc = CloneFreebsd(func, stk, stksz, flags, arg, ptid, tls, tlssz, ctid);
rc = CloneFreebsd(func, stk, stksz, flags, arg, tls, tlssz, ctid);
} else if (IsNetbsd()) {
rc = CloneNetbsd(func, stk, stksz, flags, arg, ptid, tls, tlssz, ctid);
rc = CloneNetbsd(func, stk, stksz, flags, arg, tls, tlssz, ctid);
} else if (IsOpenbsd()) {
rc = CloneOpenbsd(func, stk, stksz, flags, arg, ptid, tls, tlssz, ctid);
}
// These platforms can't do segment registers like linux does
else if (IsWindows()) {
rc = CloneWindows(func, stk, stksz, flags, arg, ptid, tls, tlssz, ctid);
rc = CloneOpenbsd(func, stk, stksz, flags, arg, tls, tlssz, ctid);
} else if (IsWindows()) {
rc = CloneWindows(func, stk, stksz, flags, arg, tls, tlssz, ctid);
} else {
rc = enosys();
}

4
libc/runtime/getsymboltable.greg.c
View file

@ -20,6 +20,7 @@
#include "libc/bits/bits.h"
#include "libc/bits/weaken.h"
#include "libc/calls/strace.internal.h"
#include "libc/intrin/spinlock.h"
#include "libc/macros.internal.h"
#include "libc/runtime/runtime.h"
#include "libc/runtime/symbols.internal.h"
@ -29,6 +30,7 @@
#include "libc/zip.h"
#include "libc/zipos/zipos.internal.h"
static char g_lock;
static struct SymbolTable *g_symtab;
/**
@ -118,6 +120,7 @@ static struct SymbolTable *GetSymbolTableFromElf(void) {
*/
struct SymbolTable *GetSymbolTable(void) {
struct Zipos *z;
if (_trylock(&g_lock)) return 0;
if (!g_symtab && !__isworker) {
if (weaken(__zipos_get) && (z = weaken(__zipos_get)())) {
if ((g_symtab = GetSymbolTableFromZip(z))) {
@ -131,6 +134,7 @@ struct SymbolTable *GetSymbolTable(void) {
g_symtab = GetSymbolTableFromElf();
}
}
_spunlock(&g_lock);
return g_symtab;
}

2
libc/runtime/memtrack.internal.h
View file

@ -46,7 +46,7 @@ struct MemoryIntervals {
size_t i, n;
struct MemoryInterval *p;
struct MemoryInterval s[OPEN_MAX];
_Alignas(64) char lock;
_Alignas(64) int lock;
};
extern hidden struct MemoryIntervals _mmi;