Faasm vs wasi-libc:main

Makefile

@@ -156,7 +156,7 @@ LIBC_TOP_HALF_MUSL_SOURCES = \
         legacy/getpagesize.c \
         thread/thrd_sleep.c \
     ) \
-    $(filter-out %/procfdname.c %/syscall.c %/syscall_ret.c %/vdso.c %/version.c, \
+    $(filter-out %/procfdname.c %/vdso.c %/version.c, \
                  $(wildcard $(LIBC_TOP_HALF_MUSL_SRC_DIR)/internal/*.c)) \
     $(filter-out %/flockfile.c %/funlockfile.c %/__lockfile.c %/ftrylockfile.c \
                  %/rename.c \
@@ -329,6 +329,13 @@ CFLAGS += -mthread-model posix -pthread -ftls-model=local-exec
 # Include cloudlib's directory to access the structure definition of clockid_t
 CFLAGS += -I$(LIBC_BOTTOM_HALF_CLOUDLIBC_SRC)
 endif
+# Faasm: We **must** avoid introducing atomics, but still want to include the
+# ability to do threading. See:
+# https://reviews.llvm.org/D59281
+CFLAGS += -mno-atomics -mthread-model posix -ftls-model=local-exec
+
+# Faasm: dd Faasm def for conditional compilation of some headers
+CFLAGS += -D__faasm
 
 # Expose the public headers to the implementation. We use `-isystem` for
 # purpose for two reasons:
@@ -343,6 +350,8 @@ endif
 #    and/or `#include_next` the public headers. `-isystem` (like
 #    `-idirafter`) comes later in the search path than `-I`.
 CFLAGS += -isystem "$(SYSROOT_INC)"
+# Set the sysroot.
+CFLAGS += --sysroot="$(SYSROOT)"
 
 # These variables describe the locations of various files and directories in
 # the build tree.
@@ -387,7 +396,7 @@ SYSROOT_SHARE = $(SYSROOT)/share/$(TARGET_TRIPLE)
 # sysroot's include directory.
 MUSL_OMIT_HEADERS :=
 
-# Remove files which aren't headers (we generate alltypes.h below).
+# Remove files which aren't headers (we generate alltypes.h and syscall.h below).
 MUSL_OMIT_HEADERS += \
     "bits/syscall.h.in" \
     "bits/alltypes.h.in" \
@@ -402,6 +411,9 @@ MUSL_OMIT_HEADERS += \
 MUSL_OMIT_HEADERS += \
     "bits/errno.h"
 
+ifeq ($(THREAD_MODEL), faasm)
+# Include all other headers in Faasm
+else
 # Remove headers that aren't supported yet or that aren't relevant for WASI.
 MUSL_OMIT_HEADERS += \
     "sys/procfs.h" \
@@ -462,6 +474,7 @@ MUSL_OMIT_HEADERS += \
     "libintl.h" \
     "sys/sysmacros.h" \
     "aio.h"
+endif
 
 ifeq ($(THREAD_MODEL), single)
 # Remove headers not supported in single-threaded mode.
@@ -503,13 +516,17 @@ $(MUSL_PRINTSCAN_NO_FLOATING_POINT_OBJS): CFLAGS += \
 	    -D__wasilibc_printscan_no_floating_point \
 	    -D__wasilibc_printscan_floating_point_support_option="\"remove -lc-printscan-no-floating-point from the link command\""
 
+# Faasm: we disable bulk-memory in Faasm as it breaks our page-granular memory
+# management model
+ifneq ($(THREAD_MODEL), faasm)
 # TODO: apply -mbulk-memory globally, once
 # https://github.com/llvm/llvm-project/issues/52618 is resolved
 $(BULK_MEMORY_OBJS): CFLAGS += \
         -mbulk-memory
 
 $(BULK_MEMORY_OBJS): CFLAGS += \
         -DBULK_MEMORY_THRESHOLD=$(BULK_MEMORY_THRESHOLD)
+endif
 
 $(LIBWASI_EMULATED_SIGNAL_MUSL_OBJS): CFLAGS += \
 	    -D_WASI_EMULATED_SIGNAL
@@ -573,6 +590,11 @@ include_dirs:
 	    $(LIBC_TOP_HALF_MUSL_DIR)/include/alltypes.h.in \
 	    > "$(SYSROOT_INC)/bits/alltypes.h"
 
+	# Generate musl's syscall header.
+	sed -n -e s/__NR_/SYS_/p < \
+	    $(LIBC_TOP_HALF_MUSL_DIR)/arch/wasm32/bits/syscall.h.in \
+	    > "$(SYSROOT_INC)/bits/syscall.h"
+
 	# Copy in the bulk of musl's public header files.
 	cp -r "$(LIBC_TOP_HALF_MUSL_INC)"/* "$(SYSROOT_INC)"
 	# Copy in the musl's "bits" header files.
@@ -617,8 +639,11 @@ finish: startup_files libc
 # alloctor (providing malloc, calloc, free, etc). Skip this step if the build
 # is done without a malloc implementation.
 ifneq ($(MALLOC_IMPL),none)
+	# Faasm: we don't do the symbol check
+ifneq ($(THREAD_MODEL), faasm)
 finish: check-symbols
 endif
+endif
 
 DEFINED_SYMBOLS = $(SYSROOT_SHARE)/defined-symbols.txt
 UNDEFINED_SYMBOLS = $(SYSROOT_SHARE)/undefined-symbols.txt

dlmalloc/src/dlmalloc.c

@@ -9,8 +9,23 @@
 // WebAssembly doesn't have mmap-style memory allocation.
 #define HAVE_MMAP 0
 
+#ifdef __faasm
+// Faasm supports memory growth and shrinkage with sbrk-style positive and
+// negative allocation. We need to be explicit about sbrk usage (HAVE_MORECORE
+// set to 1) and not mmap/munmap usage (HAVE_MMAP set to 0, default in WASM).
+// Note that this does not mean that we don't support application code using
+// mmap/munmap, it means that heap is only managed with sbrk
+#define HAVE_MORECORE 1
+#define MORECORE_CONTIGUOUS 1
+
+// We don't shrink the linear memory, but claim the pages for the runtime, and
+// move the offset down, so that subsequent allocations can re-use the free-ed
+// memory
+#define MORECORE_CANNOT_TRIM 0
+#else
 // WebAssembly doesn't support shrinking linear memory.
 #define MORECORE_CANNOT_TRIM 1
+#endif
 
 // Disable sanity checks to reduce code size.
 #define ABORT __builtin_unreachable()

libc-bottom-half/cloudlibc/src/libc/fcntl/fcntl.c

@@ -55,6 +55,16 @@ int fcntl(int fildes, int cmd, ...) {
       }
       return 0;
     }
+    case F_DUPFD: {
+      int new_fd = -1;
+      __wasi_errno_t error = __wasi_fd_dup(fildes, &new_fd);
+
+      if(error != 0) {
+        errno = error;
+        return -1;
+      }
+      return new_fd;
+    }
     default:
       errno = EINVAL;
       return -1;

libc-bottom-half/headers/public/__header_fcntl.h

@@ -4,6 +4,7 @@
 #include <wasi/api.h>
 #include <__seek.h>
 #include <__mode_t.h>
+#include <__typedef_off_t.h>
 
 #define O_APPEND __WASI_FDFLAGS_APPEND
 #define O_DSYNC __WASI_FDFLAGS_DSYNC
@@ -44,6 +45,7 @@
 #define POSIX_FADV_SEQUENTIAL __WASI_ADVICE_SEQUENTIAL
 #define POSIX_FADV_WILLNEED __WASI_ADVICE_WILLNEED
 
+#define F_DUPFD (0)
 #define F_GETFD (1)
 #define F_SETFD (2)
 #define F_GETFL (3)
@@ -57,5 +59,8 @@
 #define AT_REMOVEDIR        (0x4)
 
 #define AT_FDCWD (-2)
+#ifdef __faasm
+int lockf(int, int, off_t);
+#endif
 
 #endif

libc-bottom-half/headers/public/__header_poll.h

@@ -9,6 +9,7 @@
 
 #define POLLIN POLLRDNORM
 #define POLLOUT POLLWRNORM
+#define POLLPRI 0x3
 
 #define POLLERR 0x1000
 #define POLLHUP 0x2000

libc-bottom-half/headers/public/__header_sys_resource.h

@@ -2,16 +2,36 @@
 #define __wasilibc___header_sys_resource_h
 
 #include <__struct_rusage.h>
+#include <__struct_rlimit.h>
 
 #define RUSAGE_SELF 1
 #define RUSAGE_CHILDREN 2
 
+#define RLIMIT_CPU     0
+#define RLIMIT_FSIZE   1
+#define RLIMIT_DATA    2
+#define RLIMIT_STACK   3
+#define RLIMIT_CORE    4
+#ifndef RLIMIT_RSS
+#define RLIMIT_RSS     5
+#define RLIMIT_NPROC   6
+#define RLIMIT_NOFILE  7
+#define RLIMIT_MEMLOCK 8
+#define RLIMIT_AS      9
+#endif
+
 #ifdef __cplusplus
 extern "C" {
 #endif
 
+int getrlimit (int resource, struct rlimit *);
+int setrlimit (int resource, const struct rlimit *);
+
 int getrusage(int who, struct rusage *usage);
 
+int getpriority (int which, id_t who);
+int setpriority (int which, id_t who, int prio);
+
 #ifdef __cplusplus
 }
 #endif

libc-bottom-half/headers/public/__struct_rlimit.h

@@ -0,0 +1,13 @@
+#ifndef __wasilibc___struct_rlimit_h
+#define __wasilibc___struct_rlimit_h
+
+#include <__struct_timeval.h>
+
+typedef unsigned long long rlim_t;
+
+struct rlimit {
+    rlim_t rlim_cur;
+    rlim_t rlim_max;
+};
+
+#endif

libc-bottom-half/headers/public/wasi/api.h

@@ -745,7 +745,7 @@ _Static_assert(_Alignof(__wasi_whence_t) == 1, "witx calculated align");
 
 /**
  * A reference to the offset of a directory entry.
- * 
+ *
  * The value 0 signifies the start of the directory.
  */
 typedef uint64_t __wasi_dircookie_t;
@@ -1737,6 +1737,13 @@ __wasi_errno_t __wasi_fd_seek(
 __wasi_errno_t __wasi_fd_sync(
     __wasi_fd_t fd
 ) __attribute__((__warn_unused_result__));
+/**
+ * Faasm: add header for wasi_fd_dup
+ */
+__wasi_errno_t __wasi_fd_dup(
+    int fildes,
+    __wasi_fd_t *new_fd
+) __attribute__((__warn_unused_result__));
 /**
  * Return the current offset of a file descriptor.
  * Note: This is similar to `lseek(fd, 0, SEEK_CUR)` in POSIX.

libc-bottom-half/sources/sbrk.c

@@ -3,8 +3,16 @@
 #include <errno.h>
 #include <__macro_PAGESIZE.h>
 
+#ifdef __faasm
+    extern void* __sbrk(intptr_t increment);
+#endif
+
 // Bare-bones implementation of sbrk.
 void *sbrk(intptr_t increment) {
+#ifdef __faasm
+    // In Faasm we defer to our custom sbrk implementation
+    return __sbrk(increment);
+#else
     // sbrk(0) returns the current memory size.
     if (increment == 0) {
         // The wasm spec doesn't guarantee that memory.grow of 0 always succeeds.
@@ -29,4 +37,5 @@ void *sbrk(intptr_t increment) {
     }
 
     return (void *)(old * PAGESIZE);
+#endif
 }

libc-top-half/musl/arch/wasm32/bits/fenv.h

@@ -0,0 +1,22 @@
+#define FE_ALL_EXCEPT 0
+
+#define FE_INVALID    1
+#define FE_DIVBYZERO  4
+#define FE_OVERFLOW   8
+#define FE_UNDERFLOW  16
+#define FE_INEXACT    32
+#define FE_TONEAREST  0
+#define FE_DOWNWARD   0x400
+#define FE_UPWARD     0x800
+#define FE_TOWARDZERO 0xc00
+
+
+typedef unsigned long fexcept_t;
+
+typedef struct {
+	unsigned long __cw;
+} fenv_t;
+
+#define FE_DFL_ENV      ((const fenv_t *) -1)
+
+

libc-top-half/musl/arch/wasm32/bits/setjmp.h

@@ -0,0 +1 @@
+typedef unsigned long __jmp_buf[6];