cosmopolitan/libc/mem/malloc.S

/*-*- mode:unix-assembly; indent-tabs-mode:t; tab-width:8; coding:utf-8     -*-│
│vi: set et ft=asm ts=8 tw=8 fenc=utf-8                                     :vi│
╞══════════════════════════════════════════════════════════════════════════════╡
│ Copyright 2020 Justine Alexandra Roberts Tunney                              │
│                                                                              │
│ Permission to use, copy, modify, and/or distribute this software for         │
│ any purpose with or without fee is hereby granted, provided that the         │
│ above copyright notice and this permission notice appear in all copies.      │
│                                                                              │
│ THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL                │
│ WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED                │
│ WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE             │
│ AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL         │
│ DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR        │
│ PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER               │
│ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR             │
│ PERFORMANCE OF THIS SOFTWARE.                                                │
╚─────────────────────────────────────────────────────────────────────────────*/
#include "libc/macros.internal.h"

//	Allocates uninitialized memory.
//
//	Returns a pointer to a newly allocated chunk of at least n bytes, or
//	null if no space is available, in which case errno is set to ENOMEM
//	on ANSI C systems.
//
//	If n is zero, malloc returns a minimum-sized chunk. (The minimum size
//	is 32 bytes on 64bit systems.) Note that size_t is an unsigned type,
//	so calls with arguments that would be negative if signed are
//	interpreted as requests for huge amounts of space, which will often
//	fail. The maximum supported value of n differs across systems, but is
//	in all cases less than the maximum representable value of a size_t.
//
//	@param	rdi is number of bytes needed, coerced to 1+
//	@return	new memory, or NULL w/ errno
//	@threadsafe
malloc:	jmp	*hook_malloc(%rip)
	.endfn	malloc,globl
Polish up repository and other revisions 2020-06-16 13:38:43 +00:00			`/-- mode:unix-assembly; indent-tabs-mode:t; tab-width:8; coding:utf-8 -*-│`
Initial import 2020-06-15 14:18:57 +00:00			`│vi: set et ft=asm ts=8 tw=8 fenc=utf-8 :vi│`
			`╞══════════════════════════════════════════════════════════════════════════════╡`
			`│ Copyright 2020 Justine Alexandra Roberts Tunney │`
			`│ │`
Change license 2020-12-28 01:18:44 +00:00			`│ Permission to use, copy, modify, and/or distribute this software for │`
			`│ any purpose with or without fee is hereby granted, provided that the │`
			`│ above copyright notice and this permission notice appear in all copies. │`
Initial import 2020-06-15 14:18:57 +00:00			`│ │`
Change license 2020-12-28 01:18:44 +00:00			`│ THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL │`
			`│ WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED │`
			`│ WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE │`
			`│ AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL │`
			`│ DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR │`
			`│ PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER │`
			`│ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR │`
			`│ PERFORMANCE OF THIS SOFTWARE. │`
Initial import 2020-06-15 14:18:57 +00:00			`╚─────────────────────────────────────────────────────────────────────────────*/`
Remove more nonstandard stuff from cosmopolitan.h Fixes #61 2021-03-01 07:42:35 +00:00			`#include "libc/macros.internal.h"`
Initial import 2020-06-15 14:18:57 +00:00
Get codebase completely working with LLVM You can now build Cosmopolitan with Clang: make -j8 MODE=llvm o/llvm/examples/hello.com The assembler and linker code is now friendly to LLVM too. So it's not needed to configure Clang to use binutils under the hood. If you love LLVM then you can now use pure LLVM. 2021-02-08 17:19:00 +00:00			`// Allocates uninitialized memory.`
			`//`
			`// Returns a pointer to a newly allocated chunk of at least n bytes, or`
			`// null if no space is available, in which case errno is set to ENOMEM`
			`// on ANSI C systems.`
			`//`
			`// If n is zero, malloc returns a minimum-sized chunk. (The minimum size`
			`// is 32 bytes on 64bit systems.) Note that size_t is an unsigned type,`
			`// so calls with arguments that would be negative if signed are`
			`// interpreted as requests for huge amounts of space, which will often`
			`// fail. The maximum supported value of n differs across systems, but is`
			`// in all cases less than the maximum representable value of a size_t.`
			`//`
Improve memory safety This commit makes numerous refinements to cosmopolitan memory handling. The default stack size has been reduced from 2mb to 128kb. A new macro is now provided so you can easily reconfigure the stack size to be any value you want. Work around the breaking change by adding to your main: STATIC_STACK_SIZE(0x00200000); // 2mb stack If you're not sure how much stack you need, then you can use: STATIC_YOINK("stack_usage_logging"); After which you can `sort -nr o/$MODE/stack.log`. Based on the unit test suite, nothing in the Cosmopolitan repository (except for Python) needs a stack size greater than 30kb. There are also new macros for detecting the size and address of the stack at runtime, e.g. GetStackAddr(). We also now support sigaltstack() so if you want to see nice looking crash reports whenever a stack overflow happens, you can put this in main(): ShowCrashReports(); Under `make MODE=dbg` and `make MODE=asan` the unit testing framework will now automatically print backtraces of memory allocations when things like memory leaks happen. Bugs are now fixed in ASAN global variable overrun detection. The memtrack and asan runtimes also handle edge cases now. The new tools helped to identify a few memory leaks, which are fixed by this change. This change should fix an issue reported in #288 with ARG_MAX limits. Fixing this doubled the performance of MKDEPS.COM and AR.COM yet again. 2021-10-14 00:27:13 +00:00			`// @param rdi is number of bytes needed, coerced to 1+`
Get codebase completely working with LLVM You can now build Cosmopolitan with Clang: make -j8 MODE=llvm o/llvm/examples/hello.com The assembler and linker code is now friendly to LLVM too. So it's not needed to configure Clang to use binutils under the hood. If you love LLVM then you can now use pure LLVM. 2021-02-08 17:19:00 +00:00			`// @return new memory, or NULL w/ errno`
Use re-entrant locks on stdio 2022-05-22 15:13:13 +00:00			`// @threadsafe`
Fix Clang support The amalgamated release is now confirmed to be working with Clang, including its integrated assembler. Fixes #41 2021-02-06 08:24:35 +00:00			`malloc: jmp *hook_malloc(%rip)`
Initial import 2020-06-15 14:18:57 +00:00			`.endfn malloc,globl`