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Rewrite memory manager

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Actually Portable Executable now supports Android. Cosmo's old mmap code
required a 47 bit address space. The new implementation is very agnostic
and supports both smaller address spaces (e.g. embedded) and even modern
56-bit PML5T paging for x86 which finally came true on Zen4 Threadripper

Cosmopolitan no longer requires UNIX systems to observe the Windows 64kb
granularity; i.e. sysconf(_SC_PAGE_SIZE) will now report the host native
page size. This fixes a longstanding POSIX conformance issue, concerning
file mappings that overlap the end of file. Other aspects of conformance
have been improved too, such as the subtleties of address assignment and
and the various subtleties surrounding MAP_FIXED and MAP_FIXED_NOREPLACE

On Windows, mappings larger than 100 megabytes won't be broken down into
thousands of independent 64kb mappings. Support for MAP_STACK is removed
by this change; please use NewCosmoStack() instead.

Stack overflow avoidance is now being implemented using the POSIX thread
APIs. Please use GetStackBottom() and GetStackAddr(), instead of the old
error-prone GetStackAddr() and HaveStackMemory() APIs which are removed.
This commit is contained in:
Justine Tunney 2024-06-20 20:46:42 -07:00
parent 7f6d0b8709
commit 6ffed14b9c
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GPG key ID: BE714B4575D6E328
150 changed files with 1893 additions and 5634 deletions
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34
libc/runtime/stack.h
View file

@ -14,17 +14,6 @@
*/
#define GetGuardSize() 16384
/**
* Align APE main thread stack at startup.
*
* You need this in your main program module:
*
* STATIC_STACK_ALIGN(GetStackSize());
*
* If you want to use GetStackAddr() and HaveStackMemory() safely on
* your main thread in your process. It causes crt.S to waste a tiny
* amount of memory to ensure those macros go extremely fast.
*/
#define STATIC_STACK_ALIGN(BYTES) \
_STACK_SYMBOL("ape_stack_align", _STACK_STRINGIFY(BYTES) _STACK_EXTRA)
@ -62,29 +51,12 @@ COSMOPOLITAN_C_START_
extern char ape_stack_prot[] __attribute__((__weak__));
extern char ape_stack_memsz[] __attribute__((__weak__));
extern char ape_stack_align[] __attribute__((__weak__));
extern char ape_stack_round[] __attribute__((__weak__));
/**
* Returns address of bottom of current stack.
*
* This always works on threads. If you want it to work on the main
* process too, then you'll need STATIC_STACK_ALIGN(GetStackSize())
* which will burn O(256kb) of memory to ensure thread invariants.
*/
#define GetStackAddr() ((GetStackPointer() - 1) & -GetStackSize())
uintptr_t GetStackBottom(void) pureconst;
#define GetStaticStackSize() ((uintptr_t)ape_stack_memsz)
/**
* Returns true if at least `n` bytes of stack are available.
*
* This always works on threads. If you want it to work on the main
* process too, then you'll need STATIC_STACK_ALIGN(GetStackSize())
* which will burn O(256kb) of memory to ensure thread invariants,
* which make this check exceedingly fast.
*/
#define HaveStackMemory(n) \
(GetStackPointer() >= GetStackAddr() + GetGuardSize() + (n))
/**
* Extends stack memory by poking large allocations.
*
@ -137,8 +109,6 @@ int FreeCosmoStack(void *) libcesque;
: "i"(ADDEND)); \
vAddr; \
})
#else
#define GetStaticStackAddr(ADDEND) (GetStackAddr() + ADDEND)
#endif
#define GetStackPointer() \