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cosmopolitan/libc/sysv/consts/ss.h

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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
#ifndef COSMOPOLITAN_LIBC_SYSV_CONSTS_SS_H_
#define COSMOPOLITAN_LIBC_SYSV_CONSTS_SS_H_
COSMOPOLITAN_C_START_
Change magnum types to match other platforms (#525)
2022-08-05 21:50:08 +00:00
extern const int SS_DISABLE;
Make improvements - Every unit test now passes on Apple Silicon. The final piece of this puzzle was porting our POSIX threads cancelation support, since that works differently on ARM64 XNU vs. AMD64. Our semaphore support on Apple Silicon is also superior now compared to AMD64, thanks to the grand central dispatch library which lets *NSYNC locks go faster. - The Cosmopolitan runtime is now more stable, particularly on Windows. To do this, thread local storage is mandatory at all runtime levels, and the innermost packages of the C library is no longer being built using ASAN. TLS is being bootstrapped with a 128-byte TIB during the process startup phase, and then later on the runtime re-allocates it either statically or dynamically to support code using _Thread_local. fork() and execve() now do a better job cooperating with threads. We can now check how much stack memory is left in the process or thread when functions like kprintf() / execve() etc. call alloca(), so that ENOMEM can be raised, reduce a buffer size, or just print a warning. - POSIX signal emulation is now implemented the same way kernels do it with pthread_kill() and raise(). Any thread can interrupt any other thread, regardless of what it's doing. If it's blocked on read/write then the killer thread will cancel its i/o operation so that EINTR can be returned in the mark thread immediately. If it's doing a tight CPU bound operation, then that's also interrupted by the signal delivery. Signal delivery works now by suspending a thread and pushing context data structures onto its stack, and redirecting its execution to a trampoline function, which calls SetThreadContext(GetCurrentThread()) when it's done. - We're now doing a better job managing locks and handles. On NetBSD we now close semaphore file descriptors in forked children. Semaphores on Windows can now be canceled immediately, which means mutexes/condition variables will now go faster. Apple Silicon semaphores can be canceled too. We're now using Apple's pthread_yield() funciton. Apple _nocancel syscalls are now used on XNU when appropriate to ensure pthread_cancel requests aren't lost. The MbedTLS library has been updated to support POSIX thread cancelations. See tool/build/runitd.c for an example of how it can be used for production multi-threaded tls servers. Handles on Windows now leak less often across processes. All i/o operations on Windows are now overlapped, which means file pointers can no longer be inherited across dup() and fork() for the time being. - We now spawn a thread on Windows to deliver SIGCHLD and wakeup wait4() which means, for example, that posix_spawn() now goes 3x faster. POSIX spawn is also now more correct. Like Musl, it's now able to report the failure code of execve() via a pipe although our approach favors using shared memory to do that on systems that have a true vfork() function. - We now spawn a thread to deliver SIGALRM to threads when setitimer() is used. This enables the most precise wakeups the OS makes possible. - The Cosmopolitan runtime now uses less memory. On NetBSD for example, it turned out the kernel would actually commit the PT_GNU_STACK size which caused RSS to be 6mb for every process. Now it's down to ~4kb. On Apple Silicon, we reduce the mandatory upstream thread size to the smallest possible size to reduce the memory overhead of Cosmo threads. The examples directory has a program called greenbean which can spawn a web server on Linux with 10,000 worker threads and have the memory usage of the process be ~77mb. The 1024 byte overhead of POSIX-style thread-local storage is now optional; it won't be allocated until the pthread_setspecific/getspecific functions are called. On Windows, the threads that get spawned which are internal to the libc implementation use reserve rather than commit memory, which shaves a few hundred kb. - sigaltstack() is now supported on Windows, however it's currently not able to be used to handle stack overflows, since crash signals are still generated by WIN32. However the crash handler will still switch to the alt stack, which is helpful in environments with tiny threads. - Test binaries are now smaller. Many of the mandatory dependencies of the test runner have been removed. This ensures many programs can do a better job only linking the the thing they're testing. This caused the test binaries for LIBC_FMT for example, to decrease from 200kb to 50kb - long double is no longer used in the implementation details of libc, except in the APIs that define it. The old code that used long double for time (instead of struct timespec) has now been thoroughly removed. - ShowCrashReports() is now much tinier in MODE=tiny. Instead of doing backtraces itself, it'll just print a command you can run on the shell using our new `cosmoaddr2line` program to view the backtrace. - Crash report signal handling now works in a much better way. Instead of terminating the process, it now relies on SA_RESETHAND so that the default SIG_IGN behavior can terminate the process if necessary. - Our pledge() functionality has now been fully ported to AARCH64 Linux.
2023-09-19 03:44:45 +00:00
extern const int _SIGSTKSZ;
extern const int _MINSIGSTKSZ;
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
COSMOPOLITAN_C_END_
Improve memory manager and signal handling On Windows, mmap() now chooses addresses transactionally. It reduces the risk of badness when interacting with the WIN32 memory manager. We don't throw darts anymore. There is also no more retry limit, since we recover from mystery maps more gracefully. The subroutine for combining adjacent maps has been rewritten for clarity. The print maps subroutine is better This change goes to great lengths to perfect the stack overflow code. On Windows you can now longjmp() out of a crash signal handler. Guard pages previously weren't being restored properly by the signal handler. That's fixed, so on Windows you can now handle a stack overflow multiple times. Great thought has been put into selecting the perfect SIGSTKSZ constants so you can save sigaltstack() memory. You can now use kprintf() with 512 bytes of stack available. The guard pages beneath the main stack are now recorded in the memory manager. This change fixes getcontext() so it works right with the %rax register.
2024-12-27 09:03:11 +00:00
#define SIGSTKSZ 32768 /* just itself believed to be safe */
Fix corner case in Linux stack mappings We need to make sure no existing mappings exist between the MAP_GROWSDOWN page and the guard page, since otherwise it's not going to be able to grow down thus causing difficult to troubleshoot failures.
2022-10-03 20:43:52 +00:00
#define MINSIGSTKSZ 32768 /* xnu defines the highest minimum */
Write tests for new APE loader and fix bugs - Add FreeBSD-specific mmap() flags - Reduce size of the APE loader from 8kb to 4kb - Work towards fixing the Makefile build on WSL - Automate testing of APE no-modify-self behaviors - Make the ape.S shell script code cleaner and tinier - Improve the APE sanity check to test behavior better - Fixed issue with ShowCrashReports() sigaltstack() on BSDs - Delete symbols for S_MODE magnums which wasted compile time If you checked out yesterday's APE commit, please run: rm -f /usr/bin/ape o/tmp/ape /tmp/ape "${TMPDIR:-/tmp}/ape" Because this change fixes certain aspects of the new ABI. We don't have automated migrations for APE loader versions yet. Thanks! You can also download prebuilt binaries here: - https://justine.lol/ape.elf (Linux/FreeBSD/NetBSD/OpenBSD) - https://justine.lol/ape.macho (Apple) Install the appropriate one as `/usr/bin/ape`.
2022-05-22 11:51:02 +00:00
#define SS_ONSTACK 1
#define SS_DISABLE SS_DISABLE
Improve memory safety This commit makes numerous refinements to cosmopolitan memory handling. The default stack size has been reduced from 2mb to 128kb. A new macro is now provided so you can easily reconfigure the stack size to be any value you want. Work around the breaking change by adding to your main: STATIC_STACK_SIZE(0x00200000); // 2mb stack If you're not sure how much stack you need, then you can use: STATIC_YOINK("stack_usage_logging"); After which you can `sort -nr o/$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
#endif /* COSMOPOLITAN_LIBC_SYSV_CONSTS_SS_H_ */
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