Implement PROT_GROWSDOWN

It fails with `/home/bjorn/.rustup/toolchains/stable-x86_64-unknown-linux-gnu/bin/rustc: error while loading shared libraries: libLLVM-15-rust-1.66.0-stable.so: cannot enable executable stack as shared object requires: Invalid argument`.

```
I2023-01-20T15:58:50.041212:blink/syscall.c:3594:256795 (sys) SysMprotect(0x4ffffffff000, 0x1000, 0x1000007, 0x70000022, 0x6fffffff, 0xeffffef5)
I2023-01-20T15:58:50.041216:blink/syscall.c:3740:256795 (sys) system call returned -1 Invalid argument
```

seems to be the syscall at fault.

Log

```
$ LD_LIBRARY_PATH=/home/bjorn/.rustup/toolchains/stable-x86_64-unknown-linux-gnu/lib o/opt/blink/blink ~/.rustup/toolchains/stable-x86_64-unknown-linux-gnu/bin/rustc -vV
I2023-01-20T15:58:50.028955:blink/syscall.c:3596:256795 (sys) SysBrk(0, 0x222ea2, 0x4d, 0x222ea2, 0x22ae88, 0x1c)
I2023-01-20T15:58:50.029007:blink/syscall.c:3740:256795 (sys) system call returned 6832128
I2023-01-20T15:58:50.029145:blink/syscall.c:3635:256795 (sys) SysUname(0x4fffffffeba0, 0x3b, 0xffffffffffffffc8, 0x6ffffe35, 0x400ba8, 0x70000022)
I2023-01-20T15:58:50.029153:blink/syscall.c:3740:256795 (sys) system call returned 0
I2023-01-20T15:58:50.029259:blink/syscall.c:3652:256795 (sys) SysReadlink(0x222a13, 0x4fffffffdbb0, 0x1000, 0x21e750, 0, 0x3f)
I2023-01-20T15:58:50.029282:blink/syscall.c:3740:256795 (sys) system call returned 44
I2023-01-20T15:58:50.029446:blink/syscall.c:3602:256795 (sys) SysAccess(0x225a40, 0x4, 0x2001c8, 0, 0x1, 0x4fffffffec58)
I2023-01-20T15:58:50.029454:blink/syscall.c:3740:256795 (sys) system call returned 0
I2023-01-20T15:58:50.029460:blink/syscall.c:3708:256795 (sys) SysOpenat(0xffffff9c, 0x225a40, 0x80000, 0, 0x80000, 0x225a40)
I2023-01-20T15:58:50.029462:blink/open.c:111:256795 (sys) Openat(/etc/ld.so.preload)
I2023-01-20T15:58:50.029468:blink/syscall.c:3740:256795 (sys) system call returned 4
I2023-01-20T15:58:50.029472:blink/syscall.c:3584:256795 (sys) SysFstat(0x4, 0x4fffffffec90, 0x4fffffffec90, 0, 0x1, 0x225a40)
I2023-01-20T15:58:50.029475:blink/syscall.c:3740:256795 (sys) system call returned 0
I2023-01-20T15:58:50.029478:blink/syscall.c:3582:256795 (sys) SysClose(0x4, 0, 0x4fffffffec90, 0, 0x1, 0x225a40)
I2023-01-20T15:58:50.029482:blink/syscall.c:3740:256795 (sys) system call returned 0
I2023-01-20T15:58:50.029552:blink/syscall.c:3708:256795 (sys) SysOpenat(0xffffff9c, 0x4fffffffe0f0, 0x80000, 0, 0x80000, 0x4fffffffe0f0)
I2023-01-20T15:58:50.029555:blink/open.c:111:256795 (sys) Openat(/home/bjorn/.rustup/toolchains/stable-x86_64-unknown-linux-gnu/lib/tls/x86_64/librustc_driver-105dc47ffbb49418.so)
I2023-01-20T15:58:50.029565:blink/open.c:118:256795 (sys) openat(/home/bjorn/.rustup/toolchains/stable-x86_64-unknown-linux-gnu/lib/tls/x86_64/librustc_driver-105dc47ffbb49418.so) failed: No such file or directory
I2023-01-20T15:58:50.029569:blink/syscall.c:3740:256795 (sys) system call returned -1 No such file or directory
I2023-01-20T15:58:50.029578:blink/syscall.c:3583:256795 (sys) SysStat(0x4fffffffe0f0, 0x4fffffffe1e0, 0x4fffffffe1e0, 0, 0x1, 0x4fffffffe0f0)
I2023-01-20T15:58:50.029583:blink/syscall.c:3740:256795 (sys) system call returned -1 No such file or directory
I2023-01-20T15:58:50.029594:blink/syscall.c:3708:256795 (sys) SysOpenat(0xffffff9c, 0x4fffffffe0f0, 0x80000, 0, 0x80000, 0x4fffffffe0f0)
I2023-01-20T15:58:50.029597:blink/open.c:111:256795 (sys) Openat(/home/bjorn/.rustup/toolchains/stable-x86_64-unknown-linux-gnu/lib/tls/librustc_driver-105dc47ffbb49418.so)
I2023-01-20T15:58:50.029602:blink/open.c:118:256795 (sys) openat(/home/bjorn/.rustup/toolchains/stable-x86_64-unknown-linux-gnu/lib/tls/librustc_driver-105dc47ffbb49418.so) failed: No such file or directory
I2023-01-20T15:58:50.029605:blink/syscall.c:3740:256795 (sys) system call returned -1 No such file or directory
I2023-01-20T15:58:50.029612:blink/syscall.c:3583:256795 (sys) SysStat(0x4fffffffe0f0, 0x4fffffffe1e0, 0x4fffffffe1e0, 0, 0x1, 0x4fffffffe0f0)
I2023-01-20T15:58:50.029616:blink/syscall.c:3740:256795 (sys) system call returned -1 No such file or directory
I2023-01-20T15:58:50.029625:blink/syscall.c:3708:256795 (sys) SysOpenat(0xffffff9c, 0x4fffffffe0f0, 0x80000, 0, 0x80000, 0x4fffffffe0f0)
I2023-01-20T15:58:50.029628:blink/open.c:111:256795 (sys) Openat(/home/bjorn/.rustup/toolchains/stable-x86_64-unknown-linux-gnu/lib/x86_64/librustc_driver-105dc47ffbb49418.so)
I2023-01-20T15:58:50.029633:blink/open.c:118:256795 (sys) openat(/home/bjorn/.rustup/toolchains/stable-x86_64-unknown-linux-gnu/lib/x86_64/librustc_driver-105dc47ffbb49418.so) failed: No such file or directory
I2023-01-20T15:58:50.029636:blink/syscall.c:3740:256795 (sys) system call returned -1 No such file or directory
I2023-01-20T15:58:50.029642:blink/syscall.c:3583:256795 (sys) SysStat(0x4fffffffe0f0, 0x4fffffffe1e0, 0x4fffffffe1e0, 0, 0x1, 0x4fffffffe0f0)
I2023-01-20T15:58:50.029647:blink/syscall.c:3740:256795 (sys) system call returned -1 No such file or directory
I2023-01-20T15:58:50.029655:blink/syscall.c:3708:256795 (sys) SysOpenat(0xffffff9c, 0x4fffffffe0f0, 0x80000, 0, 0x80000, 0x4fffffffe0f0)
I2023-01-20T15:58:50.029658:blink/open.c:111:256795 (sys) Openat(/home/bjorn/.rustup/toolchains/stable-x86_64-unknown-linux-gnu/lib/librustc_driver-105dc47ffbb49418.so)
I2023-01-20T15:58:50.029664:blink/syscall.c:3740:256795 (sys) system call returned 4
I2023-01-20T15:58:50.029669:blink/syscall.c:3579:256795 (sys) SysRead(0x4, 0x4fffffffe338, 0x340, 0, 0x80000, 0x4fffffffe0f0)
I2023-01-20T15:58:50.029675:blink/syscall.c:3740:256795 (sys) system call returned 832
I2023-01-20T15:58:50.029701:blink/syscall.c:3584:256795 (sys) SysFstat(0x4, 0x4fffffffe1e0, 0x4fffffffe1e0, 0, 0x1, 0x22c180)
I2023-01-20T15:58:50.029706:blink/syscall.c:3740:256795 (sys) system call returned 0
I2023-01-20T15:58:50.029723:blink/syscall.c:3588:256795 (sys) SysMmap(0, 0x2000, 0x3, 0x22, 0xffffffff, 0)
I2023-01-20T15:58:50.029740:blink/syscall.c:3740:256795 (sys) system call returned 35184372088832
I2023-01-20T15:58:50.029800:blink/syscall.c:3588:256795 (sys) SysMmap(0, 0x4118288, 0x1, 0x802, 0x4, 0)
I2023-01-20T15:58:50.030267:blink/syscall.c:3740:256795 (sys) system call returned 35184372097024
I2023-01-20T15:58:50.030277:blink/syscall.c:3588:256795 (sys) SysMmap(0x200001120000, 0x2df5000, 0x5, 0x812, 0x4, 0x111d000)
I2023-01-20T15:58:50.030655:blink/syscall.c:3740:256795 (sys) system call returned 35184390045696
I2023-01-20T15:58:50.030662:blink/syscall.c:3588:256795 (sys) SysMmap(0x200003f15000, 0x1f8000, 0x3, 0x812, 0x4, 0x3f11000)
I2023-01-20T15:58:50.030685:blink/syscall.c:3740:256795 (sys) system call returned 35184438235136
I2023-01-20T15:58:50.030690:blink/syscall.c:3588:256795 (sys) SysMmap(0x20000410d000, 0xa000, 0x3, 0x812, 0x4, 0x4108000)
I2023-01-20T15:58:50.030697:blink/syscall.c:3740:256795 (sys) system call returned 35184440299520
I2023-01-20T15:58:50.030722:blink/syscall.c:3588:256795 (sys) SysMmap(0x200004117000, 0x3288, 0x3, 0x32, 0xffffffff, 0)
I2023-01-20T15:58:50.030729:blink/syscall.c:3740:256795 (sys) system call returned 35184440340480
I2023-01-20T15:58:50.030761:blink/syscall.c:3582:256795 (sys) SysClose(0x4, 0x23, 0x2000040fcb30, 0x70000022, 0x6fffffff, 0xeffffef5)
I2023-01-20T15:58:50.030765:blink/syscall.c:3740:256795 (sys) system call returned 0
I2023-01-20T15:58:50.030850:blink/syscall.c:3708:256795 (sys) SysOpenat(0xffffff9c, 0x4fffffffe0d0, 0x80000, 0, 0x80000, 0x4fffffffe0d0)
I2023-01-20T15:58:50.030854:blink/open.c:111:256795 (sys) Openat(/home/bjorn/.rustup/toolchains/stable-x86_64-unknown-linux-gnu/lib/libstd-a11e3ca400b3ed09.so)
I2023-01-20T15:58:50.030863:blink/syscall.c:3740:256795 (sys) system call returned 4
I2023-01-20T15:58:50.030870:blink/syscall.c:3579:256795 (sys) SysRead(0x4, 0x4fffffffe318, 0x340, 0, 0x80000, 0x4fffffffe0d0)
I2023-01-20T15:58:50.030877:blink/syscall.c:3740:256795 (sys) system call returned 832
I2023-01-20T15:58:50.030906:blink/syscall.c:3584:256795 (sys) SysFstat(0x4, 0x4fffffffe1c0, 0x4fffffffe1c0, 0, 0x1, 0x22c180)
I2023-01-20T15:58:50.030911:blink/syscall.c:3740:256795 (sys) system call returned 0
I2023-01-20T15:58:50.030977:blink/syscall.c:3588:256795 (sys) SysMmap(0, 0x185620, 0x1, 0x802, 0x4, 0)
I2023-01-20T15:58:50.031003:blink/syscall.c:3740:256795 (sys) system call returned 35184440356864
I2023-01-20T15:58:50.031013:blink/syscall.c:3588:256795 (sys) SysMmap(0x2000041d1000, 0xc1000, 0x5, 0x812, 0x4, 0xb5000)
I2023-01-20T15:58:50.031030:blink/syscall.c:3740:256795 (sys) system call returned 35184441102336
I2023-01-20T15:58:50.031037:blink/syscall.c:3588:256795 (sys) SysMmap(0x200004292000, 0xe000, 0x3, 0x812, 0x4, 0x175000)
I2023-01-20T15:58:50.031045:blink/syscall.c:3740:256795 (sys) system call returned 35184441892864
I2023-01-20T15:58:50.031052:blink/syscall.c:3588:256795 (sys) SysMmap(0x2000042a0000, 0x1000, 0x3, 0x812, 0x4, 0x182000)
I2023-01-20T15:58:50.031058:blink/syscall.c:3740:256795 (sys) system call returned 35184441950208
I2023-01-20T15:58:50.031100:blink/syscall.c:3582:256795 (sys) SysClose(0x4, 0x23, 0x20000429e268, 0x70000022, 0x6fffffff, 0xeffffef5)
I2023-01-20T15:58:50.031104:blink/syscall.c:3740:256795 (sys) system call returned 0
I2023-01-20T15:58:50.031189:blink/syscall.c:3708:256795 (sys) SysOpenat(0xffffff9c, 0x4fffffffe0c0, 0x80000, 0, 0x80000, 0x4fffffffe0c0)
I2023-01-20T15:58:50.031193:blink/open.c:111:256795 (sys) Openat(/home/bjorn/.rustup/toolchains/stable-x86_64-unknown-linux-gnu/lib/libdl.so.2)
I2023-01-20T15:58:50.031201:blink/open.c:118:256795 (sys) openat(/home/bjorn/.rustup/toolchains/stable-x86_64-unknown-linux-gnu/lib/libdl.so.2) failed: No such file or directory
I2023-01-20T15:58:50.031204:blink/syscall.c:3740:256795 (sys) system call returned -1 No such file or directory
I2023-01-20T15:58:50.031228:blink/syscall.c:3708:256795 (sys) SysOpenat(0xffffff9c, 0x4fffffffe0c0, 0x80000, 0, 0x80000, 0x4fffffffe0c0)
I2023-01-20T15:58:50.031231:blink/open.c:111:256795 (sys) Openat(/home/bjorn/Projects/blink/o/opt/blink/../lib/tls/x86_64/libdl.so.2)
I2023-01-20T15:58:50.031239:blink/open.c:118:256795 (sys) openat(/home/bjorn/Projects/blink/o/opt/blink/../lib/tls/x86_64/libdl.so.2) failed: No such file or directory
I2023-01-20T15:58:50.031242:blink/syscall.c:3740:256795 (sys) system call returned -1 No such file or directory
I2023-01-20T15:58:50.031251:blink/syscall.c:3583:256795 (sys) SysStat(0x4fffffffe0c0, 0x4fffffffe1a0, 0x4fffffffe1a0, 0, 0x1, 0x4fffffffe0c0)
I2023-01-20T15:58:50.031257:blink/syscall.c:3740:256795 (sys) system call returned -1 No such file or directory
I2023-01-20T15:58:50.031268:blink/syscall.c:3708:256795 (sys) SysOpenat(0xffffff9c, 0x4fffffffe0c0, 0x80000, 0, 0x80000, 0x4fffffffe0c0)
I2023-01-20T15:58:50.031271:blink/open.c:111:256795 (sys) Openat(/home/bjorn/Projects/blink/o/opt/blink/../lib/tls/libdl.so.2)
I2023-01-20T15:58:50.031277:blink/open.c:118:256795 (sys) openat(/home/bjorn/Projects/blink/o/opt/blink/../lib/tls/libdl.so.2) failed: No such file or directory
I2023-01-20T15:58:50.031280:blink/syscall.c:3740:256795 (sys) system call returned -1 No such file or directory
I2023-01-20T15:58:50.031288:blink/syscall.c:3583:256795 (sys) SysStat(0x4fffffffe0c0, 0x4fffffffe1a0, 0x4fffffffe1a0, 0, 0x1, 0x4fffffffe0c0)
I2023-01-20T15:58:50.031293:blink/syscall.c:3740:256795 (sys) system call returned -1 No such file or directory
I2023-01-20T15:58:50.031303:blink/syscall.c:3708:256795 (sys) SysOpenat(0xffffff9c, 0x4fffffffe0c0, 0x80000, 0, 0x80000, 0x4fffffffe0c0)
I2023-01-20T15:58:50.031306:blink/open.c:111:256795 (sys) Openat(/home/bjorn/Projects/blink/o/opt/blink/../lib/x86_64/libdl.so.2)
I2023-01-20T15:58:50.031312:blink/open.c:118:256795 (sys) openat(/home/bjorn/Projects/blink/o/opt/blink/../lib/x86_64/libdl.so.2) failed: No such file or directory
I2023-01-20T15:58:50.031315:blink/syscall.c:3740:256795 (sys) system call returned -1 No such file or directory
I2023-01-20T15:58:50.031322:blink/syscall.c:3583:256795 (sys) SysStat(0x4fffffffe0c0, 0x4fffffffe1a0, 0x4fffffffe1a0, 0, 0x1, 0x4fffffffe0c0)
I2023-01-20T15:58:50.031328:blink/syscall.c:3740:256795 (sys) system call returned -1 No such file or directory
I2023-01-20T15:58:50.031337:blink/syscall.c:3708:256795 (sys) SysOpenat(0xffffff9c, 0x4fffffffe0c0, 0x80000, 0, 0x80000, 0x4fffffffe0c0)
I2023-01-20T15:58:50.031340:blink/open.c:111:256795 (sys) Openat(/home/bjorn/Projects/blink/o/opt/blink/../lib/libdl.so.2)
I2023-01-20T15:58:50.031346:blink/open.c:118:256795 (sys) openat(/home/bjorn/Projects/blink/o/opt/blink/../lib/libdl.so.2) failed: No such file or directory
I2023-01-20T15:58:50.031349:blink/syscall.c:3740:256795 (sys) system call returned -1 No such file or directory
I2023-01-20T15:58:50.031356:blink/syscall.c:3583:256795 (sys) SysStat(0x4fffffffe0c0, 0x4fffffffe1a0, 0x4fffffffe1a0, 0, 0x1, 0x4fffffffe0c0)
I2023-01-20T15:58:50.031361:blink/syscall.c:3740:256795 (sys) system call returned -1 No such file or directory
I2023-01-20T15:58:50.031374:blink/syscall.c:3708:256795 (sys) SysOpenat(0xffffff9c, 0x222be7, 0x80000, 0, 0x80000, 0x222be7)
I2023-01-20T15:58:50.031377:blink/open.c:111:256795 (sys) Openat(/etc/ld.so.cache)
I2023-01-20T15:58:50.031384:blink/syscall.c:3740:256795 (sys) system call returned 4
I2023-01-20T15:58:50.031389:blink/syscall.c:3584:256795 (sys) SysFstat(0x4, 0x4fffffffe150, 0x4fffffffe150, 0, 0x1, 0x222be7)
I2023-01-20T15:58:50.031394:blink/syscall.c:3740:256795 (sys) system call returned 0
I2023-01-20T15:58:50.031400:blink/syscall.c:3588:256795 (sys) SysMmap(0, 0x289ee, 0x1, 0x2, 0x4, 0)
I2023-01-20T15:58:50.031409:blink/syscall.c:3740:256795 (sys) system call returned 35184441954304
I2023-01-20T15:58:50.031413:blink/syscall.c:3582:256795 (sys) SysClose(0x4, 0x289ee, 0x1, 0x2, 0x4, 0)
I2023-01-20T15:58:50.031417:blink/syscall.c:3740:256795 (sys) system call returned 0
I2023-01-20T15:58:50.031507:blink/syscall.c:3708:256795 (sys) SysOpenat(0xffffff9c, 0x200000000ac0, 0x80000, 0, 0x80000, 0x200000000ac0)
I2023-01-20T15:58:50.031512:blink/open.c:111:256795 (sys) Openat(/lib/x86_64-linux-gnu/libdl.so.2)
I2023-01-20T15:58:50.031519:blink/syscall.c:3740:256795 (sys) system call returned 4
I2023-01-20T15:58:50.031525:blink/syscall.c:3579:256795 (sys) SysRead(0x4, 0x4fffffffe2f8, 0x340, 0, 0x80000, 0x200000000ac0)
I2023-01-20T15:58:50.031530:blink/syscall.c:3740:256795 (sys) system call returned 832
I2023-01-20T15:58:50.031558:blink/syscall.c:3584:256795 (sys) SysFstat(0x4, 0x4fffffffe1a0, 0x4fffffffe1a0, 0, 0x1, 0x22c180)
I2023-01-20T15:58:50.031562:blink/syscall.c:3740:256795 (sys) system call returned 0
I2023-01-20T15:58:50.031623:blink/syscall.c:3588:256795 (sys) SysMmap(0, 0x5110, 0x1, 0x802, 0x4, 0)
I2023-01-20T15:58:50.031631:blink/syscall.c:3740:256795 (sys) system call returned 35184442122240
I2023-01-20T15:58:50.031642:blink/syscall.c:3588:256795 (sys) SysMmap(0x2000042cb000, 0x2000, 0x5, 0x812, 0x4, 0x1000)
I2023-01-20T15:58:50.031655:blink/syscall.c:3740:256795 (sys) system call returned 35184442126336
I2023-01-20T15:58:50.031662:blink/syscall.c:3588:256795 (sys) SysMmap(0x2000042cd000, 0x1000, 0x1, 0x812, 0x4, 0x3000)
I2023-01-20T15:58:50.031671:blink/syscall.c:3740:256795 (sys) system call returned 35184442134528
I2023-01-20T15:58:50.031678:blink/syscall.c:3588:256795 (sys) SysMmap(0x2000042ce000, 0x2000, 0x3, 0x812, 0x4, 0x3000)
I2023-01-20T15:58:50.031685:blink/syscall.c:3740:256795 (sys) system call returned 35184442138624
I2023-01-20T15:58:50.031726:blink/syscall.c:3582:256795 (sys) SysClose(0x4, 0x29, 0, 0x70000022, 0x6fffffff, 0xeffffef5)
I2023-01-20T15:58:50.031730:blink/syscall.c:3740:256795 (sys) system call returned 0
I2023-01-20T15:58:50.031836:blink/syscall.c:3708:256795 (sys) SysOpenat(0xffffff9c, 0x4fffffffe0a0, 0x80000, 0, 0x80000, 0x4fffffffe0a0)
I2023-01-20T15:58:50.031840:blink/open.c:111:256795 (sys) Openat(/home/bjorn/.rustup/toolchains/stable-x86_64-unknown-linux-gnu/lib/librt.so.1)
I2023-01-20T15:58:50.031848:blink/open.c:118:256795 (sys) openat(/home/bjorn/.rustup/toolchains/stable-x86_64-unknown-linux-gnu/lib/librt.so.1) failed: No such file or directory
I2023-01-20T15:58:50.031851:blink/syscall.c:3740:256795 (sys) system call returned -1 No such file or directory
I2023-01-20T15:58:50.031926:blink/syscall.c:3708:256795 (sys) SysOpenat(0xffffff9c, 0x200000000fd0, 0x80000, 0, 0x80000, 0x200000000fd0)
I2023-01-20T15:58:50.031930:blink/open.c:111:256795 (sys) Openat(/lib/x86_64-linux-gnu/librt.so.1)
I2023-01-20T15:58:50.031935:blink/syscall.c:3740:256795 (sys) system call returned 4
I2023-01-20T15:58:50.031940:blink/syscall.c:3579:256795 (sys) SysRead(0x4, 0x4fffffffe2d8, 0x340, 0, 0x80000, 0x200000000fd0)
I2023-01-20T15:58:50.031945:blink/syscall.c:3740:256795 (sys) system call returned 832
I2023-01-20T15:58:50.031969:blink/syscall.c:3584:256795 (sys) SysFstat(0x4, 0x4fffffffe180, 0x4fffffffe180, 0, 0x1, 0x22c180)
I2023-01-20T15:58:50.031973:blink/syscall.c:3740:256795 (sys) system call returned 0
I2023-01-20T15:58:50.032034:blink/syscall.c:3588:256795 (sys) SysMmap(0, 0x9be0, 0x1, 0x802, 0x4, 0)
I2023-01-20T15:58:50.032041:blink/syscall.c:3740:256795 (sys) system call returned 35184442146816
I2023-01-20T15:58:50.032051:blink/syscall.c:3588:256795 (sys) SysMmap(0x2000042d2000, 0x4000, 0x5, 0x812, 0x4, 0x2000)
I2023-01-20T15:58:50.032062:blink/syscall.c:3740:256795 (sys) system call returned 35184442155008
I2023-01-20T15:58:50.032068:blink/syscall.c:3588:256795 (sys) SysMmap(0x2000042d6000, 0x2000, 0x1, 0x812, 0x4, 0x6000)
I2023-01-20T15:58:50.032075:blink/syscall.c:3740:256795 (sys) system call returned 35184442171392
I2023-01-20T15:58:50.032080:blink/syscall.c:3588:256795 (sys) SysMmap(0x2000042d8000, 0x2000, 0x3, 0x812, 0x4, 0x7000)
I2023-01-20T15:58:50.032086:blink/syscall.c:3740:256795 (sys) system call returned 35184442179584
I2023-01-20T15:58:50.032129:blink/syscall.c:3582:256795 (sys) SysClose(0x4, 0x29, 0x8, 0x70000022, 0x6fffffff, 0xeffffef5)
I2023-01-20T15:58:50.032133:blink/syscall.c:3740:256795 (sys) system call returned 0
I2023-01-20T15:58:50.032229:blink/syscall.c:3708:256795 (sys) SysOpenat(0xffffff9c, 0x4fffffffe080, 0x80000, 0, 0x80000, 0x4fffffffe080)
I2023-01-20T15:58:50.032233:blink/open.c:111:256795 (sys) Openat(/home/bjorn/.rustup/toolchains/stable-x86_64-unknown-linux-gnu/lib/libpthread.so.0)
I2023-01-20T15:58:50.032240:blink/open.c:118:256795 (sys) openat(/home/bjorn/.rustup/toolchains/stable-x86_64-unknown-linux-gnu/lib/libpthread.so.0) failed: No such file or directory
I2023-01-20T15:58:50.032244:blink/syscall.c:3740:256795 (sys) system call returned -1 No such file or directory
I2023-01-20T15:58:50.032333:blink/syscall.c:3708:256795 (sys) SysOpenat(0xffffff9c, 0x2000000014e0, 0x80000, 0, 0x80000, 0x2000000014e0)
I2023-01-20T15:58:50.032337:blink/open.c:111:256795 (sys) Openat(/lib/x86_64-linux-gnu/libpthread.so.0)
I2023-01-20T15:58:50.032346:blink/syscall.c:3740:256795 (sys) system call returned 4
I2023-01-20T15:58:50.032353:blink/syscall.c:3579:256795 (sys) SysRead(0x4, 0x4fffffffe2b8, 0x340, 0, 0x80000, 0x2000000014e0)
I2023-01-20T15:58:50.032359:blink/syscall.c:3740:256795 (sys) system call returned 832
I2023-01-20T15:58:50.032386:blink/syscall.c:3584:256795 (sys) SysFstat(0x4, 0x4fffffffe160, 0x4fffffffe160, 0, 0x1, 0x22c180)
I2023-01-20T15:58:50.032390:blink/syscall.c:3740:256795 (sys) system call returned 0
I2023-01-20T15:58:50.032451:blink/syscall.c:3588:256795 (sys) SysMmap(0, 0x21470, 0x1, 0x802, 0x4, 0)
I2023-01-20T15:58:50.032461:blink/syscall.c:3740:256795 (sys) system call returned 35184442187776
I2023-01-20T15:58:50.032470:blink/syscall.c:3588:256795 (sys) SysMmap(0x2000042e0000, 0x10000, 0x5, 0x812, 0x4, 0x6000)
I2023-01-20T15:58:50.032482:blink/syscall.c:3740:256795 (sys) system call returned 35184442212352
I2023-01-20T15:58:50.032489:blink/syscall.c:3588:256795 (sys) SysMmap(0x2000042f0000, 0x6000, 0x1, 0x812, 0x4, 0x16000)
I2023-01-20T15:58:50.032499:blink/syscall.c:3740:256795 (sys) system call returned 35184442277888
I2023-01-20T15:58:50.032505:blink/syscall.c:3588:256795 (sys) SysMmap(0x2000042f6000, 0x2000, 0x3, 0x812, 0x4, 0x1b000)
I2023-01-20T15:58:50.032513:blink/syscall.c:3740:256795 (sys) system call returned 35184442302464
I2023-01-20T15:58:50.032539:blink/syscall.c:3588:256795 (sys) SysMmap(0x2000042f8000, 0x3470, 0x3, 0x32, 0xffffffff, 0)
I2023-01-20T15:58:50.032546:blink/syscall.c:3740:256795 (sys) system call returned 35184442310656
I2023-01-20T15:58:50.032574:blink/syscall.c:3582:256795 (sys) SysClose(0x4, 0x29, 0x28, 0x70000022, 0x6fffffff, 0xeffffef5)
I2023-01-20T15:58:50.032578:blink/syscall.c:3740:256795 (sys) system call returned 0
I2023-01-20T15:58:50.032683:blink/syscall.c:3708:256795 (sys) SysOpenat(0xffffff9c, 0x4fffffffe070, 0x80000, 0, 0x80000, 0x4fffffffe070)
I2023-01-20T15:58:50.032687:blink/open.c:111:256795 (sys) Openat(/home/bjorn/.rustup/toolchains/stable-x86_64-unknown-linux-gnu/lib/libc.so.6)
I2023-01-20T15:58:50.032696:blink/open.c:118:256795 (sys) openat(/home/bjorn/.rustup/toolchains/stable-x86_64-unknown-linux-gnu/lib/libc.so.6) failed: No such file or directory
I2023-01-20T15:58:50.032699:blink/syscall.c:3740:256795 (sys) system call returned -1 No such file or directory
I2023-01-20T15:58:50.032767:blink/syscall.c:3708:256795 (sys) SysOpenat(0xffffff9c, 0x2000000019f0, 0x80000, 0, 0x80000, 0x2000000019f0)
I2023-01-20T15:58:50.032770:blink/open.c:111:256795 (sys) Openat(/lib/x86_64-linux-gnu/libc.so.6)
I2023-01-20T15:58:50.032778:blink/syscall.c:3740:256795 (sys) system call returned 4
I2023-01-20T15:58:50.032783:blink/syscall.c:3579:256795 (sys) SysRead(0x4, 0x4fffffffe298, 0x340, 0, 0x80000, 0x2000000019f0)
I2023-01-20T15:58:50.032788:blink/syscall.c:3740:256795 (sys) system call returned 832
I2023-01-20T15:58:50.032813:blink/syscall.c:3584:256795 (sys) SysFstat(0x4, 0x4fffffffe140, 0x4fffffffe140, 0, 0x1, 0x22c180)
I2023-01-20T15:58:50.032817:blink/syscall.c:3740:256795 (sys) system call returned 0
I2023-01-20T15:58:50.032877:blink/syscall.c:3588:256795 (sys) SysMmap(0, 0x1d4680, 0x1, 0x802, 0x4, 0)
I2023-01-20T15:58:50.032903:blink/syscall.c:3740:256795 (sys) system call returned 35184442327040
I2023-01-20T15:58:50.032911:blink/syscall.c:3588:256795 (sys) SysMmap(0x20000431e000, 0x15a000, 0x5, 0x812, 0x4, 0x22000)
I2023-01-20T15:58:50.032935:blink/syscall.c:3740:256795 (sys) system call returned 35184442466304
I2023-01-20T15:58:50.032941:blink/syscall.c:3588:256795 (sys) SysMmap(0x200004478000, 0x4f000, 0x1, 0x812, 0x4, 0x17c000)
I2023-01-20T15:58:50.032952:blink/syscall.c:3740:256795 (sys) system call returned 35184443883520
I2023-01-20T15:58:50.032957:blink/syscall.c:3588:256795 (sys) SysMmap(0x2000044c7000, 0x6000, 0x3, 0x812, 0x4, 0x1ca000)
I2023-01-20T15:58:50.032965:blink/syscall.c:3740:256795 (sys) system call returned 35184444207104
I2023-01-20T15:58:50.032986:blink/syscall.c:3588:256795 (sys) SysMmap(0x2000044cd000, 0x3680, 0x3, 0x32, 0xffffffff, 0)
I2023-01-20T15:58:50.032992:blink/syscall.c:3740:256795 (sys) system call returned 35184444231680
I2023-01-20T15:58:50.033019:blink/syscall.c:3582:256795 (sys) SysClose(0x4, 0x29, 0, 0x70000022, 0x6fffffff, 0xeffffef5)
I2023-01-20T15:58:50.033023:blink/syscall.c:3740:256795 (sys) system call returned 0
I2023-01-20T15:58:50.033198:blink/syscall.c:3708:256795 (sys) SysOpenat(0xffffff9c, 0x4fffffffe030, 0x80000, 0, 0x80000, 0x4fffffffe030)
I2023-01-20T15:58:50.033202:blink/open.c:111:256795 (sys) Openat(/home/bjorn/.rustup/toolchains/stable-x86_64-unknown-linux-gnu/lib/libLLVM-15-rust-1.66.0-stable.so)
I2023-01-20T15:58:50.033213:blink/syscall.c:3740:256795 (sys) system call returned 4
I2023-01-20T15:58:50.033218:blink/syscall.c:3579:256795 (sys) SysRead(0x4, 0x4fffffffe278, 0x340, 0, 0x80000, 0x4fffffffe030)
I2023-01-20T15:58:50.033224:blink/syscall.c:3740:256795 (sys) system call returned 832
I2023-01-20T15:58:50.033251:blink/syscall.c:3584:256795 (sys) SysFstat(0x4, 0x4fffffffe120, 0x4fffffffe120, 0, 0x1, 0x200000000000)
I2023-01-20T15:58:50.033255:blink/syscall.c:3740:256795 (sys) system call returned 0
I2023-01-20T15:58:50.033274:blink/syscall.c:3588:256795 (sys) SysMmap(0, 0x2000, 0x3, 0x22, 0xffffffff, 0)
I2023-01-20T15:58:50.033280:blink/syscall.c:3740:256795 (sys) system call returned 35184444248064
I2023-01-20T15:58:50.033340:blink/syscall.c:3588:256795 (sys) SysMmap(0, 0x6d2481c, 0x1, 0x802, 0x4, 0)
I2023-01-20T15:58:50.034055:blink/syscall.c:3740:256795 (sys) system call returned 35184444256256
I2023-01-20T15:58:50.034062:blink/syscall.c:3594:256795 (sys) SysMprotect(0x2000068b4000, 0x301f000, 0, 0x802, 0x4, 0)
I2023-01-20T15:58:50.040509:blink/syscall.c:3740:256795 (sys) system call returned 0
I2023-01-20T15:58:50.040523:blink/syscall.c:3588:256795 (sys) SysMmap(0x2000068b4000, 0x2a25000, 0x5, 0x812, 0x4, 0x23e0000)
I2023-01-20T15:58:50.040865:blink/syscall.c:3740:256795 (sys) system call returned 35184481878016
I2023-01-20T15:58:50.040872:blink/syscall.c:3588:256795 (sys) SysMmap(0x2000092d9000, 0x45c000, 0x3, 0x812, 0x4, 0x4e04000)
I2023-01-20T15:58:50.040913:blink/syscall.c:3740:256795 (sys) system call returned 35184526069760
I2023-01-20T15:58:50.040918:blink/syscall.c:3588:256795 (sys) SysMmap(0x200009735000, 0x41000, 0x3, 0x812, 0x4, 0x525f000)
I2023-01-20T15:58:50.040926:blink/syscall.c:3740:256795 (sys) system call returned 35184530640896
I2023-01-20T15:58:50.040955:blink/syscall.c:3588:256795 (sys) SysMmap(0x200009776000, 0x6eb89, 0x3, 0x32, 0xffffffff, 0)
I2023-01-20T15:58:50.040966:blink/syscall.c:3740:256795 (sys) system call returned 35184530907136
I2023-01-20T15:58:50.040971:blink/syscall.c:3588:256795 (sys) SysMmap(0x2000098d3000, 0x1925000, 0x5, 0x812, 0x4, 0x5400000)
I2023-01-20T15:58:50.041177:blink/syscall.c:3740:256795 (sys) system call returned 35184532336640
I2023-01-20T15:58:50.041212:blink/syscall.c:3594:256795 (sys) SysMprotect(0x4ffffffff000, 0x1000, 0x1000007, 0x70000022, 0x6fffffff, 0xeffffef5)
I2023-01-20T15:58:50.041216:blink/syscall.c:3740:256795 (sys) system call returned -1 Invalid argument
I2023-01-20T15:58:50.041224:blink/syscall.c:3582:256795 (sys) SysClose(0x4, 0x4, 0x200000244d93, 0x70000022, 0x2000044d1000, 0x2242d8)
I2023-01-20T15:58:50.041227:blink/syscall.c:3740:256795 (sys) system call returned 0
I2023-01-20T15:58:50.041347:blink/syscall.c:3601:256795 (sys) SysWritev(0x2, 0x4fffffffddb0, 0xa, 0, 0x40, 0xffffffff)
/home/bjorn/.rustup/toolchains/stable-x86_64-unknown-linux-gnu/bin/rustc: error while loading shared libraries: libLLVM-15-rust-1.66.0-stable.so: cannot enable executable stack as shared object requires: Invalid argument
I2023-01-20T15:58:50.041355:blink/syscall.c:3740:256795 (sys) system call returned 221
```

Start in syscall.c around the logged SysMprotect call and trace how its protection flags are handled. Reproduce the reported rustc command and verify that implementing PROT_GROWSDOWN prevents the Invalid argument failure.

Written by the indexing model from the issue text.