libk  Artifact [ae0ed8cd11]

Artifact ae0ed8cd11ad2b05ae0cd108dd14bc3bfcf355f5525e8c2f7854d47b648bb854:

  • File mod/kcore/testbin.exe.c — part of check-in [e50a476efe] at 2019-08-22 02:52:20 on branch trunk — removed sneaky segfault in x86-64 syscall fn where %r8 (the register that contains the pointer to the syscall arguments from the C syscall wrapper, which need to be copied into the correct registers before the kernel is invoked) gets overwritten if the syscall valency > 5, because of overlapping ccall and syscall ABI argument registers - r8 is clobbered by argument 5 and any further attempts to use it as a ptr segfault at best. also modified the report function so that it immediate cancels compilation if a sub-process reports failure. changed allocator function signatures so they can return a condition code if the kernel reports an error; updated example code so it compiles and runs without fault. (user: lexi, size: 557) [annotate] [blame] [check-ins using]

#include <k/core.h>
#include <k/mem.h>
#include <k/io.h>
#include <k/magic.h>

struct object {
	u8 a;
	s16 b;
	bool c;

stat_long entry(kenv e) {
	const char msg[] = "hello from libk\n";
	ksraw ptr = { Kmsz(msg), msg };

	bool maybe = true;
	maybe = no;

	if (kiosend(e.std, ptr, null) == kiocond_ok) {
		/* great, continue */
	} else {
		return kbad_io;

	void* region;
	kmcond alloc = kmheapa(&region, 2048);
	if (alloc != kmcond_ok) return kbad_mem;


	if (kmheapf(region) >= kmcond_fail) return kbad_mem;

	return kbad_ok;