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add a detection of the Go runtime => zeroed heap only for Go apps

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This commit is contained in:
Stefan Lankes 2016-10-04 18:56:52 +02:00
parent a2819c6874
commit bcd7c83964
1 changed files with 13 additions and 1 deletions
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14
hermit/arch/x86/mm/page.c
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@ -88,6 +88,8 @@ static size_t * const other[PAGE_LEVELS] = {
};
#endif
static uint8_t expect_zeroed_pages = 0;
size_t virt_to_phys(size_t addr)
{
size_t vpn = addr >> PAGE_BITS; // virtual page number
@ -246,7 +248,7 @@ void page_fault_handler(struct state *s)
// on demand userspace heap mapping
viraddr &= PAGE_MASK;
size_t phyaddr = get_zeroed_page();
size_t phyaddr = expect_zeroed_pages ? get_zeroed_page() : get_page();
if (BUILTIN_EXPECT(!phyaddr, 0)) {
kprintf("out of memory: task = %u\n", task->id);
goto default_handler;
@ -289,8 +291,18 @@ default_handler:
sys_exit(-EFAULT);
}
// weak symbol is used to detect a Go application
void __attribute__((weak)) runtime_osinit();
int page_init(void)
{
// do we have Go application? => weak symbol isn't zeroe
// => Go expect zeroed pages => set zeroed_pages to true
if (runtime_osinit) {
expect_zeroed_pages = 1;
kputs("Detect Go runtime! Consequently, HermitCore zeroed heap.\n");
}
/* Replace default pagefault handler */
irq_uninstall_handler(14);
irq_install_handler(14, page_fault_handler);