RGBCube/serenity
1
Fork 0
mirror of https://github.com/RGBCube/serenity synced 2025-07-27 04:47:35 +00:00
Code Issues Activity Actions

Support basic mmap'ing of a file!

Browse source 
All right, we can now mmap() a file and it gets magically paged in from fs
in response to an NP page fault. This is really cool :^)

I need to refactor this to support sharing of read-only file-backed pages,
but it's cool to just have something working.
This commit is contained in:
Andreas Kling 2018-11-08 12:59:16 +01:00
parent fdbd9f1e27
commit 3c8064a787
8 changed files with 141 additions and 14 deletions
Download patch file Download diff file Expand all files Collapse all files

31
Userland/sh.cpp
View file

@ -6,6 +6,7 @@
#include <LibC/stdlib.h>
#include <LibC/utsname.h>
#include <LibC/pwd.h>
#include <sys/mman.h>
#include <signal.h>
#include <AK/FileSystemPath.h>
@ -112,6 +113,32 @@ static int sh_wt(int, const char**)
return 0;
}
static int sh_mf(int, const char**)
{
int rc;
int fd = open("/Banner.txt", O_RDONLY);
if (fd < 0) {
perror("open(/Banner.txt)");
return 1;
}
printf("opened /Banner.txt, calling mmap...\n");
byte* data = (byte*)mmap(nullptr, getpagesize(), PROT_READ, MAP_PRIVATE, fd, 0);
if (data == MAP_FAILED) {
perror("mmap()");
goto close_it;
}
printf("mapped file @ %p\n", data);
printf("contents: %b %b %b %b\n", data[0], data[1], data[2], data[3]);
rc = munmap(data, getpagesize());
printf("munmap() returned %d\n", rc);
close_it:
rc = close(fd);
printf("close() returned %d\n", rc);
return 0;
}
static int sh_exit(int, const char**)
{
printf("Good-bye!\n");
@ -190,6 +217,10 @@ static bool handle_builtin(int argc, const char** argv, int& retval)
retval = sh_wt(argc, argv);
return true;
}
if (!strcmp(argv[0], "mf")) {
retval = sh_mf(argc, argv);
return true;
}
if (!strcmp(argv[0], "fork")) {
retval = sh_fork(argc, argv);
return true;