proc: support proc-empty-vm test on i386

Unmap everything starting from 4GB length until it unmaps, otherwise test
has to detect which virtual memory split kernel is using.

Link: https://lkml.kernel.org/r/20230630183434.17434-1-adobriyan@gmail.com
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Björn Töpel <bjorn@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
This commit is contained in:
Alexey Dobriyan 2023-06-30 21:34:33 +03:00 committed by Andrew Morton
parent 4099451ac2
commit 4356b11ec0
1 changed files with 16 additions and 0 deletions

View File

@ -37,6 +37,10 @@
#include <sys/wait.h>
#include <unistd.h>
#ifdef __amd64__
#define TEST_VSYSCALL
#endif
/*
* 0: vsyscall VMA doesn't exist vsyscall=none
* 1: vsyscall VMA is --xp vsyscall=xonly
@ -119,6 +123,7 @@ static void sigaction_SIGSEGV(int _, siginfo_t *__, void *___)
_exit(EXIT_FAILURE);
}
#ifdef TEST_VSYSCALL
static void sigaction_SIGSEGV_vsyscall(int _, siginfo_t *__, void *___)
{
_exit(g_vsyscall);
@ -170,6 +175,7 @@ static void vsyscall(void)
exit(1);
}
}
#endif
static int test_proc_pid_maps(pid_t pid)
{
@ -299,7 +305,9 @@ int main(void)
{
int rv = EXIT_SUCCESS;
#ifdef TEST_VSYSCALL
vsyscall();
#endif
switch (g_vsyscall) {
case 0:
@ -346,6 +354,14 @@ int main(void)
#ifdef __amd64__
munmap(NULL, ((size_t)1 << 47) - 4096);
#elif defined __i386__
{
size_t len;
for (len = -4096;; len -= 4096) {
munmap(NULL, len);
}
}
#else
#error "implement 'unmap everything'"
#endif