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-rw-r--r--src/env/__init_security.c26
1 files changed, 26 insertions, 0 deletions
diff --git a/src/env/__init_security.c b/src/env/__init_security.c
new file mode 100644
index 00000000..5fd12ecb
--- /dev/null
+++ b/src/env/__init_security.c
@@ -0,0 +1,26 @@
+#include <stddef.h>
+#include <elf.h>
+#include <poll.h>
+#include <fcntl.h>
+#include "syscall.h"
+#include "libc.h"
+#include "atomic.h"
+
+#define AUX_CNT 24
+
+void __init_security(size_t *auxv)
+{
+ size_t i, aux[AUX_CNT] = { 0 };
+ struct pollfd pfd[3] = { {.fd=0}, {.fd=1}, {.fd=2} };
+
+ for (; auxv[0]; auxv+=2) if (auxv[0]<AUX_CNT) aux[auxv[0]] = auxv[1];
+ if (aux[AT_UID]==aux[AT_EUID] && aux[AT_GID]==aux[AT_EGID]
+ && !aux[AT_SECURE]) return;
+
+ __syscall(SYS_poll, pfd, 3, 0);
+ for (i=0; i<3; i++)
+ if (pfd[i].revents&POLLNVAL)
+ if (__syscall(SYS_open, "/dev/null", O_RDWR)<0)
+ a_crash();
+ libc.secure = 1;
+}