Remove wrong x32-specific lseek

Testing confirmed what I suspected: x32 lseek uses kernel-sized
(i.e. wide) long for offset parameter.

* file.c: Delete sys_lseek32.
* linux/syscall.h: Likewise.
* linux/x32/syscallent1.h: Likewise.
* test/x32_lseek.c: New file.

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

1 files changed, 38 insertions, 0 deletions

diff --git a/test/x32_lseek.c b/test/x32_lseek.c
new file mode 100644
index 0000000..6faa2fa
--- /dev/null
+++ b/test/x32_lseek.c
@@ -0,0 +1,38 @@
+// Test program which explores whether lseek syscall (not llseek!)
+// on x32 uses 64-bit offset argument.
+// IOW: does _kernel_ truncate it on entry?
+// The answer appears to be "no, full 64-bit offset is used".
+// strace must show it correctly too - tricky if strace itself is x32 one!
+//
+// Build: x86_64-gcc -static -Wall -ox32_lseek x32_lseek.c
+// Run:   $ strace ./x32_lseek 2>&1 | grep lseek | grep 1250999896321
+//        lseek(0, 1250999896321, SEEK_SET) = 1250999896321
+#define _GNU_SOURCE
+#include <sys/types.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <errno.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <stdio.h>
+#include <sys/syscall.h>
+// Ensure we are compiling to 64 bits
+struct bug { int t[sizeof(long) > 4 ? 1 : -1]; };
+int main(int argc, char **argv)
+{
+	long ofs = 0x12345678901;
+	errno = 0;
+	close(0);
+	if (open("/etc/passwd", O_RDONLY))
+		return 1;
+	long r = syscall(
+		(long) (__NR_lseek | 0x40000000), // make x32 call
+		(long) (0),
+		(long) (ofs),
+		(long) (SEEK_SET)
+	);
+	printf("pos:%ld(0x%lx) errno:%m\n", r, r);
+	if (!errno)
+		printf((r == ofs) ? "64-bit offset used\n" : "Kernel truncated offset\n");
+	return 0;
+}