syscall: always use prlimit for getrlimit/setrlimit on Linux

Linux added the prlimit system call in version 2.6.36.
As our minimum Linux kernel version is now 3.2,
simplify the various getrlimit/setlrimit implementations
to just always use prlimit.

For #67001

Change-Id: I2512c21c947d0bc83f8f9077c143163fd8d83be3
Reviewed-on: https://go-review.googlesource.com/c/go/+/609178
Reviewed-by: Cherry Mui <cherryyz@google.com>
Reviewed-by: Damien Neil <dneil@google.com>
Auto-Submit: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Tobias Klauser <tobias.klauser@gmail.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>

1 files changed, 0 insertions, 30 deletions

diff --git a/src/syscall/syscall_linux_arm64.go b/src/syscall/syscall_linux_arm64.go
index b87b51c0c0..fb0ecd77b7 100644
--- a/src/syscall/syscall_linux_arm64.go
+++ b/src/syscall/syscall_linux_arm64.go
@@ -27,7 +27,6 @@ func Fstatat(fd int, path string, stat *Stat_t, flags int) error {
 //sysnb	Getegid() (egid int)
 //sysnb	Geteuid() (euid int)
 //sysnb	Getgid() (gid int)
-//sysnb	getrlimit(resource int, rlim *Rlimit) (err error)
 //sysnb	Getuid() (uid int)
 //sys	Listen(s int, n int) (err error)
 //sys	pread(fd int, p []byte, offset int64) (n int, err error) = SYS_PREAD64
@@ -37,7 +36,6 @@ func Fstatat(fd int, path string, stat *Stat_t, flags int) error {
 //sys	sendfile(outfd int, infd int, offset *int64, count int) (written int, err error)
 //sys	Setfsgid(gid int) (err error)
 //sys	Setfsuid(uid int) (err error)
-//sysnb	setrlimit1(resource int, rlim *Rlimit) (err error) = SYS_SETRLIMIT
 //sys	Shutdown(fd int, how int) (err error)
 //sys	Splice(rfd int, roff *int64, wfd int, woff *int64, len int, flags int) (n int64, err error)
 
@@ -140,34 +138,6 @@ func utimes(path string, tv *[2]Timeval) (err error) {
 	return utimensat(_AT_FDCWD, path, (*[2]Timespec)(unsafe.Pointer(&ts[0])), 0)
 }
 
-// Getrlimit prefers the prlimit64 system call. See issue 38604.
-func Getrlimit(resource int, rlim *Rlimit) error {
-	err := prlimit(0, resource, nil, rlim)
-	if err != ENOSYS {
-		return err
-	}
-	return getrlimit(resource, rlim)
-}
-
-// setrlimit prefers the prlimit64 system call. See issue 38604.
-func setrlimit(resource int, rlim *Rlimit) error {
-	err := prlimit(0, resource, rlim, nil)
-	if err != ENOSYS {
-		return err
-	}
-	return setrlimit1(resource, rlim)
-}
-
-//go:nosplit
-func rawSetrlimit(resource int, rlim *Rlimit) Errno {
-	_, _, errno := RawSyscall6(SYS_PRLIMIT64, 0, uintptr(resource), uintptr(unsafe.Pointer(rlim)), 0, 0, 0)
-	if errno != ENOSYS {
-		return errno
-	}
-	_, _, errno = RawSyscall(SYS_SETRLIMIT, uintptr(resource), uintptr(unsafe.Pointer(rlim)), 0)
-	return errno
-}
-
 func (r *PtraceRegs) PC() uint64 { return r.Pc }
 
 func (r *PtraceRegs) SetPC(pc uint64) { r.Pc = pc }