From e2cfb44540873fc0a566a8a119c550a64a38c319 Mon Sep 17 00:00:00 2001
From: Patrick Stewart <patrick@rfcreations.com>
Date: Thu, 14 Sep 2017 18:26:22 +0100
Subject: [PATCH] Revert "Assume prlimit64 is available."

This reverts commit 695d7d138eda449678a1650a8b8b58181033353f.
---
 sysdeps/unix/sysv/linux/getrlimit64.c     | 35 ++++++++++++++++++++++++++++++-
 sysdeps/unix/sysv/linux/kernel-features.h |  5 +++++
 sysdeps/unix/sysv/linux/prlimit.c         | 10 +++++++++
 sysdeps/unix/sysv/linux/setrlimit.c       |  7 ++++++-
 sysdeps/unix/sysv/linux/setrlimit64.c     | 31 ++++++++++++++++++++++++++-
 5 files changed, 85 insertions(+), 3 deletions(-)

diff --git a/sysdeps/unix/sysv/linux/getrlimit64.c b/sysdeps/unix/sysv/linux/getrlimit64.c
index 56af3c0646..37c173286f 100644
--- a/sysdeps/unix/sysv/linux/getrlimit64.c
+++ b/sysdeps/unix/sysv/linux/getrlimit64.c
@@ -35,7 +35,40 @@
 int
 __getrlimit64 (enum __rlimit_resource resource, struct rlimit64 *rlimits)
 {
-  return INLINE_SYSCALL_CALL (prlimit64, 0, resource, NULL, rlimits);
+#ifdef __NR_prlimit64
+  int res = INLINE_SYSCALL_CALL (prlimit64, 0, resource, NULL, rlimits);
+  if (res == 0 || errno != ENOSYS)
+    return res;
+#endif
+
+/* The fallback code only makes sense if the platform supports either
+   __NR_ugetrlimit and/or __NR_getrlimit.  */
+#if defined (__NR_ugetrlimit) || defined (__NR_getrlimit)
+# ifndef __NR_ugetrlimit
+#  define __NR_ugetrlimit __NR_getrlimit
+# endif
+# if __RLIM_T_MATCHES_RLIM64_T
+#  define rlimits32 (*rlimits)
+# else
+  struct rlimit rlimits32;
+# endif
+
+  if (INLINE_SYSCALL_CALL (ugetrlimit, resource, &rlimits32) < 0)
+    return -1;
+
+# if !__RLIM_T_MATCHES_RLIM64_T
+  if (rlimits32.rlim_cur == RLIM_INFINITY)
+    rlimits->rlim_cur = RLIM64_INFINITY;
+  else
+    rlimits->rlim_cur = rlimits32.rlim_cur;
+  if (rlimits32.rlim_max == RLIM_INFINITY)
+    rlimits->rlim_max = RLIM64_INFINITY;
+  else
+    rlimits->rlim_max = rlimits32.rlim_max;
+# endif /* !__RLIM_T_MATCHES_RLIM64_T */
+#endif /* defined (__NR_ugetrlimit) || defined (__NR_getrlimit)  */
+
+  return 0;
 }
 libc_hidden_def (__getrlimit64)
 
diff --git a/sysdeps/unix/sysv/linux/kernel-features.h b/sysdeps/unix/sysv/linux/kernel-features.h
index 9495db4fef..38788a75fb 100644
--- a/sysdeps/unix/sysv/linux/kernel-features.h
+++ b/sysdeps/unix/sysv/linux/kernel-features.h
@@ -81,6 +81,11 @@
 /* Support for sendmmsg functionality was added in 3.0.  */
 #define __ASSUME_SENDMMSG	1
 
+/* prlimit64 is available in 2.6.36.  */
+#if __LINUX_KERNEL_VERSION >= 0x020624
+# define __ASSUME_PRLIMIT64	1
+#endif
+
 /* On most architectures, most socket syscalls are supported for all
    supported kernel versions, but on some socketcall architectures
    separate syscalls were only added later.  */
diff --git a/sysdeps/unix/sysv/linux/prlimit.c b/sysdeps/unix/sysv/linux/prlimit.c
index d31980f10c..2996e73b81 100644
--- a/sysdeps/unix/sysv/linux/prlimit.c
+++ b/sysdeps/unix/sysv/linux/prlimit.c
@@ -20,6 +20,7 @@
 #include <sys/syscall.h>
 
 
+#ifdef __NR_prlimit64
 int
 prlimit (__pid_t pid, enum __rlimit_resource resource,
 	 const struct rlimit *new_rlimit, struct rlimit *old_rlimit)
@@ -72,3 +73,12 @@ prlimit (__pid_t pid, enum __rlimit_resource resource,
 
   return res;
 }
+#else
+int
+prlimit (__pid_t pid, enum __rlimit_resource resource,
+	 const struct rlimit *new_rlimit, struct rlimit *old_rlimit)
+{
+  return INLINE_SYSCALL_ERROR_RETURN_VALUE (ENOSYS);
+}
+stub_warning (prlimit)
+#endif
diff --git a/sysdeps/unix/sysv/linux/setrlimit.c b/sysdeps/unix/sysv/linux/setrlimit.c
index 8773c78236..01812ac355 100644
--- a/sysdeps/unix/sysv/linux/setrlimit.c
+++ b/sysdeps/unix/sysv/linux/setrlimit.c
@@ -34,6 +34,7 @@
 int
 __setrlimit (enum __rlimit_resource resource, const struct rlimit *rlim)
 {
+# ifdef __NR_prlimit64
   struct rlimit64 rlim64;
 
   if (rlim->rlim_cur == RLIM_INFINITY)
@@ -45,7 +46,11 @@ __setrlimit (enum __rlimit_resource resource, const struct rlimit *rlim)
   else
     rlim64.rlim_max = rlim->rlim_max;
 
-  return INLINE_SYSCALL_CALL (prlimit64, 0, resource, &rlim64, NULL);
+  int res = INLINE_SYSCALL_CALL (prlimit64, 0, resource, &rlim64, NULL);
+  if (res == 0 || errno != ENOSYS)
+    return res;
+# endif
+  return INLINE_SYSCALL_CALL (setrlimit, resource, rlim);
 }
 
 # if SHLIB_COMPAT (libc, GLIBC_2_0, GLIBC_2_2)
diff --git a/sysdeps/unix/sysv/linux/setrlimit64.c b/sysdeps/unix/sysv/linux/setrlimit64.c
index db1960fc18..2dd129d99e 100644
--- a/sysdeps/unix/sysv/linux/setrlimit64.c
+++ b/sysdeps/unix/sysv/linux/setrlimit64.c
@@ -36,7 +36,36 @@
 int
 __setrlimit64 (enum __rlimit_resource resource, const struct rlimit64 *rlimits)
 {
-  return INLINE_SYSCALL_CALL (prlimit64, 0, resource, rlimits, NULL);
+  int res;
+
+#ifdef __NR_prlimit64
+  res = INLINE_SYSCALL_CALL (prlimit64, 0, resource, rlimits, NULL);
+  if (res == 0 || errno != ENOSYS)
+    return res;
+#endif
+
+/* The fallback code only makes sense if the platform supports
+   __NR_setrlimit.  */
+#ifdef __NR_setrlimit
+# if !__RLIM_T_MATCHES_RLIM64_T
+  struct rlimit rlimits32;
+
+  if (rlimits->rlim_cur >= RLIM_INFINITY)
+    rlimits32.rlim_cur = RLIM_INFINITY;
+  else
+    rlimits32.rlim_cur = rlimits->rlim_cur;
+  if (rlimits->rlim_max >= RLIM_INFINITY)
+    rlimits32.rlim_max = RLIM_INFINITY;
+  else
+    rlimits32.rlim_max = rlimits->rlim_max;
+# else
+#  define rlimits32 (*rlimits)
+# endif
+
+  res = INLINE_SYSCALL_CALL (setrlimit, resource, &rlimits32);
+#endif
+
+  return res;
 }
 weak_alias (__setrlimit64, setrlimit64)
 
-- 
2.14.1