Merge "Document FORTIFY."
diff --git a/libc/bionic/sysconf.cpp b/libc/bionic/sysconf.cpp
index 2442fd9..2b3200c 100644
--- a/libc/bionic/sysconf.cpp
+++ b/libc/bionic/sysconf.cpp
@@ -221,9 +221,7 @@
     case _SC_LEVEL4_CACHE_LINESIZE:   return 0;
 
     default:
-      // Posix says EINVAL is the only error that shall be returned,
-      // but glibc uses ENOSYS.
-      errno = ENOSYS;
+      errno = EINVAL;
       return -1;
   }
 }
diff --git a/libc/kernel/tools/generate_uapi_headers.sh b/libc/kernel/tools/generate_uapi_headers.sh
index 4603fbe..575da31 100755
--- a/libc/kernel/tools/generate_uapi_headers.sh
+++ b/libc/kernel/tools/generate_uapi_headers.sh
@@ -248,6 +248,9 @@
 copy_hdrs "${KERNEL_DIR}/${src_dir}/drivers/staging/android/uapi" \
           "${ANDROID_KERNEL_DIR}/uapi/linux" "no-copy-dirs"
 
+# Remove ion.h, it's not fully supported by the upstream kernel (see b/77976082).
+rm "${ANDROID_KERNEL_DIR}/uapi/linux/ion.h"
+
 # Copy the generated headers.
 copy_hdrs "${KERNEL_DIR}/${src_dir}/include/generated/uapi" \
           "${ANDROID_KERNEL_DIR}/uapi"
diff --git a/libc/kernel/uapi/linux/ion.h b/libc/kernel/uapi/linux/ion.h
deleted file mode 100644
index 7c9e6d7..0000000
--- a/libc/kernel/uapi/linux/ion.h
+++ /dev/null
@@ -1,59 +0,0 @@
-/****************************************************************************
- ****************************************************************************
- ***
- ***   This header was automatically generated from a Linux kernel header
- ***   of the same name, to make information necessary for userspace to
- ***   call into the kernel available to libc.  It contains only constants,
- ***   structures, and macros generated from the original header, and thus,
- ***   contains no copyrightable information.
- ***
- ***   To edit the content of this header, modify the corresponding
- ***   source file (e.g. under external/kernel-headers/original/) then
- ***   run bionic/libc/kernel/tools/update_all.py
- ***
- ***   Any manual change here will be lost the next time this script will
- ***   be run. You've been warned!
- ***
- ****************************************************************************
- ****************************************************************************/
-#ifndef _UAPI_LINUX_ION_H
-#define _UAPI_LINUX_ION_H
-#include <linux/ioctl.h>
-#include <linux/types.h>
-enum ion_heap_type {
-  ION_HEAP_TYPE_SYSTEM,
-  ION_HEAP_TYPE_SYSTEM_CONTIG,
-  ION_HEAP_TYPE_CARVEOUT,
-  ION_HEAP_TYPE_CHUNK,
-  ION_HEAP_TYPE_DMA,
-  ION_HEAP_TYPE_CUSTOM,
-};
-#define ION_NUM_HEAP_IDS (sizeof(unsigned int) * 8)
-#define ION_FLAG_CACHED 1
-struct ion_allocation_data {
-  __u64 len;
-  __u32 heap_id_mask;
-  __u32 flags;
-  __u32 fd;
-  __u32 unused;
-};
-#define MAX_HEAP_NAME 32
-struct ion_heap_data {
-  char name[MAX_HEAP_NAME];
-  __u32 type;
-  __u32 heap_id;
-  __u32 reserved0;
-  __u32 reserved1;
-  __u32 reserved2;
-};
-struct ion_heap_query {
-  __u32 cnt;
-  __u32 reserved0;
-  __u64 heaps;
-  __u32 reserved1;
-  __u32 reserved2;
-};
-#define ION_IOC_MAGIC 'I'
-#define ION_IOC_ALLOC _IOWR(ION_IOC_MAGIC, 0, struct ion_allocation_data)
-#define ION_IOC_HEAP_QUERY _IOWR(ION_IOC_MAGIC, 8, struct ion_heap_query)
-#endif
diff --git a/linker/linker_namespaces.h b/linker/linker_namespaces.h
index 03520d7..cd8b09d 100644
--- a/linker/linker_namespaces.h
+++ b/linker/linker_namespaces.h
@@ -54,6 +54,9 @@
   }
 
   bool is_accessible(const char* soname) const {
+    if (soname == nullptr) {
+      return false;
+    }
     return allow_all_shared_libs_ || shared_lib_sonames_.find(soname) != shared_lib_sonames_.end();
   }
 
diff --git a/tests/unistd_test.cpp b/tests/unistd_test.cpp
index db4859b..fd99455 100644
--- a/tests/unistd_test.cpp
+++ b/tests/unistd_test.cpp
@@ -836,19 +836,23 @@
 #endif // defined(__BIONIC__)
 }
 
-#define VERIFY_SYSCONF_UNSUPPORTED(name) VerifySysconf(name, #name, [](long v){return v == -1;})
+#define VERIFY_SYSCONF_UNKNOWN(name) \
+  VerifySysconf(name, #name, [](long v){return v == -1 && errno == EINVAL;})
+
+#define VERIFY_SYSCONF_UNSUPPORTED(name) \
+  VerifySysconf(name, #name, [](long v){return v == -1 && errno == 0;})
 
 // sysconf() means unlimited when it returns -1 with errno unchanged.
 #define VERIFY_SYSCONF_POSITIVE(name) \
-  VerifySysconf(name, #name, [](long v){return (v > 0 || v == -1);})
+  VerifySysconf(name, #name, [](long v){return (v > 0 || v == -1) && errno == 0;})
 
 #define VERIFY_SYSCONF_POSIX_VERSION(name) \
-  VerifySysconf(name, #name, [](long v){return v == _POSIX_VERSION;})
+  VerifySysconf(name, #name, [](long v){return v == _POSIX_VERSION && errno == 0;})
 
 static void VerifySysconf(int option, const char *option_name, bool (*verify)(long)) {
   errno = 0;
   long ret = sysconf(option);
-  EXPECT_TRUE(0 == errno && verify(ret)) << "name = " << option_name << ", ret = "
+  EXPECT_TRUE(verify(ret)) << "name = " << option_name << ", ret = "
       << ret <<", Error Message: " << strerror(errno);
 }
 
@@ -879,17 +883,17 @@
   VERIFY_SYSCONF_POSITIVE(_SC_RE_DUP_MAX);
   VERIFY_SYSCONF_POSITIVE(_SC_STREAM_MAX);
   VERIFY_SYSCONF_POSITIVE(_SC_TZNAME_MAX);
-  VerifySysconf(_SC_XOPEN_VERSION, "_SC_XOPEN_VERSION", [](long v){return v == _XOPEN_VERSION;});
+  VerifySysconf(_SC_XOPEN_VERSION, "_SC_XOPEN_VERSION", [](long v){return v == _XOPEN_VERSION && errno == 0;});
   VERIFY_SYSCONF_POSITIVE(_SC_ATEXIT_MAX);
   VERIFY_SYSCONF_POSITIVE(_SC_IOV_MAX);
   VERIFY_SYSCONF_POSITIVE(_SC_PAGESIZE);
   VERIFY_SYSCONF_POSITIVE(_SC_PAGE_SIZE);
   VerifySysconf(_SC_PAGE_SIZE, "_SC_PAGE_SIZE",
-                [](long v){return v == sysconf(_SC_PAGESIZE) && v == getpagesize();});
+                [](long v){return v == sysconf(_SC_PAGESIZE) && errno == 0 && v == getpagesize();});
   VERIFY_SYSCONF_POSITIVE(_SC_XOPEN_UNIX);
   VERIFY_SYSCONF_POSITIVE(_SC_AIO_LISTIO_MAX);
   VERIFY_SYSCONF_POSITIVE(_SC_AIO_MAX);
-  VerifySysconf(_SC_AIO_PRIO_DELTA_MAX, "_SC_AIO_PRIO_DELTA_MAX", [](long v){return v >= 0;});
+  VerifySysconf(_SC_AIO_PRIO_DELTA_MAX, "_SC_AIO_PRIO_DELTA_MAX", [](long v){return v >= 0 && errno == 0;});
   VERIFY_SYSCONF_POSITIVE(_SC_DELAYTIMER_MAX);
   VERIFY_SYSCONF_POSITIVE(_SC_MQ_OPEN_MAX);
   VERIFY_SYSCONF_POSITIVE(_SC_MQ_PRIO_MAX);
@@ -1024,6 +1028,11 @@
   ASSERT_EQ(ARG_MAX, sysconf(_SC_ARG_MAX));
 }
 
+TEST(UNISTD_TEST, sysconf_unknown) {
+  VERIFY_SYSCONF_UNKNOWN(-1);
+  VERIFY_SYSCONF_UNKNOWN(666);
+}
+
 TEST(UNISTD_TEST, dup2_same) {
   // POSIX says of dup2:
   // If fildes2 is already a valid open file descriptor ...