diff --git a/ndk/platforms/android-20/arch-arm/lib/libc.a b/ndk/platforms/android-20/arch-arm/lib/libc.a
index 0cf75d6be..2700ead1b 100644
Binary files a/ndk/platforms/android-20/arch-arm/lib/libc.a and b/ndk/platforms/android-20/arch-arm/lib/libc.a differ
diff --git a/ndk/platforms/android-20/arch-arm/lib/libm.a b/ndk/platforms/android-20/arch-arm/lib/libm.a
index bdeef8d71..13a88f521 100644
Binary files a/ndk/platforms/android-20/arch-arm/lib/libm.a and b/ndk/platforms/android-20/arch-arm/lib/libm.a differ
diff --git a/ndk/platforms/android-20/arch-arm/symbols/libc.so.functions.txt b/ndk/platforms/android-20/arch-arm/symbols/libc.so.functions.txt
index 6360fb23a..e1b84839d 100644
--- a/ndk/platforms/android-20/arch-arm/symbols/libc.so.functions.txt
+++ b/ndk/platforms/android-20/arch-arm/symbols/libc.so.functions.txt
@@ -748,7 +748,6 @@ isnormalf
 isnormall
 isprint
 ispunct
-issetugid
 isspace
 isupper
 iswalnum
diff --git a/ndk/platforms/android-20/arch-arm64/lib/libc.a b/ndk/platforms/android-20/arch-arm64/lib/libc.a
index e4e90cea6..297a6bb7c 100644
Binary files a/ndk/platforms/android-20/arch-arm64/lib/libc.a and b/ndk/platforms/android-20/arch-arm64/lib/libc.a differ
diff --git a/ndk/platforms/android-20/arch-arm64/lib/libm.a b/ndk/platforms/android-20/arch-arm64/lib/libm.a
index 69f5a00b0..fc0bf4458 100644
Binary files a/ndk/platforms/android-20/arch-arm64/lib/libm.a and b/ndk/platforms/android-20/arch-arm64/lib/libm.a differ
diff --git a/ndk/platforms/android-20/arch-arm64/lib/libz.a b/ndk/platforms/android-20/arch-arm64/lib/libz.a
index d8cc6a447..5ee579218 100644
Binary files a/ndk/platforms/android-20/arch-arm64/lib/libz.a and b/ndk/platforms/android-20/arch-arm64/lib/libz.a differ
diff --git a/ndk/platforms/android-20/arch-arm64/symbols/libc.so.functions.txt b/ndk/platforms/android-20/arch-arm64/symbols/libc.so.functions.txt
index 705590d28..e6c452bdd 100644
--- a/ndk/platforms/android-20/arch-arm64/symbols/libc.so.functions.txt
+++ b/ndk/platforms/android-20/arch-arm64/symbols/libc.so.functions.txt
@@ -581,7 +581,6 @@ isnormalf
 isnormall
 isprint
 ispunct
-issetugid
 isspace
 isupper
 iswalnum
diff --git a/ndk/platforms/android-20/arch-mips/lib/libc.a b/ndk/platforms/android-20/arch-mips/lib/libc.a
index 1719ecd9e..a4ffc8ebb 100644
Binary files a/ndk/platforms/android-20/arch-mips/lib/libc.a and b/ndk/platforms/android-20/arch-mips/lib/libc.a differ
diff --git a/ndk/platforms/android-20/arch-mips/lib/libm.a b/ndk/platforms/android-20/arch-mips/lib/libm.a
index cb1e71711..1a1782fe2 100644
Binary files a/ndk/platforms/android-20/arch-mips/lib/libm.a and b/ndk/platforms/android-20/arch-mips/lib/libm.a differ
diff --git a/ndk/platforms/android-20/arch-mips/lib/libz.a b/ndk/platforms/android-20/arch-mips/lib/libz.a
index 293d8969b..35ee3e287 100644
Binary files a/ndk/platforms/android-20/arch-mips/lib/libz.a and b/ndk/platforms/android-20/arch-mips/lib/libz.a differ
diff --git a/ndk/platforms/android-20/arch-mips/symbols/libc.so.functions.txt b/ndk/platforms/android-20/arch-mips/symbols/libc.so.functions.txt
index b89f15b9d..c7f4debdd 100644
--- a/ndk/platforms/android-20/arch-mips/symbols/libc.so.functions.txt
+++ b/ndk/platforms/android-20/arch-mips/symbols/libc.so.functions.txt
@@ -638,7 +638,6 @@ isnormalf
 isnormall
 isprint
 ispunct
-issetugid
 isspace
 isupper
 iswalnum
diff --git a/ndk/platforms/android-20/arch-mips64/lib/libc.a b/ndk/platforms/android-20/arch-mips64/lib/libc.a
index e0d989136..12d5f11fa 100644
Binary files a/ndk/platforms/android-20/arch-mips64/lib/libc.a and b/ndk/platforms/android-20/arch-mips64/lib/libc.a differ
diff --git a/ndk/platforms/android-20/arch-mips64/lib/libm.a b/ndk/platforms/android-20/arch-mips64/lib/libm.a
index c8e877ca8..21c390bdb 100644
Binary files a/ndk/platforms/android-20/arch-mips64/lib/libm.a and b/ndk/platforms/android-20/arch-mips64/lib/libm.a differ
diff --git a/ndk/platforms/android-20/arch-mips64/lib/libstdc++.a b/ndk/platforms/android-20/arch-mips64/lib/libstdc++.a
index aff84b9b1..33d8bd939 100644
Binary files a/ndk/platforms/android-20/arch-mips64/lib/libstdc++.a and b/ndk/platforms/android-20/arch-mips64/lib/libstdc++.a differ
diff --git a/ndk/platforms/android-20/arch-mips64/lib/libz.a b/ndk/platforms/android-20/arch-mips64/lib/libz.a
index d4a16dd4b..f9ca4866f 100644
Binary files a/ndk/platforms/android-20/arch-mips64/lib/libz.a and b/ndk/platforms/android-20/arch-mips64/lib/libz.a differ
diff --git a/ndk/platforms/android-20/arch-mips64/symbols/libc.so.functions.txt b/ndk/platforms/android-20/arch-mips64/symbols/libc.so.functions.txt
index 66b80a9bb..a8cec1d0e 100644
--- a/ndk/platforms/android-20/arch-mips64/symbols/libc.so.functions.txt
+++ b/ndk/platforms/android-20/arch-mips64/symbols/libc.so.functions.txt
@@ -585,7 +585,6 @@ isnormalf
 isnormall
 isprint
 ispunct
-issetugid
 isspace
 isupper
 iswalnum
diff --git a/ndk/platforms/android-20/arch-x86/lib/libc.a b/ndk/platforms/android-20/arch-x86/lib/libc.a
index ba9c1e82f..b6fe8e11a 100644
Binary files a/ndk/platforms/android-20/arch-x86/lib/libc.a and b/ndk/platforms/android-20/arch-x86/lib/libc.a differ
diff --git a/ndk/platforms/android-20/arch-x86/lib/libm.a b/ndk/platforms/android-20/arch-x86/lib/libm.a
index 4fc0cfb67..370a4efd6 100644
Binary files a/ndk/platforms/android-20/arch-x86/lib/libm.a and b/ndk/platforms/android-20/arch-x86/lib/libm.a differ
diff --git a/ndk/platforms/android-20/arch-x86/lib/libz.a b/ndk/platforms/android-20/arch-x86/lib/libz.a
index 824da0216..09166823f 100644
Binary files a/ndk/platforms/android-20/arch-x86/lib/libz.a and b/ndk/platforms/android-20/arch-x86/lib/libz.a differ
diff --git a/ndk/platforms/android-20/arch-x86/symbols/libc.so.functions.txt b/ndk/platforms/android-20/arch-x86/symbols/libc.so.functions.txt
index 7faaa45e1..735729ba9 100644
--- a/ndk/platforms/android-20/arch-x86/symbols/libc.so.functions.txt
+++ b/ndk/platforms/android-20/arch-x86/symbols/libc.so.functions.txt
@@ -634,7 +634,6 @@ isnormalf
 isnormall
 isprint
 ispunct
-issetugid
 isspace
 isupper
 iswalnum
diff --git a/ndk/platforms/android-20/arch-x86_64/lib64/libc.a b/ndk/platforms/android-20/arch-x86_64/lib64/libc.a
index 82ee862aa..90e031d27 100644
Binary files a/ndk/platforms/android-20/arch-x86_64/lib64/libc.a and b/ndk/platforms/android-20/arch-x86_64/lib64/libc.a differ
diff --git a/ndk/platforms/android-20/arch-x86_64/lib64/libm.a b/ndk/platforms/android-20/arch-x86_64/lib64/libm.a
index c039f4521..571eb3e57 100644
Binary files a/ndk/platforms/android-20/arch-x86_64/lib64/libm.a and b/ndk/platforms/android-20/arch-x86_64/lib64/libm.a differ
diff --git a/ndk/platforms/android-20/arch-x86_64/lib64/libz.a b/ndk/platforms/android-20/arch-x86_64/lib64/libz.a
index 591951239..536a06aa9 100644
Binary files a/ndk/platforms/android-20/arch-x86_64/lib64/libz.a and b/ndk/platforms/android-20/arch-x86_64/lib64/libz.a differ
diff --git a/ndk/platforms/android-20/arch-x86_64/symbols/libc.so.functions.txt b/ndk/platforms/android-20/arch-x86_64/symbols/libc.so.functions.txt
index 705590d28..e6c452bdd 100644
--- a/ndk/platforms/android-20/arch-x86_64/symbols/libc.so.functions.txt
+++ b/ndk/platforms/android-20/arch-x86_64/symbols/libc.so.functions.txt
@@ -581,7 +581,6 @@ isnormalf
 isnormall
 isprint
 ispunct
-issetugid
 isspace
 isupper
 iswalnum
diff --git a/ndk/platforms/android-20/include/stdint.h b/ndk/platforms/android-20/include/stdint.h
index f34843c09..9f588f737 100644
--- a/ndk/platforms/android-20/include/stdint.h
+++ b/ndk/platforms/android-20/include/stdint.h
@@ -180,6 +180,7 @@ typedef int64_t       intmax_t;
 #define INT_FAST32_MAX   INT32_MAX
 
 #define UINT32_MAX       (4294967295U)
+#define UINT32_MIN       (0)
 #define UINT_LEAST32_MAX UINT32_MAX
 #define UINT_FAST32_MAX  UINT32_MAX
 
diff --git a/ndk/platforms/android-20/include/sys/ucontext.h b/ndk/platforms/android-20/include/sys/ucontext.h
index d6c6b4317..f62380d8a 100644
--- a/ndk/platforms/android-20/include/sys/ucontext.h
+++ b/ndk/platforms/android-20/include/sys/ucontext.h
@@ -68,8 +68,13 @@ typedef struct ucontext {
   struct ucontext* uc_link;
   stack_t uc_stack;
   mcontext_t uc_mcontext;
-  sigset_t uc_sigmask;
-  char __padding[128 - sizeof(sigset_t)];
+  // Android has a wrong (smaller) sigset_t on ARM.
+  union {
+    sigset_t bionic;
+    uint32_t kernel[2];
+  } uc_sigmask;
+  // The kernel adds extra padding after uc_sigmask to match glibc sigset_t on ARM.
+  char __padding[120];
   unsigned long uc_regspace[128] __attribute__((__aligned__(8)));
 } ucontext_t;
 
@@ -83,6 +88,7 @@ typedef struct ucontext {
   struct ucontext *uc_link;
   stack_t uc_stack;
   sigset_t uc_sigmask;
+  // The kernel adds extra padding after uc_sigmask to match glibc sigset_t on ARM64.
   char __padding[128 - sizeof(sigset_t)];
   mcontext_t uc_mcontext;
 } ucontext_t;
@@ -146,8 +152,11 @@ typedef struct ucontext {
   struct ucontext* uc_link;
   stack_t uc_stack;
   mcontext_t uc_mcontext;
-  sigset_t uc_sigmask;
-  char __padding[128 - sizeof(sigset_t)];
+  // Android has a wrong (smaller) sigset_t on x86.
+  union {
+    sigset_t bionic;
+    uint32_t kernel[2];
+  } uc_sigmask;
   struct _libc_fpstate __fpregs_mem;
 } ucontext_t;
 
@@ -198,7 +207,6 @@ typedef struct ucontext {
   stack_t uc_stack;
   mcontext_t uc_mcontext;
   sigset_t uc_sigmask;
-  char __padding[128 - sizeof(sigset_t)];
 } ucontext_t;
 
 #elif defined(__mips64__)
@@ -275,7 +283,6 @@ typedef struct ucontext {
   stack_t uc_stack;
   mcontext_t uc_mcontext;
   sigset_t uc_sigmask;
-  char __padding[128 - sizeof(sigset_t)];
   struct _libc_fpstate __fpregs_mem;
 } ucontext_t;
 
diff --git a/ndk/platforms/android-20/include/unistd.h b/ndk/platforms/android-20/include/unistd.h
index 08a82e6ee..b4982cb0d 100644
--- a/ndk/platforms/android-20/include/unistd.h
+++ b/ndk/platforms/android-20/include/unistd.h
@@ -92,7 +92,6 @@ extern int setresuid(uid_t, uid_t, uid_t);
 extern int setresgid(gid_t, gid_t, gid_t);
 extern int getresuid(uid_t *ruid, uid_t *euid, uid_t *suid);
 extern int getresgid(gid_t *rgid, gid_t *egid, gid_t *sgid);
-extern int issetugid(void);
 extern char* getlogin(void);
 extern char* getusershell(void);
 extern void setusershell(void);