about summary refs log tree commit diff
path: root/sysdeps
diff options
context:
space:
mode:
authorSzabolcs Nagy <szabolcs.nagy@arm.com>2022-07-15 14:10:53 +0100
committerSzabolcs Nagy <szabolcs.nagy@arm.com>2022-08-05 19:45:19 +0100
commited90470cc02574d8a0f1aae6c38089b43cc6e5f6 (patch)
treeed0bc8282a3d3fff7bb1c72503d34a5ca9d02115 /sysdeps
parentd23dfc032415f04bd66598651afd5e70e696af07 (diff)
downloadglibc-ed90470cc02574d8a0f1aae6c38089b43cc6e5f6.tar.gz
glibc-ed90470cc02574d8a0f1aae6c38089b43cc6e5f6.tar.xz
glibc-ed90470cc02574d8a0f1aae6c38089b43cc6e5f6.zip
aarch64: morello: fix missing variadic argument in fcntl
In fcntl va_arg is currently used even if the caller did not pass
any variadic arguments. This is undefined behaviour and does not
work with the Morello purecap ABI, so use a helper macro.

When the argument is missing, the result of the helper macro is
arbitrary as it will be ignored by the kernel, we just have to
ensure it does not cause a runtime crash.
Diffstat (limited to 'sysdeps')
-rw-r--r--sysdeps/unix/sysv/linux/aarch64/morello/sysdep.h2
-rw-r--r--sysdeps/unix/sysv/linux/fcntl64.c6
-rw-r--r--sysdeps/unix/sysv/linux/fcntl_nocancel.c6
3 files changed, 12 insertions, 2 deletions
diff --git a/sysdeps/unix/sysv/linux/aarch64/morello/sysdep.h b/sysdeps/unix/sysv/linux/aarch64/morello/sysdep.h
index 5db89b096d..bad64a0674 100644
--- a/sysdeps/unix/sysv/linux/aarch64/morello/sysdep.h
+++ b/sysdeps/unix/sysv/linux/aarch64/morello/sysdep.h
@@ -105,6 +105,8 @@ typedef __intcap_t __sysarg_t;
   LOAD_ARGS_6 (c0, c1, c2, c3, c4, c5)		\
   register __sysarg_t _x6 asm ("c6") = _x6tmp;
 
+# define FCNTL_VA_ARG(a, t) (a ? va_arg(a, t) : 0)
+
 #endif	/* __ASSEMBLER__ */
 
 /* Disable pointer mangling for purecap ABI.  */
diff --git a/sysdeps/unix/sysv/linux/fcntl64.c b/sysdeps/unix/sysv/linux/fcntl64.c
index 5192b2d672..0b6afd3b59 100644
--- a/sysdeps/unix/sysv/linux/fcntl64.c
+++ b/sysdeps/unix/sysv/linux/fcntl64.c
@@ -29,6 +29,10 @@
 # define __NR_fcntl64 __NR_fcntl
 #endif
 
+#ifndef FCNTL_VA_ARG
+# define FCNTL_VA_ARG(a, t) va_arg(a, t)
+#endif
+
 #ifndef FCNTL_ADJUST_CMD
 # define FCNTL_ADJUST_CMD(__cmd) __cmd
 #endif
@@ -40,7 +44,7 @@ __libc_fcntl64 (int fd, int cmd, ...)
   void *arg;
 
   va_start (ap, cmd);
-  arg = va_arg (ap, void *);
+  arg = FCNTL_VA_ARG (ap, void *);
   va_end (ap);
 
   cmd = FCNTL_ADJUST_CMD (cmd);
diff --git a/sysdeps/unix/sysv/linux/fcntl_nocancel.c b/sysdeps/unix/sysv/linux/fcntl_nocancel.c
index 7c38e22399..f21b56d95b 100644
--- a/sysdeps/unix/sysv/linux/fcntl_nocancel.c
+++ b/sysdeps/unix/sysv/linux/fcntl_nocancel.c
@@ -26,6 +26,10 @@
 # define __NR_fcntl64 __NR_fcntl
 #endif
 
+#ifndef FCNTL_VA_ARG
+# define FCNTL_VA_ARG(a, t) va_arg(a, t)
+#endif
+
 #ifndef FCNTL_ADJUST_CMD
 # define FCNTL_ADJUST_CMD(__cmd) __cmd
 #endif
@@ -37,7 +41,7 @@ __fcntl64_nocancel (int fd, int cmd, ...)
   void *arg;
 
   va_start (ap, cmd);
-  arg = va_arg (ap, void *);
+  arg = FCNTL_VA_ARG (ap, void *);
   va_end (ap);
 
   cmd = FCNTL_ADJUST_CMD (cmd);