[v3] locale: align _nl_C_LC_CTYPE_class and _nl_C_LC_CTYPE_class32 arrays to uint16_t and uint32_t respectively

Message ID 20210401193723.1224640-1-yuanzi@google.com
State New
Headers show
Series
  • [v3] locale: align _nl_C_LC_CTYPE_class and _nl_C_LC_CTYPE_class32 arrays to uint16_t and uint32_t respectively
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Commit Message

Noah Goldstein via Libc-alpha April 1, 2021, 7:37 p.m.
steps to reproduce the problem: compile a program that uses ctype functions such as “isspace” for aarch64 with UBSan flag “-fsanitize=undefined” and run it on x86_64 machines with qemu user mode emulation.

observed behavior: UndefinedBehaviorSanitizer reports misaligned-pointer-use in the program.

solution: align the arrays defined in locale/C-ctype.c with correct data types as defined in ctype/ctype.h.

test suite regressions: none.
---
 locale/C-ctype.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

-- 
2.31.0.208.g409f899ff0-goog

Patch

diff --git a/locale/C-ctype.c b/locale/C-ctype.c
index bffdbedad0..da2c8cc33c 100644
--- a/locale/C-ctype.c
+++ b/locale/C-ctype.c
@@ -18,6 +18,7 @@ 
 
 #include "localeinfo.h"
 #include <endian.h>
+#include <stdalign.h>
 #include <stdint.h>
 
 #include "C-translit.h"
@@ -30,7 +31,7 @@ 
    In the `_nl_C_LC_CTYPE_class' array the value for EOF (== -1)
    is set to always return 0 and the conversion arrays return EOF.  */
 
-const char _nl_C_LC_CTYPE_class[768] attribute_hidden =
+alignas(uint16_t) const char _nl_C_LC_CTYPE_class[768] attribute_hidden =
   /* 0x80 */ "\000\000" "\000\000" "\000\000" "\000\000" "\000\000" "\000\000"
   /* 0x86 */ "\000\000" "\000\000" "\000\000" "\000\000" "\000\000" "\000\000"
   /* 0x8c */ "\000\000" "\000\000" "\000\000" "\000\000" "\000\000" "\000\000"
@@ -96,7 +97,7 @@  const char _nl_C_LC_CTYPE_class[768] attribute_hidden =
   /* 0xf4 */ "\000\000" "\000\000" "\000\000" "\000\000" "\000\000" "\000\000"
   /* 0xfa */ "\000\000" "\000\000" "\000\000" "\000\000" "\000\000" "\000\000"
 ;
-const char _nl_C_LC_CTYPE_class32[1024] attribute_hidden =
+alignas(uint32_t) const char _nl_C_LC_CTYPE_class32[1024] attribute_hidden =
   /* 0x00 */ "\000\000\002\000" "\000\000\002\000" "\000\000\002\000"
   /* 0x03 */ "\000\000\002\000" "\000\000\002\000" "\000\000\002\000"
   /* 0x06 */ "\000\000\002\000" "\000\000\002\000" "\000\000\002\000"