It was observed that getty crashes on RISC-V 64-bit target, with the
busybox binary compiled by clang/LLVM 17 with -O2. Not only getty,
but also some other applets like syslogd/vi are broken too.
Commit 5156b245 ("Make const ptr assign as function call in clang")
introduced XZALLOC_CONST_PTR() to defeat the compiler optimization,
however it only fixed a small number of broken places when compiling
busybox with clang/LLVM. A large number of places remain broken.
This commit renames existing ASSIGN_CONST_PTR() to _ASSIGN_CONST_PTR()
and makes the new ASSIGN_CONST_PTR() an out-of-line function to prevent
clang from reading pointer before it is assigned. With that, previous
XZALLOC_CONST_PTR() is no longer necessary and gets removed.
Signed-off-by: Bin Meng <[email protected]>
---
This commit supersedes previous one [1] as the fix is generic instead
of only fixing getty codes.
[1] https://lists.busybox.net/pipermail/busybox/2025-May/091486.html
coreutils/test.c | 2 +-
include/libbb.h | 10 +++++-----
libbb/const_hack.c | 4 ++--
libbb/lineedit.c | 2 +-
shell/ash.c | 6 +++---
5 files changed, 12 insertions(+), 12 deletions(-)
diff --git a/coreutils/test.c b/coreutils/test.c
index b63e33cc0..2cb396ef8 100644
--- a/coreutils/test.c
+++ b/coreutils/test.c
@@ -444,7 +444,7 @@ extern struct test_statics *BB_GLOBAL_CONST
test_ptr_to_statics;
#define leaving (S.leaving )
#define INIT_S() do { \
- XZALLOC_CONST_PTR(&test_ptr_to_statics, sizeof(S)); \
+ ASSIGN_CONST_PTR(&test_ptr_to_statics, xzalloc(sizeof(S))); \
} while (0)
#define DEINIT_S() do { \
free(test_ptr_to_statics); \
diff --git a/include/libbb.h b/include/libbb.h
index 558f3c627..6e44e0aec 100644
--- a/include/libbb.h
+++ b/include/libbb.h
@@ -2350,21 +2350,21 @@ static ALWAYS_INLINE void* not_const_pp(const void *p)
);
return pp;
}
-# define ASSIGN_CONST_PTR(pptr, v) do { \
+# define _ASSIGN_CONST_PTR(pptr, v) do { \
*(void**)not_const_pp(pptr) = (void*)(v); \
barrier(); \
} while (0)
-/* XZALLOC_CONST_PTR() is an out-of-line function to prevent
+/* ASSIGN_CONST_PTR() is an out-of-line function to prevent
* clang from reading pointer before it is assigned.
*/
-void XZALLOC_CONST_PTR(const void *pptr, size_t size) FAST_FUNC;
+void ASSIGN_CONST_PTR(const void *pptr, void *v) FAST_FUNC;
#else
-# define ASSIGN_CONST_PTR(pptr, v) do { \
+# define _ASSIGN_CONST_PTR(pptr, v) do { \
*(void**)(pptr) = (void*)(v); \
/* At least gcc 3.4.6 on mipsel needs optimization barrier */ \
barrier(); \
} while (0)
-# define XZALLOC_CONST_PTR(pptr, size) ASSIGN_CONST_PTR(pptr, xzalloc(size))
+# define ASSIGN_CONST_PTR(pptr, v) _ASSIGN_CONST_PTR(pptr, v)
#endif
#define SET_PTR_TO_GLOBALS(x) ASSIGN_CONST_PTR(&ptr_to_globals, x)
diff --git a/libbb/const_hack.c b/libbb/const_hack.c
index 9575e6d67..1568ac54d 100644
--- a/libbb/const_hack.c
+++ b/libbb/const_hack.c
@@ -9,8 +9,8 @@
#include "libbb.h"
#if defined(__clang_major__) && __clang_major__ >= 9
-void FAST_FUNC XZALLOC_CONST_PTR(const void *pptr, size_t size)
+void FAST_FUNC ASSIGN_CONST_PTR(const void *pptr, void *v)
{
- ASSIGN_CONST_PTR(pptr, xzalloc(size));
+ _ASSIGN_CONST_PTR(pptr, v);
}
#endif
diff --git a/libbb/lineedit.c b/libbb/lineedit.c
index 151208c1c..93fc88ea4 100644
--- a/libbb/lineedit.c
+++ b/libbb/lineedit.c
@@ -212,7 +212,7 @@ extern struct lineedit_statics *BB_GLOBAL_CONST
lineedit_ptr_to_statics;
#define delbuf (S.delbuf )
#define INIT_S() do { \
- XZALLOC_CONST_PTR(&lineedit_ptr_to_statics, sizeof(S)); \
+ ASSIGN_CONST_PTR(&lineedit_ptr_to_statics, xzalloc(sizeof(S))); \
} while (0)
static void deinit_S(void)
diff --git a/shell/ash.c b/shell/ash.c
index 9173b8608..d63de6f83 100644
--- a/shell/ash.c
+++ b/shell/ash.c
@@ -531,7 +531,7 @@ extern struct globals_misc *BB_GLOBAL_CONST
ash_ptr_to_globals_misc;
#define random_gen (G_misc.random_gen )
#define backgndpid (G_misc.backgndpid )
#define INIT_G_misc() do { \
- XZALLOC_CONST_PTR(&ash_ptr_to_globals_misc, sizeof(G_misc)); \
+ ASSIGN_CONST_PTR(&ash_ptr_to_globals_misc, xzalloc(sizeof(G_misc))); \
savestatus = -1; \
curdir = nullstr; \
physdir = nullstr; \
@@ -1612,7 +1612,7 @@ extern struct globals_memstack *BB_GLOBAL_CONST
ash_ptr_to_globals_memstack;
#define g_stacknleft (G_memstack.g_stacknleft)
#define stackbase (G_memstack.stackbase )
#define INIT_G_memstack() do { \
- XZALLOC_CONST_PTR(&ash_ptr_to_globals_memstack, sizeof(G_memstack)); \
+ ASSIGN_CONST_PTR(&ash_ptr_to_globals_memstack,
xzalloc(sizeof(G_memstack))); \
g_stackp = &stackbase; \
g_stacknxt = stackbase.space; \
g_stacknleft = MINSIZE; \
@@ -2242,7 +2242,7 @@ extern struct globals_var *BB_GLOBAL_CONST
ash_ptr_to_globals_var;
#endif
#define INIT_G_var() do { \
unsigned i; \
- XZALLOC_CONST_PTR(&ash_ptr_to_globals_var, sizeof(G_var)); \
+ ASSIGN_CONST_PTR(&ash_ptr_to_globals_var, xzalloc(sizeof(G_var))); \
for (i = 0; i < ARRAY_SIZE(varinit_data); i++) { \
varinit[i].flags = varinit_data[i].flags; \
varinit[i].var_text = varinit_data[i].var_text; \
--
2.34.1
_______________________________________________
busybox mailing list
[email protected]
https://lists.busybox.net/mailman/listinfo/busybox
