RIOT-OS/RIOT
RIOT-OS/RIOT
1
0
Fork 0
mirror of https://github.com/RIOT-OS/RIOT.git synced 2024-12-29 04:50:03 +01:00
Code Releases Activity

core: Fix undefined behaviour in C11 atomics

Browse Source 
Casting pointers to volatile memory to pointers to regular memory is permitted,
but using those pointers to access the memory results in undefined behavior.
This commit changes the casts to no longer drop the volatile qualifier.

References: https://en.cppreference.com/w/c/language/volatile
This commit is contained in:
Marian Buschsieweke 2019-05-15 14:31:01 +02:00
parent bf000a1fa5
commit 7749e621b8
No known key found for this signature in database
GPG Key ID: 61F64C6599B1539F
1 changed files with 22 additions and 22 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

44
core/atomic_c11.c
View File

@ -64,11 +64,11 @@ typedef uint64_t I8;
#define TEMPLATE_ATOMIC_LOAD_N(n) \
I##n __atomic_load_##n (const volatile void *ptr, int memorder) \
{ \
(void) memorder; \
unsigned int mask = irq_disable(); \
I##n old = *(I##n *)ptr; \
irq_restore(mask); \
return old; \
(void) memorder; \
unsigned int mask = irq_disable(); \
I##n old = *(const volatile I##n *)ptr; \
irq_restore(mask); \
return old; \
}
/**
@ -81,7 +81,7 @@ typedef uint64_t I8;
{ \
(void) memorder; \
unsigned int mask = irq_disable(); \
*(I##n *)ptr = val; \
*(volatile I##n *)ptr = val; \
irq_restore(mask); \
}
@ -95,8 +95,8 @@ typedef uint64_t I8;
{ \
(void) memorder; \
unsigned int mask = irq_disable(); \
I##n old = *(I##n *)ptr; \
*(I##n *)ptr = desired; \
I##n old = *(volatile I##n *)ptr; \
*(volatile I##n *)ptr = desired; \
irq_restore(mask); \
return old; \
}
@ -114,14 +114,14 @@ typedef uint64_t I8;
(void) success_memorder; \
(void) failure_memorder; \
unsigned int mask = irq_disable(); \
I##n cur = *(I##n *)ptr; \
I##n cur = *(volatile I##n *)ptr; \
if (cur != *(I##n *)expected) { \
*(I##n *)expected = cur; \
irq_restore(mask); \
return false; \
} \
\
*(I##n *)ptr = desired; \
*(volatile I##n *)ptr = desired; \
irq_restore(mask); \
return true; \
}
@ -137,12 +137,12 @@ typedef uint64_t I8;
#define TEMPLATE_ATOMIC_FETCH_OP_N(opname, op, n, prefixop) \
I##n __atomic_fetch_##opname##_##n(volatile void *ptr, I##n val, int memmodel) \
{ \
unsigned int mask = irq_disable(); \
(void)memmodel; \
I##n tmp = *(I##n *)ptr; \
*(I##n *)ptr = prefixop(tmp op val); \
irq_restore(mask); \
return tmp; \
unsigned int mask = irq_disable(); \
(void)memmodel; \
I##n tmp = *(volatile I##n *)ptr; \
*(volatile I##n *)ptr = prefixop(tmp op val); \
irq_restore(mask); \
return tmp; \
}
/**
@ -156,12 +156,12 @@ typedef uint64_t I8;
#define TEMPLATE_ATOMIC_OP_FETCH_N(opname, op, n, prefixop) \
I##n __atomic_##opname##_fetch_##n(volatile void *ptr, I##n val, int memmodel) \
{ \
(void)memmodel; \
unsigned int mask = irq_disable(); \
I##n tmp = prefixop((*(I##n *)ptr) op val); \
*(I##n *)ptr = tmp; \
irq_restore(mask); \
return tmp; \
(void)memmodel; \
unsigned int mask = irq_disable(); \
I##n tmp = prefixop((*(volatile I##n *)ptr) op val); \
*(volatile I##n *)ptr = tmp; \
irq_restore(mask); \
return tmp; \
}
/* Template instantiations below */