Changeset 133461c in mainline

Timestamp:

2023-10-22T17:49:28Z (13 months ago)

Author:

Jiří Zárevúcky <zarevucky.jiri@…>

Branches:

master, ticket/834-toolchain-update, topic/msim-upgrade, topic/simplify-dev-export

Children:

1c6c3e1d, cc73f6d4

Parents:

78f0422c

git-author:

Jiří Zárevúcky <zarevucky.jiri@…> (2023-10-22 17:44:39)

git-committer:

Jiří Zárevúcky <zarevucky.jiri@…> (2023-10-22 17:49:28)

Message:

Align arm32 atomic op prototypes with compiler's expectations

Based on a patch by @vhotspur, but without explicit casts
between pointer types. Those are evil footguns.

Files:

• kernel/arch/arm32/src/atomic.c (modified) (6 diffs)
• uspace/lib/c/arch/arm32/src/atomic.c (modified) (4 diffs)

kernel/arch/arm32/src/atomic.c

@@ -38 +38 @@
 #include <arch/asm.h>
 
-unsigned __atomic_fetch_add_4(volatile unsigned *mem, unsigned val, int model)
+unsigned __atomic_fetch_add_4(volatile void *mem0, unsigned val, int model)
 {
+        volatile unsigned *mem = mem0;
+
         /*
          * This implementation is for UP pre-ARMv6 systems where we do not have
@@ -51 +53 @@
 }
 
-unsigned __atomic_fetch_sub_4(volatile unsigned *mem, unsigned val, int model)
+unsigned __atomic_fetch_sub_4(volatile void *mem0, unsigned val, int model)
 {
+        volatile unsigned *mem = mem0;
+
         ipl_t ipl = interrupts_disable();
         unsigned ret = *mem;
@@ -67 +71 @@
  * returns the previous value of \a *ptr.
  */
-void *__sync_val_compare_and_swap_4(void **ptr, void *expected, void *new_val)
+unsigned __sync_val_compare_and_swap_4(volatile void *ptr0, unsigned expected,
+    unsigned new_val)
 {
+        volatile unsigned *ptr = ptr0;
+
         /*
          * Using an interrupt disabling spinlock might still lead to deadlock
@@ -78 +85 @@
         irq_spinlock_lock(&cas_lock, true);
 
-        void *cur_val = *ptr;
+        unsigned cur_val = *ptr;
 
         if (cur_val == expected) {
@@ -96 +103 @@
 /* Naive implementations of the newer intrinsics. */
 
-_Bool __atomic_compare_exchange_4(void **mem, void **expected, void *desired, _Bool weak, int success, int failure)
+_Bool __atomic_compare_exchange_4(volatile void *mem, void *expected0,
+    unsigned desired, _Bool weak, int success, int failure)
 {
+        unsigned *expected = expected0;
+
         (void) weak;
         (void) success;
         (void) failure;
 
-        void *old = *expected;
-        void *new = __sync_val_compare_and_swap_4(mem, old, desired);
+        unsigned old = *expected;
+        unsigned new = __sync_val_compare_and_swap_4(mem, old, desired);
         if (old == new) {
                 return 1;
@@ -112 +122 @@
 }
 
-void *__atomic_exchange_4(void **mem, void *val, int model)
+unsigned __atomic_exchange_4(volatile void *mem0, unsigned val, int model)
 {
+        volatile unsigned *mem = mem0;
+
         (void) model;
 
         irq_spinlock_lock(&cas_lock, true);
-        void *old = *mem;
+        unsigned old = *mem;
         *mem = val;
         irq_spinlock_unlock(&cas_lock, true);

uspace/lib/c/arch/arm32/src/atomic.c

@@ -38 +38 @@
 volatile unsigned *ras_page;
 
-bool __atomic_compare_exchange_4(volatile unsigned *mem, unsigned *expected, unsigned desired, bool weak, int success, int failure)
+bool __atomic_compare_exchange_4(volatile void *mem0, void *expected0,
+    unsigned desired, bool weak, int success, int failure)
 {
+        volatile unsigned *mem = mem0;
+        unsigned *expected = expected0;
+
         (void) success;
         (void) failure;
@@ -82 +86 @@
 }
 
-unsigned short __atomic_fetch_add_2(volatile unsigned short *mem, unsigned short val, int model)
+unsigned short __atomic_fetch_add_2(volatile void *mem0, unsigned short val,
+    int model)
 {
+        volatile unsigned short *mem = mem0;
+
         (void) model;
 
@@ -116 +123 @@
 }
 
-unsigned __atomic_fetch_add_4(volatile unsigned *mem, unsigned val, int model)
+unsigned __atomic_fetch_add_4(volatile void *mem0, unsigned val, int model)
 {
+        volatile unsigned *mem = mem0;
+
         (void) model;
 
@@ -150 +159 @@
 }
 
-unsigned __atomic_fetch_sub_4(volatile unsigned *mem, unsigned val, int model)
+unsigned __atomic_fetch_sub_4(volatile void *mem, unsigned val, int model)
 {
         return __atomic_fetch_add_4(mem, -val, model);