xen: use DECLARE_BOUNDS as required

Use DECLARE_BOUNDS and the two static inline functions that come with it
for comparisons and subtractions of:

_start, _end, _stext, _etext, _srodata, _erodata, _sinittext,
_einittext

Use explicit casts to uintptr_t when it is not possible to use the
provided static inline functions.

M3CM: Rule-18.2: Subtraction between pointers shall only be applied to
pointers that address elements of the same array

Since we are changing the body of is_kernel_text and friends, take the
opportunity to remove the leading underscores in the local variables
names, which are violationg namespace rules. Also make the local p__
variable const.

https://wiki.sei.cmu.edu/confluence/display/c/ARR36-C.+Do+not+subtract+or+compare+two+pointers+that+do+not+refer+to+the+same+array

QAVerify: 2761
Signed-off-by: Stefano Stabellini <stefanos@xilinx.com>
CC: JBeulich@suse.com
CC: andrew.cooper3@citrix.com
---
Changes in v11:
- fix bug: a comma added by mistake
- use DECLARE_BOUNDS

Changes in v10:
- new patch

diff --git a/xen/arch/arm/alternative.c b/xen/arch/arm/alternative.c
index 52ed7edf6908a2b2439c64625df0f779971bed36..6013110a66bea2f5b821f136a8c63b437c68af26 100644 (file)
--- a/xen/arch/arm/alternative.c
+++ b/xen/arch/arm/alternative.c
@@ -188,7 +188,7 @@ static int __apply_alternatives_multi_stop(void *unused)
         int ret;
         struct alt_region region;
         mfn_t xen_mfn = virt_to_mfn(_start);
-        paddr_t xen_size = _end - _start;
+        paddr_t xen_size = xen_diff(_start, _end);
         unsigned int xen_order = get_order_from_bytes(xen_size);
         void *xenmap;
 
@@ -206,7 +206,7 @@ static int __apply_alternatives_multi_stop(void *unused)
         region.begin = __alt_instructions;
         region.end = __alt_instructions_end;
 
-        ret = __apply_alternatives(&region, xenmap - (void *)_start);
+        ret = __apply_alternatives(&region, xen_diff(_start, xenmap));
         /* The patching is not expected to fail during boot. */
         BUG_ON(ret != 0);
 

diff --git a/xen/arch/arm/arm32/livepatch.c b/xen/arch/arm/arm32/livepatch.c
index 41378a54aefcd6e0a11e6037320d609d82085356..83852d35cfbe2604a1df9cb763b5e6a5d77d0e61 100644 (file)
--- a/xen/arch/arm/arm32/livepatch.c
+++ b/xen/arch/arm/arm32/livepatch.c
@@ -56,7 +56,7 @@ void arch_livepatch_apply(struct livepatch_func *func)
     else
         insn = 0xe1a00000; /* mov r0, r0 */
 
-    new_ptr = func->old_addr - (void *)_start + vmap_of_xen_text;
+    new_ptr = xen_diff(_start, func->old_addr) + vmap_of_xen_text;
     len = len / sizeof(uint32_t);
 
     /* PATCH! */

diff --git a/xen/arch/arm/arm64/livepatch.c b/xen/arch/arm/arm64/livepatch.c
index 2247b925a05fcb9fd29b55e5a37d52a31177f964..c63a0ddd12e0dfc7a20ff1878cf8f34de834b191 100644 (file)
--- a/xen/arch/arm/arm64/livepatch.c
+++ b/xen/arch/arm/arm64/livepatch.c
@@ -43,7 +43,7 @@ void arch_livepatch_apply(struct livepatch_func *func)
     /* Verified in livepatch_verify_distance. */
     ASSERT(insn != AARCH64_BREAK_FAULT);
 
-    new_ptr = func->old_addr - (void *)_start + vmap_of_xen_text;
+    new_ptr = xen_diff(_start, func->old_addr) + vmap_of_xen_text;
     len = len / sizeof(uint32_t);
 
     /* PATCH! */

diff --git a/xen/arch/arm/livepatch.c b/xen/arch/arm/livepatch.c
index 279d52cc6cd78125f57a007d6a711a48419a25a3..1ba068c355684f0a8cdf20e0122b1adf25886776 100644 (file)
--- a/xen/arch/arm/livepatch.c
+++ b/xen/arch/arm/livepatch.c
@@ -27,7 +27,7 @@ int arch_livepatch_quiesce(void)
         return -EINVAL;
 
     text_mfn = virt_to_mfn(_start);
-    text_order = get_order_from_bytes(_end - _start);
+    text_order = get_order_from_bytes(xen_diff(_start, _end));
 
     /*
      * The text section is read-only. So re-map Xen to be able to patch
@@ -78,7 +78,7 @@ void arch_livepatch_revert(const struct livepatch_func *func)
     uint32_t *new_ptr;
     unsigned int len;
 
-    new_ptr = func->old_addr - (void *)_start + vmap_of_xen_text;
+    new_ptr = xen_diff(_start, func->old_addr) + vmap_of_xen_text;
 
     len = livepatch_insn_len(func);
     memcpy(new_ptr, func->opaque, len);

diff --git a/xen/arch/arm/mm.c b/xen/arch/arm/mm.c
index df52b26ab26333116d641398785b4e0772f1a5c5..ed168246d5d7936246a0b89ec863ecb803fb53a7 100644 (file)
--- a/xen/arch/arm/mm.c
+++ b/xen/arch/arm/mm.c
@@ -1074,7 +1074,7 @@ int modify_xen_mappings(unsigned long s, unsigned long e, unsigned int flags)
 }
 
 enum mg { mg_clear, mg_ro, mg_rw, mg_rx };
-static void set_pte_flags_on_range(const char *p, unsigned long l, enum mg mg)
+static void set_pte_flags_on_range(const void *p, unsigned long l, enum mg mg)
 {
     lpae_t pte;
     int i;
@@ -1085,8 +1085,8 @@ static void set_pte_flags_on_range(const char *p, unsigned long l, enum mg mg)
     ASSERT(!((unsigned long) p & ~PAGE_MASK));
     ASSERT(!(l & ~PAGE_MASK));
 
-    for ( i = (p - _start) / PAGE_SIZE; 
-          i < (p + l - _start) / PAGE_SIZE; 
+    for ( i = xen_diff(_start, p) / PAGE_SIZE;
+          i < (xen_diff(_start, p) + l) / PAGE_SIZE;
           i++ )
     {
         pte = xen_xenmap[i];

diff --git a/xen/arch/arm/setup.c b/xen/arch/arm/setup.c
index 444857a967a3082f051b18aafbcd6b4113190894..8d439434a3e38d060ce333b2f3aadf92268f1f3c 100644 (file)
--- a/xen/arch/arm/setup.c
+++ b/xen/arch/arm/setup.c
@@ -772,8 +772,9 @@ void __init start_xen(unsigned long boot_phys_offset,
 
     /* Register Xen's load address as a boot module. */
     xen_bootmodule = add_boot_module(BOOTMOD_XEN,
-                             (paddr_t)(uintptr_t)(_start + boot_phys_offset),
-                             (paddr_t)(uintptr_t)(_end - _start + 1), false);
+                             (paddr_t)(_start + boot_phys_offset),
+                             (paddr_t)(xen_diff(_start, _end) + 1),
+                             false);
     BUG_ON(!xen_bootmodule);
 
     setup_pagetables(boot_phys_offset);

diff --git a/xen/arch/x86/setup.c b/xen/arch/x86/setup.c
index 326432898e34a79e7d3488257696e104e76d6ebe..2ac7f625465532010797a974ae86ad1f73672655 100644 (file)
--- a/xen/arch/x86/setup.c
+++ b/xen/arch/x86/setup.c
@@ -1071,7 +1071,8 @@ void __init noreturn __start_xen(unsigned long mbi_p)
              * data until after we have switched to the relocated pagetables!
              */
             barrier();
-            move_memory(e + XEN_IMG_OFFSET, XEN_IMG_OFFSET, _end - _start, 1);
+            move_memory(e + XEN_IMG_OFFSET, XEN_IMG_OFFSET,
+                        xen_diff(_start, _end), 1);
 
             /* Walk initial pagetables, relocating page directory entries. */
             pl4e = __va(__pa(idle_pg_table));

diff --git a/xen/include/asm-arm/grant_table.h b/xen/include/asm-arm/grant_table.h
index 816e3c6d6834b391704ea0d46daf5553f9676884..1097791353b332d49e77651802d91ff20d116222 100644 (file)
--- a/xen/include/asm-arm/grant_table.h
+++ b/xen/include/asm-arm/grant_table.h
@@ -31,7 +31,8 @@ void gnttab_mark_dirty(struct domain *d, mfn_t mfn);
  * enough space for a large grant table
  */
 #define gnttab_dom0_frames()                                             \
-    min_t(unsigned int, opt_max_grant_frames, PFN_DOWN(_etext - _stext))
+    min_t(unsigned int, opt_max_grant_frames,                            \
+          PFN_DOWN(text_diff(_stext, _etext)))
 
 #define gnttab_init_arch(gt)                                             \
 ({                                                                       \

diff --git a/xen/include/xen/kernel.h b/xen/include/xen/kernel.h
index 548b64da9ffee906bfe7de78fcfe4d0abb35bdd0..c105a2ab86482b7c0986d7896de9d21f133e6131 100644 (file)
--- a/xen/include/xen/kernel.h
+++ b/xen/include/xen/kernel.h
@@ -5,6 +5,7 @@
  * 'kernel.h' contains some often-used function prototypes etc
  */
 
+#include <xen/lib.h>
 #include <xen/types.h>
 
 /*
@@ -65,28 +66,37 @@
        1;                                      \
 })
 
-extern char _start[], _end[], start[];
-#define is_kernel(p) ({                         \
-    char *__p = (char *)(unsigned long)(p);     \
-    (__p >= _start) && (__p < _end);            \
+extern char start[];
+typedef char xen_t;
+DECLARE_BOUNDS(xen, _start, _end);
+#define is_kernel(p) ({                                             \
+    const char *p__ = (const char *)(unsigned long)(p);             \
+    ((uintptr_t)p__ >= (uintptr_t)_start &&                         \
+    xen_lt(p__, _end));                                             \
 })
 
-extern char _stext[], _etext[];
-#define is_kernel_text(p) ({                    \
-    char *__p = (char *)(unsigned long)(p);     \
-    (__p >= _stext) && (__p < _etext);          \
+typedef char text_t;
+DECLARE_BOUNDS(text, _stext, _etext);
+#define is_kernel_text(p) ({                                        \
+    const char *p__ = (const char *)(unsigned long)(p);             \
+    ((uintptr_t)p__ >= (uintptr_t) _stext &&                        \
+    text_lt(p__, _etext));                                          \
 })
 
-extern const char _srodata[], _erodata[];
-#define is_kernel_rodata(p) ({                  \
-    const char *__p = (const char *)(unsigned long)(p);     \
-    (__p >= _srodata) && (__p < _erodata);      \
+typedef char rodata_t;
+DECLARE_BOUNDS(rodata, _srodata, _erodata);
+#define is_kernel_rodata(p) ({                                      \
+    const char *p__ = (const char *)(unsigned long)(p);             \
+    ((uintptr_t)p__ >= (uintptr_t)_srodata &&                       \
+    rodata_lt(p__, _erodata));                                      \
 })
 
-extern char _sinittext[], _einittext[];
-#define is_kernel_inittext(p) ({                \
-    char *__p = (char *)(unsigned long)(p);     \
-    (__p >= _sinittext) && (__p < _einittext);  \
+typedef char inittext_t;
+DECLARE_BOUNDS(inittext, _sinittext, _einittext);
+#define is_kernel_inittext(p) ({                                    \
+    const char *p__ = (const char *)(unsigned long)(p);             \
+    ((uintptr_t)p__ >= (uintptr_t) _sinittext &&                    \
+    inittext_lt(p__, _einittext));                                  \
 })
 
 extern enum system_state {