JIT is violating Darwin W^X if not targeting macOS #212
Comments
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As far as I heard no jit works on ios, it is better to disable it. |
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After several patching I could avoid that SIGBUS using METHOD1, but then resulting all pcre2_jit_tests failed --- a/src/sljit/sljitExecAllocator.c 1645780892.000000000
+++ b/src/sljit/sljitExecAllocator.c 1677493457.634072731
@@ -158,7 +158,62 @@ static SLJIT_INLINE void apple_update_wx
}
#endif /* SLJIT_CONFIG_X86 */
#else /* !TARGET_OS_OSX */
+#define _COMM_PAGE_START_ADDRESS (0x0000000FFFFFC000ULL) /* In TTBR0 */
+#define _COMM_PAGE_APRR_SUPPORT (_COMM_PAGE_START_ADDRESS + 0x10C)
+#define _COMM_PAGE_APPR_WRITE_ENABLE (_COMM_PAGE_START_ADDRESS + 0x110)
+#define _COMM_PAGE_APRR_WRITE_DISABLE (_COMM_PAGE_START_ADDRESS + 0x118)
+
#define SLJIT_MAP_JIT (MAP_JIT)
+#ifdef METHOD1
+#define SLJIT_UPDATE_WX_FLAGS(from, to, enable_exec) \
+ apple_update_wx_flags(enable_exec)
+#warning Using https://siguza.github.io/APRR/
+static SLJIT_INLINE void apple_update_wx_flags(sljit_s32 enable_exec)
+{
+ uint8_t aprr_support = *(volatile uint8_t *)_COMM_PAGE_APRR_SUPPORT;
+ if (aprr_support == 0 || aprr_support > 3) {
+ return;
+ } else if (aprr_support == 1) {
+ __asm__ __volatile__ (
+ "mov x0, %0\n"
+ "ldr x0, [x0]\n"
+ "msr S3_4_c15_c2_7, x0\n"
+ "isb sy\n"
+ :: "r" (enable_exec ? _COMM_PAGE_APRR_WRITE_DISABLE
+ : _COMM_PAGE_APPR_WRITE_ENABLE)
+ : "memory", "x0"
+ );
+ } else {
+ __asm__ __volatile__ (
+ "mov x0, %0\n"
+ "ldr x0, [x0]\n"
+ "msr S3_6_c15_c1_5, x0\n"
+ "isb sy\n"
+ :: "r" (enable_exec ? _COMM_PAGE_APRR_WRITE_DISABLE
+ : _COMM_PAGE_APPR_WRITE_ENABLE)
+ : "memory", "x0"
+ );
+ }
+}
+#elif defined(METHOD2)
+#warning Using mprotect
+#define SLJIT_UPDATE_WX_FLAGS(from, to, enable_exec) \
+ update_wx_flags(from, to, enable_exec)
+static SLJIT_INLINE void update_wx_flags(void *from, void *to, int enable_exec)
+{
+ sljit_uw page_mask = (sljit_uw)get_page_alignment();
+ sljit_uw start = (sljit_uw)from;
+ sljit_uw end = (sljit_uw)to;
+ int prot = PROT_READ | (enable_exec ? PROT_EXEC : PROT_WRITE);
+
+ SLJIT_ASSERT(start < end);
+
+ start &= ~page_mask;
+ end = (end + page_mask) & ~page_mask;
+
+ mprotect((void*)start, end - start, prot);
+}
+#endif
#endif /* TARGET_OS_OSX */
#endif /* __APPLE__ && MAP_JIT */
#ifndef SLJIT_UPDATE_WX_FLAGS |
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The last thing I heard, no jit is allowed in iOS, because it hurts monetizing the platform. I also heard jit works on jailbroken devices, but that is special case. |
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basically, there have JIT support on iOS with |
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Sounds interesting. Unfortunately I cannot help since I have no access to any Apple device, but somebody else might know something. Maybe in some apple dev forums. |
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Retried today and have to say defining so the thing is:
JIT ( |
On iOS there's no
pthread_jit*API provided by Apple, resultingPROT_WRITEandPROT_EXEChas been set at same time, causingKERN_PROTECTION_FAILUREThe text was updated successfully, but these errors were encountered: