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c61b4d41c9
The pointer guard used for pointer mangling was not initialized for static applications resulting in the security feature being disabled. The pointer guard is now correctly initialized to a random value for static applications. Existing static applications need to be recompiled to take advantage of the fix. The test tst-ptrguard1-static and tst-ptrguard1 add regression coverage to ensure the pointer guards are sufficiently random and initialized to a default value.
19 lines
511 B
C
19 lines
511 B
C
#include <stdint.h>
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#define STACK_CHK_GUARD \
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({ uintptr_t x; asm ("ear %0,%%a0; sllg %0,%0,32; ear %0,%%a1; lg %0,0x28(%0)" : "=a" (x)); x; })
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/* On s390/s390x there is no unique pointer guard, instead we use the
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same value as the stack guard. */
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#define POINTER_CHK_GUARD \
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({ \
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uintptr_t x; \
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asm ("ear %0,%%a0;" \
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"sllg %0,%0,32;" \
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"ear %0,%%a1;" \
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"lg %0,%1(%0)" \
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: "=a" (x) \
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: "i" (offsetof (tcbhead_t, stack_guard))); \
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x; \
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})
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