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| 3 | |
| 4 | * simple_ring_buffer is used by the pKVM hypervisor which does not have access
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| 5 | * to all kernel symbols. Whatever is undefined when compiling this file is
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| 6 | * compiler and tooling-generated symbols that can safely be ignored for
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| 7 | * simple_ring_buffer.
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| 8 |
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| 9 |
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| 10 | #include <linux/atomic.h>
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| 11 | #include <linux/string.h>
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| 12 | #include <asm/local.h>
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| 13 | #include <asm/page.h>
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| 14 |
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| 15 | void undefsyms_base(void *p, int n);
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| 16 |
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| 17 | static char page[PAGE_SIZE] __aligned(PAGE_SIZE);
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| 18 |
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| 19 | void undefsyms_base(void *p, int n)
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| 20 | {
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| 21 | char buffer[256] = { 0 };
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| 22 | u32 u = 0;
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| 23 |
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| 24 | memset((char * volatile)page, 8, PAGE_SIZE);
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| 25 | memset((char * volatile)buffer, 8, sizeof(buffer));
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| 26 | memcpy((void * volatile)p, buffer, sizeof(buffer));
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| 27 | cmpxchg((u32 * volatile)&u, 0, 8);
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| 28 | cmpxchg((unsigned long *)p, 0, 8);
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| 29 | local_set((local_t *)p, 8);
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| 30 | WARN_ON(n == 0xdeadbeef);
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| 31 | }
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