This produces a PIE binary with a variety of p_align requirements, suitable for verifying that the load address meets that alignment requirement. Signed-off-by: Chris Kennelly <ckennelly@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Cc: Shuah Khan <shuah@kernel.org> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: David Rientjes <rientjes@google.com> Cc: Fangrui Song <maskray@google.com> Cc: Hugh Dickens <hughd@google.com> Cc: Ian Rogers <irogers@google.com> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Nick Desaulniers <ndesaulniers@google.com> Cc: Sandeep Patil <sspatil@google.com> Cc: Song Liu <songliubraving@fb.com> Cc: Suren Baghdasaryan <surenb@google.com> Link: https://lkml.kernel.org/r/20200820170541.1132271-3-ckennelly@google.com Link: https://lkml.kernel.org/r/20200821233848.3904680-3-ckennelly@google.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
		
			
				
	
	
		
			69 lines
		
	
	
		
			1.5 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			69 lines
		
	
	
		
			1.5 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| // SPDX-License-Identifier: GPL-2.0-only
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| #ifndef _GNU_SOURCE
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| #define _GNU_SOURCE
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| #endif
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| #include <link.h>
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| #include <stdio.h>
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| #include <stdlib.h>
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| 
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| struct Statistics {
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| 	unsigned long long load_address;
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| 	unsigned long long alignment;
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| };
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| 
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| int ExtractStatistics(struct dl_phdr_info *info, size_t size, void *data)
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| {
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| 	struct Statistics *stats = (struct Statistics *) data;
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| 	int i;
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| 
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| 	if (info->dlpi_name != NULL && info->dlpi_name[0] != '\0') {
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| 		// Ignore headers from other than the executable.
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| 		return 2;
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| 	}
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| 
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| 	stats->load_address = (unsigned long long) info->dlpi_addr;
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| 	stats->alignment = 0;
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| 
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| 	for (i = 0; i < info->dlpi_phnum; i++) {
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| 		if (info->dlpi_phdr[i].p_type != PT_LOAD)
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| 			continue;
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| 
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| 		if (info->dlpi_phdr[i].p_align > stats->alignment)
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| 			stats->alignment = info->dlpi_phdr[i].p_align;
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| 	}
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| 
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| 	return 1;  // Terminate dl_iterate_phdr.
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| }
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| 
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| int main(int argc, char **argv)
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| {
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| 	struct Statistics extracted;
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| 	unsigned long long misalign;
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| 	int ret;
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| 
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| 	ret = dl_iterate_phdr(ExtractStatistics, &extracted);
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| 	if (ret != 1) {
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| 		fprintf(stderr, "FAILED\n");
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| 		return 1;
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| 	}
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| 
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| 	if (extracted.alignment == 0) {
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| 		fprintf(stderr, "No alignment found\n");
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| 		return 1;
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| 	} else if (extracted.alignment & (extracted.alignment - 1)) {
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| 		fprintf(stderr, "Alignment is not a power of 2\n");
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| 		return 1;
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| 	}
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| 
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| 	misalign = extracted.load_address & (extracted.alignment - 1);
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| 	if (misalign) {
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| 		printf("alignment = %llu, load_address = %llu\n",
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| 			extracted.alignment, extracted.load_address);
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| 		fprintf(stderr, "FAILED\n");
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| 		return 1;
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| 	}
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| 
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| 	fprintf(stderr, "PASS\n");
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| 	return 0;
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| }
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