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	When dynamically linking, ifunc resolvers are called before TLS is
initialized, so they cannot be safely stack-protected.
We avoid disabling stack-protection on large numbers of files by
using __attribute__ ((__optimize__ ("-fno-stack-protector")))
to turn it off just for the resolvers themselves.  (We provide
the attribute even when statically linking, because we will later
use it elsewhere too.)
		
	
		
			
				
	
	
		
			101 lines
		
	
	
		
			1.6 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			101 lines
		
	
	
		
			1.6 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /* Test STT_GNU_IFUNC symbols:
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| 
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|    1. Direct function call.
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|    2. Function pointer.
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|    3. Visibility.
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|  */
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| #include "ifunc-sel.h"
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| 
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| int global = -1;
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| /* Can't use __attribute__((visibility("protected"))) until the GCC bug:
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| 
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|    https://gcc.gnu.org/bugzilla/show_bug.cgi?id=65248
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| 
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|    is fixed.  */
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| asm (".protected global");
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| 
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| static int
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| one (void)
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| {
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|   return 1;
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| }
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| 
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| static int
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| minus_one (void)
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| {
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|   return -1;
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| }
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| 
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| static int
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| zero (void)
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| {
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|   return 0;
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| }
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| 
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| void * foo_ifunc (void) __asm__ ("foo");
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| __asm__(".type foo, %gnu_indirect_function");
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| 
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| void *
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| inhibit_stack_protector
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| foo_ifunc (void)
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| {
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|   return ifunc_sel (one, minus_one, zero);
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| }
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| 
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| void * foo_hidden_ifunc (void) __asm__ ("foo_hidden");
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| __asm__(".type foo_hidden, %gnu_indirect_function");
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| 
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| void *
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| inhibit_stack_protector
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| foo_hidden_ifunc (void)
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| {
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|   return ifunc_sel (minus_one, one, zero);
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| }
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| 
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| void * foo_protected_ifunc (void) __asm__ ("foo_protected");
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| __asm__(".type foo_protected, %gnu_indirect_function");
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| 
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| void *
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| inhibit_stack_protector
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| foo_protected_ifunc (void)
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| {
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|   return ifunc_sel (one, zero, minus_one);
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| }
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| 
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| /* Test hidden indirect function.  */
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| __asm__(".hidden foo_hidden");
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| 
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| /* Test protected indirect function.  */
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| __asm__(".protected foo_protected");
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| 
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| extern int foo (void);
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| extern int foo_hidden (void);
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| extern int foo_protected (void);
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| extern int ret_foo;
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| extern int ret_foo_hidden;
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| extern int ret_foo_protected;
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| 
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| #define FOO_P
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| typedef int (*foo_p) (void);
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| 
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| foo_p
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| get_foo_p (void)
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| {
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|   ret_foo = foo ();
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|   return foo;
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| }
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| 
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| foo_p
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| get_foo_hidden_p (void)
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| {
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|   ret_foo_hidden = foo_hidden ();
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|   return foo_hidden;
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| }
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| 
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| foo_p
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| get_foo_protected_p (void)
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| {
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|   ret_foo_protected = foo_protected ();
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|   return foo_protected;
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| }
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