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x86: Support x32 and IBT in heap trampoline

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Add x32 and IBT support to x86 heap trampoline implementation with a
testcase.

2024-02-13  Jakub Jelinek  <jakub@redhat.com>
	    H.J. Lu  <hjl.tools@gmail.com>

libgcc/

	PR target/113855
	* config/i386/heap-trampoline.c (trampoline_insns): Add IBT
	support and pad to the multiple of 4 bytes.  Use movabsq
	instead of movabs in comments.  Add -mx32 variant.

gcc/testsuite/

	PR target/113855
	* gcc.dg/heap-trampoline-1.c: New test.
	* lib/target-supports.exp (check_effective_target_heap_trampoline):
	New.
This commit is contained in:
H.J. Lu 2024-02-13 08:40:52 -08:00 • committed by H.J. Lu
parent 2c2f57e415
commit 67ce5c9716
3 changed files with 74 additions and 3 deletions
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23
gcc/testsuite/gcc.dg/heap-trampoline-1.c Normal file
View file

@ -0,0 +1,23 @@
/* { dg-do run { target heap_trampoline } } */
/* { dg-options "-ftrampoline-impl=heap" } */
__attribute__((noipa)) int
bar (int (*fn) (int))
{
return fn (42) + 1;
}
int
main ()
{
int a = 0;
int foo (int x) { if (x != 42) __builtin_abort (); return ++a; }
if (bar (foo) != 2 || a != 1)
__builtin_abort ();
if (bar (foo) != 3 || a != 2)
__builtin_abort ();
a = 42;
if (bar (foo) != 44 || a != 43)
__builtin_abort ();
return 0;
}

12
gcc/testsuite/lib/target-supports.exp
View file

@ -13477,3 +13477,15 @@ proc dg-require-python-h { args } {
eval lappend extra-tool-flags $python_flags
verbose "After appending, extra-tool-flags: ${extra-tool-flags}" 3
}
# Return 1 if the target supports heap-trampoline, 0 otherwise.
proc check_effective_target_heap_trampoline {} {
if { [istarget aarch64*-*-linux*]
|| [istarget i?86-*-darwin*]
|| [istarget x86_64-*-darwin*]
|| [istarget i?86-*-linux*]
|| [istarget x86_64-*-linux*] } {
return 1
}
return 0
}

42
libgcc/config/i386/heap-trampoline.c
View file

@ -30,28 +30,64 @@ void __gcc_nested_func_ptr_created (void *chain, void *func, void *dst);
void __gcc_nested_func_ptr_deleted (void);
#if __x86_64__
#ifdef __LP64__
static const uint8_t trampoline_insns[] = {
/* movabs $<func>,%r11 */
#if defined __CET__ && (__CET__ & 1) != 0
/* endbr64. */
0xf3, 0x0f, 0x1e, 0xfa,
#endif
/* movabsq $<func>,%r11 */
0x49, 0xbb,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
/* movabs $<chain>,%r10 */
/* movabsq $<chain>,%r10 */
0x49, 0xba,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
/* rex.WB jmpq *%r11 */
0x41, 0xff, 0xe3
0x41, 0xff, 0xe3,
/* Pad to the multiple of 4 bytes. */
0x90
};
#else
static const uint8_t trampoline_insns[] = {
#if defined __CET__ && (__CET__ & 1) != 0
/* endbr64. */
0xf3, 0x0f, 0x1e, 0xfa,
#endif
/* movl $<func>,%r11d */
0x41, 0xbb,
0x00, 0x00, 0x00, 0x00,
/* movl $<chain>,%r10d */
0x41, 0xba,
0x00, 0x00, 0x00, 0x00,
/* rex.WB jmpq *%r11 */
0x41, 0xff, 0xe3,
/* Pad to the multiple of 4 bytes. */
0x90
};
#endif
union ix86_trampoline {
uint8_t insns[sizeof(trampoline_insns)];
struct __attribute__((packed)) fields {
#if defined __CET__ && (__CET__ & 1) != 0
uint8_t endbr64[4];
#endif
uint8_t insn_0[2];
void *func_ptr;
uint8_t insn_1[2];
void *chain_ptr;
uint8_t insn_2[3];
uint8_t pad;
} fields;
};