Differential D18417 Diff 51754 libexec/rtld-elf/aarch64/rtld_start.S

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libexec/rtld-elf/aarch64/rtld_start.S

Show First 20 Lines • Show All 112 Lines • ▼ Show 20 Lines	ENTRY(_rtld_bind_start)
ldp xzr, x30, [sp], #16		ldp xzr, x30, [sp], #16

/* Call into the correct function */		/* Call into the correct function */
br x16		br x16
.cfi_endproc		.cfi_endproc
END(_rtld_bind_start)		END(_rtld_bind_start)

/*		/*
* uint64_t _rtld_tlsdesc(struct tlsdesc *);		* struct rel_tlsdesc {
		* uint64_t resolver_fnc;
		* uint64_t resolver_arg;
*		*
* struct tlsdesc {
* uint64_t ptr;
* uint64_t data;
* };
*		*
* Returns the data.		* uint64_t _rtld_tlsdesc_static(struct rel_tlsdesc *);
		*
		* Resolver function for TLS symbols resolved at load time
*/		*/
ENTRY(_rtld_tlsdesc)		ENTRY(_rtld_tlsdesc_static)
		.cfi_startproc
ldr x0, [x0, #8]		ldr x0, [x0, #8]
ret		ret
END(_rtld_tlsdesc)		.cfi_endproc
		END(_rtld_tlsdesc_static)

/*		/*
* uint64_t _rtld_tlsdesc_dynamic(struct tlsdesc *);		* uint64_t _rtld_tlsdesc_undef(void);
*		*
* TODO: We could lookup the saved index here to skip saving the entire stack.		* Resolver function for weak and undefined TLS symbols
*/		*/
		ENTRY(_rtld_tlsdesc_undef)
		.cfi_startproc
		str x1, [sp, #-16]!
		.cfi_adjust_cfa_offset 16

		mrs x1, tpidr_el0
		ldr x0, [x0, #8]
		sub x0, x0, x1

		ldr x1, [sp], #16
		.cfi_adjust_cfa_offset -16
		.cfi_endproc
		ret
		END(_rtld_tlsdesc_undef)

		/*
		* uint64_t _rtld_tlsdesc_dynamic(struct rel_tlsdesc *);
		*
		* Resolver function for TLS symbols from dlopen()
		*/
ENTRY(_rtld_tlsdesc_dynamic)		ENTRY(_rtld_tlsdesc_dynamic)
/* Store any registers we may use in rtld_tlsdesc_handle */		.cfi_startproc
stp x29, x30, [sp, #-(10 * 16)]!
		/* Save registers used in fast path */
		stp x1, x2, [sp, #(-2 * 16)]!
		stp x3, x4, [sp, #(1 * 16)]
		.cfi_adjust_cfa_offset 2 * 16
		.cfi_rel_offset x1, 0
		.cfi_rel_offset x2, 8
		.cfi_rel_offset x3, 16
		.cfi_rel_offset x4, 24

		/* Test fastpath - inlined version of tls_get_addr_common(). */
		ldr x1, [x0, #8] /* tlsdesc ptr */
		mrs x4, tpidr_el0
		ldr x0, [x4] /* DTV pointer */
		ldr x2, [x0] /* dtv[0] (generation count) */
		ldr x3, [x1] /* tlsdec->dtv_gen */
		cmp x2, x3
		b.ne 1f /* dtv[0] != tlsdec->dtv_gen */

		ldr w2, [x1, #8] /* tlsdec->tls_index */
		add w2, w2, #1
		ldr x3, [x0, w2, sxtw #3] /* dtv[tlsdesc->tls_index + 1] */
		cbz x3, 1f

		/* Return (dtv[tlsdesc->tls_index + 1] + tlsdesc->tls_offs - tp) */
		ldr x2, [x1, #16] /* tlsdec->tls_offs */
		add x2, x2, x3
		sub x0, x2, x4
		/* Restore registers and return */
		ldp x3, x4, [sp, #(1 * 16)]
		ldp x1, x2, [sp], #(2 * 16)
		.cfi_adjust_cfa_offset -2 * 16
		ret

		/*
		* Slow path
		* return(
		* tls_get_addr_common(tp, tlsdesc->tls_index, tlsdesc->tls_offs));
		*
		*/
		1:
		/* Save all interger registers */
		stp x29, x30, [sp, #-(8 * 16)]!
		.cfi_adjust_cfa_offset 8 * 16
		.cfi_rel_offset x29, 0
		.cfi_rel_offset x30, 8

mov x29, sp		mov x29, sp
stp x1, x2, [sp, #(1 * 16)]		stp x5, x6, [sp, #(1 * 16)]
stp x3, x4, [sp, #(2 * 16)]		stp x7, x8, [sp, #(2 * 16)]
stp x5, x6, [sp, #(3 * 16)]		stp x9, x10, [sp, #(3 * 16)]
stp x7, x8, [sp, #(4 * 16)]		stp x11, x12, [sp, #(4 * 16)]
stp x9, x10, [sp, #(5 * 16)]		stp x13, x14, [sp, #(5 * 16)]
stp x11, x12, [sp, #(6 * 16)]		stp x15, x16, [sp, #(6 * 16)]
stp x13, x14, [sp, #(7 * 16)]		stp x17, x18, [sp, #(7 * 16)]
stp x15, x16, [sp, #(8 * 16)]		.cfi_rel_offset x5, 16
stp x17, x18, [sp, #(9 * 16)]		.cfi_rel_offset x6, 24
		.cfi_rel_offset x7, 32
		.cfi_rel_offset x8, 40
		.cfi_rel_offset x9, 48
		.cfi_rel_offset x10, 56
		.cfi_rel_offset x11, 64
		.cfi_rel_offset x12, 72
		.cfi_rel_offset x13, 80
		.cfi_rel_offset x14, 88
		.cfi_rel_offset x15, 96
		.cfi_rel_offset x16, 104
		.cfi_rel_offset x17, 112
		.cfi_rel_offset x18, 120

/* Find the tls offset */		/* Find the tls offset */
ldr x0, [x0, #8]		mov x0, x4 /* tp */
mov x1, #1		mov x3, x1 /* tlsdesc ptr */
bl rtld_tlsdesc_handle		ldr w1, [x3, #8] /* tlsdec->tls_index */
		ldr x2, [x3, #16] /* tlsdec->tls_offs */
		bl tls_get_addr_common
		mrs x1, tpidr_el0
		sub x0, x0, x1

/* Restore the registers */		/* Restore slow patch registers */
ldp x17, x18, [sp, #(9 * 16)]		ldp x17, x18, [sp, #(7 * 16)]
ldp x15, x16, [sp, #(8 * 16)]		ldp x15, x16, [sp, #(6 * 16)]
ldp x13, x14, [sp, #(7 * 16)]		ldp x13, x14, [sp, #(5 * 16)]
ldp x11, x12, [sp, #(6 * 16)]		ldp x11, x12, [sp, #(4 * 16)]
ldp x9, x10, [sp, #(5 * 16)]		ldp x9, x10, [sp, #(3 * 16)]
ldp x7, x8, [sp, #(4 * 16)]		ldp x7, x8, [sp, #(2 * 16)]
ldp x5, x6, [sp, #(3 * 16)]		ldp x5, x6, [sp, #(1 * 16)]
ldp x3, x4, [sp, #(2 * 16)]		ldp x29, x30, [sp], #(8 * 16)
ldp x1, x2, [sp, #(1 * 16)]		.cfi_adjust_cfa_offset -8 * 16
ldp x29, x30, [sp], #(10 * 16)		.cfi_restore x29
		.cfi_restore x30

		/* Restore fast path registers and return */
		ldp x3, x4, [sp, #16]
		ldp x1, x2, [sp], #(2 * 16)
		.cfi_adjust_cfa_offset -2 * 16
		.cfi_endproc
ret		ret
END(_rtld_tlsdesc_dynamic)		END(_rtld_tlsdesc_dynamic)