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head/libexec/rtld-elf/aarch64/rtld_start.S

Show First 20 Lines • Show All 112 Lines • ▼ Show 20 LinesENTRY(_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)