lib/libutee/tcb.c

1 // SPDX-License-Identifier: BSD-2-Clause
6  * Support for Thread-Local Storage (TLS) ABIs for ARMv7/Aarch32 and Aarch64.
8  * TAs are currently single-threaded, so the only benefit of implementing these
10  * single-threaded. Such as, the g++ compiler from the GCC toolchain targeting a
11  * "Posix thread" Linux runtime, which OP-TEE has been using for quite some time
12  * (arm-linux-gnueabihf-* and aarch64-linux-gnu-*). This allows building C++ TAs
13  * without having to build a specific toolchain with --disable-threads.
17  *  - "TLS data structures variant 1" (section 3): the AArch64 compiler uses the
21  *  - The "General Dynamic access model" (section 4.1): the ARMv7/Aarch32
31  * [1] "ELF Handling For Thread-Local Storage"
43 /* DTV - Dynamic Thread Vector
50  * tls[2 .. (size-1)] are for shared libraries
67 	 * plus some zero-initialized space for .tbss.
74  * change if multi-threading is introduced.
98 		for (j = 0; j < dlpi->dlpi_phnum; j++) {  in __utee_tcb_init()
99 			phdr = dlpi->dlpi_phdr + j;  in __utee_tcb_init()
100 			if (phdr->p_type == PT_TLS) {  in __utee_tcb_init()
101 				total_size += phdr->p_memsz;  in __utee_tcb_init()
113 	/* (Re-)allocate the TCB */  in __utee_tcb_init()
120 	/* (Re-)allocate the DTV. + 1 since dtv[0] holds the size */  in __utee_tcb_init()
122 	_tcb->dtv = malloc_flags(MAF_ZERO_INIT, _tcb->dtv, 1, size);  in __utee_tcb_init()
123 	if (!_tcb->dtv) {  in __utee_tcb_init()
132 		for (j = 0; j < dlpi->dlpi_phnum; j++) {  in __utee_tcb_init()
133 			phdr = dlpi->dlpi_phdr + j;  in __utee_tcb_init()
134 			if (phdr->p_type != PT_TLS)  in __utee_tcb_init()
136 			if (size + phdr->p_memsz <= _tls_size) {  in __utee_tcb_init()
140 			_tcb->dtv[i + 1].tls = _tcb->tls + size;  in __utee_tcb_init()
142 			memcpy(_tcb->tls + size,  in __utee_tcb_init()
143 			       (void *)(dlpi->dlpi_addr + phdr->p_vaddr),  in __utee_tcb_init()
144 			       phdr->p_filesz);  in __utee_tcb_init()
146 			memset(_tcb->tls + size + phdr->p_filesz, 0,  in __utee_tcb_init()
147 			       phdr->p_memsz - phdr->p_filesz);  in __utee_tcb_init()
148 			size += phdr->p_memsz;  in __utee_tcb_init()
151 	_tcb->dtv[0].size = i;  in __utee_tcb_init()
172 	return _tcb->dtv[ti->module].tls + ti->offset;  in __tls_get_addr()
184 	 * dlpi_tls_data is thread-specific so if we were to support  in dl_iterate_phdr()
185 	 * multi-threading, we would need one copy of struct dl_phdr_info per  in dl_iterate_phdr()
186 	 * thread. Could be a pre-allocated area, or could be allocated on the  in dl_iterate_phdr()
198 		dlpi->dlpi_tls_data = NULL;  in dl_iterate_phdr()
199 		id = dlpi->dlpi_tls_modid;  in dl_iterate_phdr()
201 			dlpi->dlpi_tls_data = _tcb->dtv[id].tls;  in dl_iterate_phdr()