stdatomic.h incompatible with PSRAM (IDFGH-2549)

[szmodz]

GCC atomic builtins are not compatible with PSRAM addresses, as they rely on s32c1i.

This in turn makes the compiler incompatible with the C standard (stdatomic.h), and will cause difficult to find problems with valid, standard C code.

Worst part is, using stdatomic.h with PSRAM will not cause any exceptions. It will simply result in difficult to find race conditions.

esp-idf is also affected by this issue. Examples include the ethernet and SPI drivers.

esp-idf/components/esp_eth/src/esp_eth.c

Line 364 in 647cb62

esp_err_t esp_eth_increase_reference(esp_eth_handle_t hdl)

esp-idf/components/esp_eth/src/esp_eth.c

Line 174 in 647cb62

esp_eth_driver_t *eth_driver = calloc(1, sizeof(esp_eth_driver_t));

(no MALLOC_CAP_INTERNAL)

esp-idf/components/driver/spi_master.c

Line 242 in 647cb62

spihost[host]=malloc(sizeof(spi_host_t));

(also no MALLOC_CAP_INTERNAL)

esp-idf/components/driver/spi_master.c

Line 559 in 647cb62

atomic_compare_exchange_weak(&host->acquire_cs, &no_cs, handle->id);

[szmodz]

#include <stdatomic.h>

void xfaa(atomic_int *x) {
    atomic_fetch_add(x, 1);
}

xtensa-esp32-elf-gcc -O2 -std=gnu11 -S test.c

	.file	"test.c"
	.text
	.align	4
	.global	xfaa
	.type	xfaa, @function
xfaa:
	entry	sp, 32
	memw
	l32i.n	a8, a2, 0
.L2:
	mov.n	a9, a8
	addi.n	a10, a8, 1
	wsr	a8, SCOMPARE1
	s32c1i	a10, a2, 0        <----------------
	mov.n	a8, a10
	bne	a10, a9, .L2
	retw.n
	.size	xfaa, .-xfaa
	.ident	"GCC: (crosstool-NG esp-2019r2) 8.2.0"

comment regarding s32c1i in esp-idf source (as no other documentation is available):

esp-idf/components/freertos/port.c

Line 439 in 647cb62

/*

[suda-morris]

Thanks @szmodz Well spotted!

[szmodz]

Build errors are unrelated. This is entirely run-time.

…

On Wed, 22 Jan 2020, 21:38 HudsonProdigy, ***@***.***> wrote: having issues building 3.3.1 and 4.0-rc getting all kinds of stdatomic.h errors. Im guessing it is related to this issue. In file included from /Users/user/esp/esp-idf-v4.0-rc/components/esp_eth/src/esp_eth.c:15:0: /Users/user/esp/esp-idf-v4.0-rc/components/newlib/include/stdatomic.h: In function 'atomic_flag_test_and_set_explicit': /Users/user/esp/esp-idf-v4.0-rc/components/newlib/include/stdatomic.h:271:31: error: request for member '__val' in something not a structure or union __atomic_exchange_n(&(object)->__val, desired, order) ^ /Users/user/esp/esp-idf-v4.0-rc/components/newlib/include/stdatomic.h:387:10: note: in expansion of macro 'atomic_exchange_explicit' return (atomic_exchange_explicit(&__object->__flag, 1, __order)); ^ /Users/user/esp/esp-idf-v4.0-rc/components/newlib/include/stdatomic.h:387:2: error: incompatible type for argument 1 of '__atomic_exchange_n' return (atomic_exchange_explicit(&__object->__flag, 1, __order)); ^ /Users/user/esp/esp-idf-v4.0-rc/components/newlib/include/stdatomic.h: In function 'atomic_flag_clear_explicit': /Users/user/esp/esp-idf-v4.0-rc/components/newlib/include/stdatomic.h:285:28: error: request for member '__val' in something not a structure or union __atomic_store_n(&(object)->__val, desired, order) ^ /Users/user/esp/esp-idf-v4.0-rc/components/newlib/include/stdatomic.h:394:2: note: in expansion of macro 'atomic_store_explicit' atomic_store_explicit(&__object->__flag, 0, __order); ^ /Users/user/esp/esp-idf-v4.0-rc/components/newlib/include/stdatomic.h:394:2: error: incompatible type for argument 1 of '__atomic_store_n' /Users/user/esp/esp-idf-v4.0-rc/components/esp_eth/src/esp_eth.c: In function 'esp_eth_driver_install': /Users/user/esp/esp-idf-v4.0-rc/components/newlib/include/stdatomic.h:91:47: error: request for member '__val' in something not a structure or union #define atomic_init(obj, value) ((void)((obj)->__val = (value))) ^ /Users/user/esp/esp-idf-v4.0-rc/components/esp_eth/src/esp_eth.c:174:5: note: in expansion of macro 'atomic_init' atomic_init(&eth_driver->ref_count, 1); ^ /Users/user/esp/esp-idf-v4.0-rc/components/esp_eth/src/esp_eth.c: In function 'esp_eth_driver_uninstall': /Users/user/esp/esp-idf-v4.0-rc/components/newlib/include/stdatomic.h:283:27: error: request for member '__val' in something not a structure or union __atomic_load_n(&(object)->__val, order) ^ /Users/user/esp/esp-idf-v4.0-rc/components/esp_eth/src/esp_eth.c:27:15: note: in definition of macro 'ETH_CHECK' if (!(a)) \ ^ /Users/user/esp/esp-idf-v4.0-rc/components/newlib/include/stdatomic.h:365:2: note: in expansion of macro 'atomic_load_explicit' atomic_load_explicit(object, memory_order_seq_cst) ^ /Users/user/esp/esp-idf-v4.0-rc/components/esp_eth/src/esp_eth.c:215:15: note: in expansion of macro 'atomic_load' ETH_CHECK(atomic_load(&eth_driver->ref_count) == 1, ^ /Users/user/esp/esp-idf-v4.0-rc/components/esp_eth/src/esp_eth.c:215:5: error: incompatible type for argument 1 of '__atomic_load_n' ETH_CHECK(atomic_load(&eth_driver->ref_count) == 1, ^ In file included from /Users/user/esp/esp-idf-v4.0-rc/components/esp_eth/src/esp_eth.c:15:0: /Users/user/esp/esp-idf-v4.0-rc/components/esp_eth/src/esp_eth.c: In function 'esp_eth_increase_reference': /Users/user/esp/esp-idf-v4.0-rc/components/newlib/include/stdatomic.h:273:30: error: request for member '__val' in something not a structure or union __atomic_fetch_add(&(object)->__val, operand, order) ^ /Users/user/esp/esp-idf-v4.0-rc/components/newlib/include/stdatomic.h:355:2: note: in expansion of macro 'atomic_fetch_add_explicit' atomic_fetch_add_explicit(object, operand, memory_order_seq_cst) ^ /Users/user/esp/esp-idf-v4.0-rc/components/esp_eth/src/esp_eth.c:341:5: note: in expansion of macro 'atomic_fetch_add' atomic_fetch_add(&eth_driver->ref_count, 1); ^ /Users/user/esp/esp-idf-v4.0-rc/components/esp_eth/src/esp_eth.c:341:5: error: incompatible type for argument 1 of '__atomic_fetch_add' In file included from /Users/user/esp/esp-idf-v4.0-rc/components/esp_eth/src/esp_eth.c:15:0: /Users/user/esp/esp-idf-v4.0-rc/components/esp_eth/src/esp_eth.c: In function 'esp_eth_decrease_reference': /Users/user/esp/esp-idf-v4.0-rc/components/newlib/include/stdatomic.h:279:30: error: request for member '__val' in something not a structure or union __atomic_fetch_sub(&(object)->__val, operand, order) ^ /Users/user/esp/esp-idf-v4.0-rc/components/newlib/include/stdatomic.h:361:2: note: in expansion of macro 'atomic_fetch_sub_explicit' atomic_fetch_sub_explicit(object, operand, memory_order_seq_cst) ^ /Users/user/esp/esp-idf-v4.0-rc/components/esp_eth/src/esp_eth.c:352:5: note: in expansion of macro 'atomic_fetch_sub' atomic_fetch_sub(&eth_driver->ref_count, 1); ^ /Users/user/esp/esp-idf-v4.0-rc/components/esp_eth/src/esp_eth.c:352:5: error: incompatible type for argument 1 of '__atomic_fetch_sub' /Users/user/esp/esp-idf-v4.0-rc/components/esp_eth/src/esp_eth.c: At top level: cc1: warning: unrecognized command line option '-Wno-frame-address' make[2]: *** [esp-idf/esp_eth/CMakeFiles/__idf_esp_eth.dir/src/esp_eth.c.obj] Error 1 make[2]: *** Waiting for unfinished jobs.... make[1]: *** [esp-idf/esp_eth/CMakeFiles/__idf_esp_eth.dir/all] Error 2 make: *** [all] Error 2 make failed with exit code 2 — You are receiving this because you were mentioned. 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[Mras2an]

Hello,

I think I have this issue on esp-idf 4.0 with a ESP32-WROVER (8mb of RAM)

In file included from /tmp/esp-homekit-sdk/esp-idf/components/esp_eth/src/esp_eth.c:15:0:
/tmp/esp-homekit-sdk/esp-idf/components/newlib/include/stdatomic.h: In function 'atomic_flag_test_and_set_explicit':
/tmp/esp-homekit-sdk/esp-idf/components/newlib/include/stdatomic.h:271:31: error: request for member '__val' in something not a structure or union

Is there any news on it?

thank you