Depmod fails for a kernel made with: make allnoconfig echo -e "CONFIG_MODULES=y\nCONFIG_SERIAL_8250=m\nCONFIG_SERIAL_8250_EXTENDED=y\nCONFIG_SERIAL_8250_RSA=y" >> .config make olddefconfig
...due to a dependency loop:
depmod: ERROR: Cycle detected: 8250 -> 8250_base -> 8250 depmod: ERROR: Found 2 modules in dependency cycles!
This is caused by the move of 8250 RSA code from 8250_port.c (in 8250_base.ko) into 8250_rsa.c (in 8250.ko) by the commit 5a128fb475fb ("serial: 8250: move RSA functions to 8250_rsa.c"). The commit b20d6576cdb3 ("serial: 8250: export RSA functions") tried to fix a missing symbol issue with EXPORTs but those then cause this dependency cycle.
Break dependency loop by moving 8250_rsa.o from 8250.ko to 8250_base.ko and by passing univ8250_port_base_ops to univ8250_rsa_support() that can make a local copy of it.
Reported-by: Stephen Rothwell sfr@canb.auug.org.au Reported-by: Alex Davis alex47794@gmail.com Fixes: 5a128fb475fb ("serial: 8250: move RSA functions to 8250_rsa.c") Fixes: b20d6576cdb3 ("serial: 8250: export RSA functions") Cc: stable@vger.kernel.org Link: https://lore.kernel.org/all/87frc3sd8d.fsf@posteo.net/ Link: https://lore.kernel.org/all/CADiockCvM6v+d+UoFZpJSMoLAdpy99_h-hJdzUsdfaWGn3W... Reviewed-by: Andy Shevchenko andriy.shevchenko@linux.intel.com Reviewed-by: Jiri Slaby jirislaby@kernel.org Signed-off-by: Ilpo Järvinen ilpo.jarvinen@linux.intel.com ---
in thread -> v1: - Changed prototype also in the #else block
drivers/tty/serial/8250/8250.h | 4 ++-- drivers/tty/serial/8250/8250_platform.c | 2 +- drivers/tty/serial/8250/8250_rsa.c | 26 ++++++++++++++++--------- drivers/tty/serial/8250/Makefile | 2 +- 4 files changed, 21 insertions(+), 13 deletions(-)
diff --git a/drivers/tty/serial/8250/8250.h b/drivers/tty/serial/8250/8250.h index 58e64c4e1e3a..e99f5193d8f1 100644 --- a/drivers/tty/serial/8250/8250.h +++ b/drivers/tty/serial/8250/8250.h @@ -322,13 +322,13 @@ static inline void serial8250_pnp_exit(void) { } #endif
#ifdef CONFIG_SERIAL_8250_RSA -void univ8250_rsa_support(struct uart_ops *ops); +void univ8250_rsa_support(struct uart_ops *ops, const struct uart_ops *core_ops); void rsa_enable(struct uart_8250_port *up); void rsa_disable(struct uart_8250_port *up); void rsa_autoconfig(struct uart_8250_port *up); void rsa_reset(struct uart_8250_port *up); #else -static inline void univ8250_rsa_support(struct uart_ops *ops) { } +static inline void univ8250_rsa_support(struct uart_ops *ops, const struct uart_ops *core_ops) { } static inline void rsa_enable(struct uart_8250_port *up) {} static inline void rsa_disable(struct uart_8250_port *up) {} static inline void rsa_autoconfig(struct uart_8250_port *up) {} diff --git a/drivers/tty/serial/8250/8250_platform.c b/drivers/tty/serial/8250/8250_platform.c index b27981340e76..fe7ec440ffa5 100644 --- a/drivers/tty/serial/8250/8250_platform.c +++ b/drivers/tty/serial/8250/8250_platform.c @@ -75,7 +75,7 @@ static void __init __serial8250_isa_init_ports(void)
/* chain base port ops to support Remote Supervisor Adapter */ univ8250_port_ops = *univ8250_port_base_ops; - univ8250_rsa_support(&univ8250_port_ops); + univ8250_rsa_support(&univ8250_port_ops, univ8250_port_base_ops);
if (share_irqs) irqflag = IRQF_SHARED; diff --git a/drivers/tty/serial/8250/8250_rsa.c b/drivers/tty/serial/8250/8250_rsa.c index 40a3dbd9e452..1f182f165525 100644 --- a/drivers/tty/serial/8250/8250_rsa.c +++ b/drivers/tty/serial/8250/8250_rsa.c @@ -14,6 +14,8 @@ static unsigned long probe_rsa[PORT_RSA_MAX]; static unsigned int probe_rsa_count;
+static const struct uart_ops *core_port_base_ops; + static int rsa8250_request_resource(struct uart_8250_port *up) { struct uart_port *port = &up->port; @@ -67,7 +69,7 @@ static void univ8250_config_port(struct uart_port *port, int flags) } }
- univ8250_port_base_ops->config_port(port, flags); + core_port_base_ops->config_port(port, flags);
if (port->type != PORT_RSA && up->probe & UART_PROBE_RSA) rsa8250_release_resource(up); @@ -78,11 +80,11 @@ static int univ8250_request_port(struct uart_port *port) struct uart_8250_port *up = up_to_u8250p(port); int ret;
- ret = univ8250_port_base_ops->request_port(port); + ret = core_port_base_ops->request_port(port); if (ret == 0 && port->type == PORT_RSA) { ret = rsa8250_request_resource(up); if (ret < 0) - univ8250_port_base_ops->release_port(port); + core_port_base_ops->release_port(port); }
return ret; @@ -94,15 +96,25 @@ static void univ8250_release_port(struct uart_port *port)
if (port->type == PORT_RSA) rsa8250_release_resource(up); - univ8250_port_base_ops->release_port(port); + core_port_base_ops->release_port(port); }
-void univ8250_rsa_support(struct uart_ops *ops) +/* + * It is not allowed to directly reference any symbols from 8250.ko here as + * that would result in a dependency loop between the 8250.ko and + * 8250_base.ko modules. This function is called from 8250.ko and is used to + * break the symbolic dependency cycle. Anything that is needed from 8250.ko + * has to be passed as pointers to this function which then can adjust those + * variables on 8250.ko side or store them locally as needed. + */ +void univ8250_rsa_support(struct uart_ops *ops, const struct uart_ops *core_ops) { + core_port_base_ops = core_ops; ops->config_port = univ8250_config_port; ops->request_port = univ8250_request_port; ops->release_port = univ8250_release_port; } +EXPORT_SYMBOL_FOR_MODULES(univ8250_rsa_support, "8250");
module_param_hw_array(probe_rsa, ulong, ioport, &probe_rsa_count, 0444); MODULE_PARM_DESC(probe_rsa, "Probe I/O ports for RSA"); @@ -146,7 +158,6 @@ void rsa_enable(struct uart_8250_port *up) if (up->port.uartclk == SERIAL_RSA_BAUD_BASE * 16) serial_out(up, UART_RSA_FRR, 0); } -EXPORT_SYMBOL_FOR_MODULES(rsa_enable, "8250_base");
/* * Attempts to turn off the RSA FIFO and resets the RSA board back to 115kbps compat mode. It is @@ -178,7 +189,6 @@ void rsa_disable(struct uart_8250_port *up) if (result) up->port.uartclk = SERIAL_RSA_BAUD_BASE_LO * 16; } -EXPORT_SYMBOL_FOR_MODULES(rsa_disable, "8250_base");
void rsa_autoconfig(struct uart_8250_port *up) { @@ -191,7 +201,6 @@ void rsa_autoconfig(struct uart_8250_port *up) if (__rsa_enable(up)) up->port.type = PORT_RSA; } -EXPORT_SYMBOL_FOR_MODULES(rsa_autoconfig, "8250_base");
void rsa_reset(struct uart_8250_port *up) { @@ -200,7 +209,6 @@ void rsa_reset(struct uart_8250_port *up)
serial_out(up, UART_RSA_FRR, 0); } -EXPORT_SYMBOL_FOR_MODULES(rsa_reset, "8250_base");
#ifdef CONFIG_SERIAL_8250_DEPRECATED_OPTIONS #ifndef MODULE diff --git a/drivers/tty/serial/8250/Makefile b/drivers/tty/serial/8250/Makefile index 513a0941c284..9ec4d5fe64de 100644 --- a/drivers/tty/serial/8250/Makefile +++ b/drivers/tty/serial/8250/Makefile @@ -7,7 +7,6 @@ obj-$(CONFIG_SERIAL_8250) += 8250.o 8250-y := 8250_core.o 8250-y += 8250_platform.o 8250-$(CONFIG_SERIAL_8250_PNP) += 8250_pnp.o -8250-$(CONFIG_SERIAL_8250_RSA) += 8250_rsa.o
obj-$(CONFIG_SERIAL_8250) += 8250_base.o 8250_base-y := 8250_port.o @@ -15,6 +14,7 @@ obj-$(CONFIG_SERIAL_8250) += 8250_base.o 8250_base-$(CONFIG_SERIAL_8250_DWLIB) += 8250_dwlib.o 8250_base-$(CONFIG_SERIAL_8250_FINTEK) += 8250_fintek.o 8250_base-$(CONFIG_SERIAL_8250_PCILIB) += 8250_pcilib.o +8250_base-$(CONFIG_SERIAL_8250_RSA) += 8250_rsa.o
obj-$(CONFIG_SERIAL_8250_CONSOLE) += 8250_early.o
base-commit: 719f3df3e113e03d2c8cf324827da1fd17a9bd8f