From: Lukas Wunner lukas@wunner.de
commit 27afac93e3bd7fa89749cf11da5d86ac9cde4dba upstream.
If probing of a pl011 gets deferred until after free_initmem(), an oops ensues because pl011_console_match() is called which has been freed.
Fix by removing the __init attribute from the function and those it calls.
Commit 10879ae5f12e ("serial: pl011: add console matching function") introduced pl011_console_match() not just for early consoles but regular preferred consoles, such as those added by acpi_parse_spcr(). Regular consoles may be registered after free_initmem() for various reasons, one being deferred probing, another being dynamic enablement of serial ports using a DeviceTree overlay.
Thus, pl011_console_match() must not be declared __init and the functions it calls mustn't either.
Stack trace for posterity:
Unable to handle kernel paging request at virtual address 80c38b58 Internal error: Oops: 8000000d [#1] PREEMPT SMP ARM PC is at pl011_console_match+0x0/0xfc LR is at register_console+0x150/0x468 [<80187004>] (register_console) [<805a8184>] (uart_add_one_port) [<805b2b68>] (pl011_register_port) [<805b3ce4>] (pl011_probe) [<80569214>] (amba_probe) [<805ca088>] (really_probe) [<805ca2ec>] (driver_probe_device) [<805ca5b0>] (__device_attach_driver) [<805c8060>] (bus_for_each_drv) [<805c9dfc>] (__device_attach) [<805ca630>] (device_initial_probe) [<805c90a8>] (bus_probe_device) [<805c95a8>] (deferred_probe_work_func)
Fixes: 10879ae5f12e ("serial: pl011: add console matching function") Signed-off-by: Lukas Wunner lukas@wunner.de Cc: stable@vger.kernel.org # v4.10+ Cc: Aleksey Makarov amakarov@marvell.com Cc: Peter Hurley peter@hurleysoftware.com Cc: Russell King linux@armlinux.org.uk Cc: Christopher Covington cov@codeaurora.org Link: https://lore.kernel.org/r/f827ff09da55b8c57d316a1b008a137677b58921.159731555... Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- drivers/tty/serial/amba-pl011.c | 11 +++++------ 1 file changed, 5 insertions(+), 6 deletions(-)
--- a/drivers/tty/serial/amba-pl011.c +++ b/drivers/tty/serial/amba-pl011.c @@ -2241,9 +2241,8 @@ pl011_console_write(struct console *co, clk_disable(uap->clk); }
-static void __init -pl011_console_get_options(struct uart_amba_port *uap, int *baud, - int *parity, int *bits) +static void pl011_console_get_options(struct uart_amba_port *uap, int *baud, + int *parity, int *bits) { if (pl011_read(uap, REG_CR) & UART01x_CR_UARTEN) { unsigned int lcr_h, ibrd, fbrd; @@ -2276,7 +2275,7 @@ pl011_console_get_options(struct uart_am } }
-static int __init pl011_console_setup(struct console *co, char *options) +static int pl011_console_setup(struct console *co, char *options) { struct uart_amba_port *uap; int baud = 38400; @@ -2344,8 +2343,8 @@ static int __init pl011_console_setup(st * * Returns 0 if console matches; otherwise non-zero to use default matching */ -static int __init pl011_console_match(struct console *co, char *name, int idx, - char *options) +static int pl011_console_match(struct console *co, char *name, int idx, + char *options) { unsigned char iotype; resource_size_t addr;