serial: icom: Fix namespace collision and startup() section placement with -ffunction...

When compiled with -ffunction-sections (e.g., for LTO, livepatch, dead
code elimination, AutoFDO, or Propeller), the startup() function gets
compiled into the .text.startup section (or in some cases
.text.startup.constprop.0 or .text.startup.isra.0).

However, the .text.startup and .text.startup.* sections are also used by
the compiler for __attribute__((constructor)) code.

This naming conflict causes the vmlinux linker script to wrongly place
startup() function code in .init.text, which gets freed during boot.

Some builds have a mix of objects, both with and without
-ffunctions-sections, so it's not possible for the linker script to
disambiguate with #ifdef CONFIG_FUNCTION_SECTIONS or similar.  This
means that "startup" unfortunately needs to be prohibited as a function
name.

Rename startup() to icom_startup().  For consistency, also rename its
shutdown() counterpart to icom_shutdown().

Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://patch.msgid.link/1aee9ef69f9d40405676712b34f0c397706e7023.1763669451.git.jpoimboe@kernel.org

diff --git a/drivers/tty/serial/icom.c b/drivers/tty/serial/icom.c
index 7fb995a8490e12f81d986699af09bf74c58c39c8..d00903cfa841decdd18b2e10d29abf418c63d775 100644 (file)
--- a/drivers/tty/serial/icom.c
+++ b/drivers/tty/serial/icom.c
@@ -760,7 +760,7 @@ static void load_code(struct icom_port *icom_port)
                dma_free_coherent(&dev->dev, 4096, new_page, temp_pci);
 }
 
-static int startup(struct icom_port *icom_port)
+static int icom_startup(struct icom_port *icom_port)
 {
        unsigned long temp;
        unsigned char cable_id, raw_cable_id;
@@ -832,7 +832,7 @@ unlock:
        return 0;
 }
 
-static void shutdown(struct icom_port *icom_port)
+static void icom_shutdown(struct icom_port *icom_port)
 {
        unsigned long temp;
        unsigned char cmdReg;
@@ -1311,7 +1311,7 @@ static int icom_open(struct uart_port *port)
        int retval;
 
        kref_get(&icom_port->adapter->kref);
-       retval = startup(icom_port);
+       retval = icom_startup(icom_port);
 
        if (retval) {
                kref_put(&icom_port->adapter->kref, icom_kref_release);
@@ -1333,7 +1333,7 @@ static void icom_close(struct uart_port *port)
        cmdReg = readb(&icom_port->dram->CmdReg);
        writeb(cmdReg & ~CMD_RCV_ENABLE, &icom_port->dram->CmdReg);
 
-       shutdown(icom_port);
+       icom_shutdown(icom_port);
 
        kref_put(&icom_port->adapter->kref, icom_kref_release);
 }