[cadcdev-svn-commits] [SCM] branch master updated. 3348accdbc8a4869ef6eeaf7799067d84af64466

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- Log -----------------------------------------------------------------
commit 3348accdbc8a4869ef6eeaf7799067d84af64466
Author: Paul Cercueil <pa...@cr...>
Date:   Mon Sep 15 19:11:08 2025 +0200

    maple: Fix race between driver attach and vblank irq
    
    The device at unit 0 is probed using a shared frame dedicated to device
    detection; devices at unit > 0 are probed using the frame of the unit 0.
    
    This means that as soon as a unit 0 device is registered, its frame can
    be used to auto-detect itself (if previously unplugged) or its children.
    
    Therefore, prior to registering a unit 0 device into the device table,
    we must ensure that all fields have been properly initialized, or we
    will race with the vblank interrupt handler.
    
    Signed-off-by: Paul Cercueil <pa...@cr...>

-----------------------------------------------------------------------

Summary of changes:
 kernel/arch/dreamcast/hardware/maple/maple_driver.c | 12 +++++++++---
 1 file changed, 9 insertions(+), 3 deletions(-)

diff --git a/kernel/arch/dreamcast/hardware/maple/maple_driver.c b/kernel/arch/dreamcast/hardware/maple/maple_driver.c
index 00b9ba0b..f84468d6 100644
--- a/kernel/arch/dreamcast/hardware/maple/maple_driver.c
+++ b/kernel/arch/dreamcast/hardware/maple/maple_driver.c
@@ -73,6 +73,7 @@ int maple_driver_attach(maple_frame_t *det) {
     maple_devinfo_t     *devinfo;
     maple_device_t      *dev = maple_state.ports[det->dst_port].units[det->dst_unit];
     bool                attached = false;
+    bool                dev_allocated = false;
 
     /* Resolve some pointers first */
     resp = (maple_response_t *)det->recv_buf;
@@ -89,12 +90,11 @@ int maple_driver_attach(maple_frame_t *det) {
                 if(!dev)
                     return 1;
 
-                maple_state.ports[det->dst_port].units[det->dst_unit] = dev;
-
                 /* Add the basics for the initial version of the struct */
                 dev->port = det->dst_port;
                 dev->unit = det->dst_unit;
                 dev->frame.state = MAPLE_FRAME_VACANT;
+                dev_allocated = true;
             }
 
             memcpy(&dev->info, devinfo, sizeof(maple_devinfo_t));
@@ -102,10 +102,16 @@ int maple_driver_attach(maple_frame_t *det) {
             /* Now lets allocate a new status buffer */
             if(i->status_size && !dev->status) {
                 dev->status = calloc(1, i->status_size);
-                if(!dev->status)
+                if(!dev->status) {
+                    if(dev_allocated)
+                        free(dev);
                     return 1;
+                }
             }
 
+            if(dev_allocated)
+                maple_state.ports[det->dst_port].units[det->dst_unit] = dev;
+
             if(!i->status_size || dev->status) {
                 /* Try to attach if we need to then break out. */
                 if(!(i->attach) || (i->attach(i, dev) >= 0)) {


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