Re: [PATCH v2 3/3] powerpc/ps3: use put_device() on device_register() failure in ps3_system_bus_device_register
flat view
From: Sourabh Jain <hidden>
Date: 2026-08-14 02:30:50
Also in:
driver-core, linux-arm-kernel, lkml
On 13/08/26 15:24, Tarun Sahu wrote:
When device_register() fails, calling put_device() ensures that the device reference count drops to 0, which invokes the release callback ps3_system_bus_release_device() to cleanly free the device and its associated driver core resources.
Yes, since the PS3 device has a release function, put_device() should be used instead of manually freeing the memory, as described in device_register(). Changes look good to me. Feel free to add: Reviewed-by: Sourabh Jain <redacted>
quoted hunk ↗ jump to hunk
Signed-off-by: Tarun Sahu <redacted> --- arch/powerpc/platforms/ps3/device-init.c | 83 ++++++++++++++---------- arch/powerpc/platforms/ps3/system-bus.c | 2 + 2 files changed, 52 insertions(+), 33 deletions(-)diff --git a/arch/powerpc/platforms/ps3/device-init.c b/arch/powerpc/platforms/ps3/device-init.c index 9109c218a060..8d0c77db1764 100644 --- a/arch/powerpc/platforms/ps3/device-init.c +++ b/arch/powerpc/platforms/ps3/device-init.c@@ -90,14 +90,12 @@ static int __init ps3_register_lpm_devices(void) if (result) { pr_debug("%s:%d ps3_system_bus_device_register failed\n", __func__, __LINE__); - goto fail_register; + return result; } pr_debug(" <- %s:%d\n", __func__, __LINE__); return 0; - -fail_register: fail_rights: fail_read_repo: kfree(dev);@@ -121,6 +119,12 @@ static int __init ps3_setup_gelic_device( struct ps3_dma_region d_region; } *p; + /* + * ps3_system_bus_release_device() calls kfree(&p->dev). + * dev must be at offset 0 so kfree() frees outer p. + */ + BUILD_BUG_ON(offsetof(struct layout, dev) != 0); + pr_debug(" -> %s:%d\n", __func__, __LINE__); BUG_ON(repo->bus_type != PS3_BUS_TYPE_SB);@@ -164,13 +168,12 @@ static int __init ps3_setup_gelic_device( if (result) { pr_debug("%s:%d ps3_system_bus_device_register failed\n", __func__, __LINE__); - goto fail_device_register; + return result; } pr_debug(" <- %s:%d\n", __func__, __LINE__); return result; -fail_device_register: fail_dma_init: fail_find_interrupt: kfree(p);@@ -192,6 +195,12 @@ static int __init ps3_setup_uhc_device( u64 bus_addr; u64 len; + /* + * ps3_system_bus_release_device() calls kfree(&p->dev). + * dev must be at offset 0 so kfree() frees outer p. + */ + BUILD_BUG_ON(offsetof(struct layout, dev) != 0); + pr_debug(" -> %s:%d\n", __func__, __LINE__); BUG_ON(repo->bus_type != PS3_BUS_TYPE_SB);@@ -252,13 +261,12 @@ static int __init ps3_setup_uhc_device( if (result) { pr_debug("%s:%d ps3_system_bus_device_register failed\n", __func__, __LINE__); - goto fail_device_register; + return result; } pr_debug(" <- %s:%d\n", __func__, __LINE__); return result; -fail_device_register: fail_mmio_init: fail_dma_init: fail_find_reg:@@ -291,6 +299,12 @@ static int __init ps3_setup_vuart_device(enum ps3_match_id match_id, struct ps3_system_bus_device dev; } *p; + /* + * ps3_system_bus_release_device() calls kfree(&p->dev). + * dev must be at offset 0 so kfree() frees outer p. + */ + BUILD_BUG_ON(offsetof(struct layout, dev) != 0); + pr_debug(" -> %s:%d: match_id %u, port %u\n", __func__, __LINE__, match_id, port_number);@@ -308,15 +322,10 @@ static int __init ps3_setup_vuart_device(enum ps3_match_id match_id, if (result) { pr_debug("%s:%d ps3_system_bus_device_register failed\n", __func__, __LINE__); - goto fail_device_register; + return result; } pr_debug(" <- %s:%d\n", __func__, __LINE__); return 0; - -fail_device_register: - kfree(p); - pr_debug(" <- %s:%d fail\n", __func__, __LINE__); - return result; } static int ps3_setup_storage_dev(const struct ps3_repository_device *repo,@@ -327,6 +336,12 @@ static int ps3_setup_storage_dev(const struct ps3_repository_device *repo, u64 port, blk_size, num_blocks; unsigned int num_regions, i; + /* + * ps3_system_bus_release_device() calls kfree(&p->sbd). + * sbd must be at offset 0 so kfree() frees outer p. + */ + BUILD_BUG_ON(offsetof(struct ps3_storage_device, sbd) != 0); + pr_debug(" -> %s:%u: match_id %u\n", __func__, __LINE__, match_id); result = ps3_repository_read_stor_dev_info(repo->bus_index,@@ -395,13 +410,12 @@ static int ps3_setup_storage_dev(const struct ps3_repository_device *repo, if (result) { pr_debug("%s:%u ps3_system_bus_device_register failed\n", __func__, __LINE__); - goto fail_device_register; + return result; } pr_debug(" <- %s:%u\n", __func__, __LINE__); return 0; -fail_device_register: fail_read_region: fail_find_interrupt: kfree(p);@@ -445,6 +459,12 @@ static int __init ps3_register_sound_devices(void) struct ps3_mmio_region m_region; } *p; + /* + * ps3_system_bus_release_device() calls kfree(&p->dev). + * dev must be at offset 0 so kfree() frees outer p. + */ + BUILD_BUG_ON(offsetof(struct layout, dev) != 0); + pr_debug(" -> %s:%d\n", __func__, __LINE__); p = kzalloc_obj(*p);@@ -461,15 +481,10 @@ static int __init ps3_register_sound_devices(void) if (result) { pr_debug("%s:%d ps3_system_bus_device_register failed\n", __func__, __LINE__); - goto fail_device_register; + return result; } pr_debug(" <- %s:%d\n", __func__, __LINE__); return 0; - -fail_device_register: - kfree(p); - pr_debug(" <- %s:%d failed\n", __func__, __LINE__); - return result; } static int __init ps3_register_graphics_devices(void)@@ -479,6 +494,12 @@ static int __init ps3_register_graphics_devices(void) struct ps3_system_bus_device dev; } *p; + /* + * ps3_system_bus_release_device() calls kfree(&p->dev). + * dev must be at offset 0 so kfree() frees outer p. + */ + BUILD_BUG_ON(offsetof(struct layout, dev) != 0); + pr_debug(" -> %s:%d\n", __func__, __LINE__); p = kzalloc_obj(struct layout);@@ -495,16 +516,11 @@ static int __init ps3_register_graphics_devices(void) if (result) { pr_debug("%s:%d ps3_system_bus_device_register failed\n", __func__, __LINE__); - goto fail_device_register; + return result; } pr_debug(" <- %s:%d\n", __func__, __LINE__); return 0; - -fail_device_register: - kfree(p); - pr_debug(" <- %s:%d failed\n", __func__, __LINE__); - return result; } static int __init ps3_register_ramdisk_device(void)@@ -514,6 +530,12 @@ static int __init ps3_register_ramdisk_device(void) struct ps3_system_bus_device dev; } *p; + /* + * ps3_system_bus_release_device() calls kfree(&p->dev). + * dev must be at offset 0 so kfree() frees outer p. + */ + BUILD_BUG_ON(offsetof(struct layout, dev) != 0); + pr_debug(" -> %s:%d\n", __func__, __LINE__); p = kzalloc_obj(struct layout);@@ -530,16 +552,11 @@ static int __init ps3_register_ramdisk_device(void) if (result) { pr_debug("%s:%d ps3_system_bus_device_register failed\n", __func__, __LINE__); - goto fail_device_register; + return result; } pr_debug(" <- %s:%d\n", __func__, __LINE__); return 0; - -fail_device_register: - kfree(p); - pr_debug(" <- %s:%d failed\n", __func__, __LINE__); - return result; } /**diff --git a/arch/powerpc/platforms/ps3/system-bus.c b/arch/powerpc/platforms/ps3/system-bus.c index 0537a678a32f..0918c74d3e19 100644 --- a/arch/powerpc/platforms/ps3/system-bus.c +++ b/arch/powerpc/platforms/ps3/system-bus.c@@ -774,6 +774,8 @@ int ps3_system_bus_device_register(struct ps3_system_bus_device *dev) pr_debug("%s:%d add %s\n", __func__, __LINE__, dev_name(&dev->core)); result = device_register(&dev->core); + if (result) + put_device(&dev->core); return result; }