6.15-stable review patch. If anyone has any objections, please let me know.
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From: Gaurav Batra gbatra@linux.ibm.com
[ Upstream commit d36e3f11fe8b55b801bdbe84ad51f612b1bd84da ]
When a device is opened by a userspace driver, via VFIO interface, DMA window is created. This DMA window has TCE Table and a corresponding data for userview of TCE table.
When the userspace driver closes the device, all the above infrastructure is free'ed and the device control given back to kernel. Both DMA window and TCE table is getting free'ed. But due to a code bug, userview of the TCE table is not getting free'ed. This is resulting in a memory leak.
Befow is the information from KMEMLEAK
unreferenced object 0xc008000022af0000 (size 16777216): comm "senlib_unit_tes", pid 9346, jiffies 4294983174 hex dump (first 32 bytes): 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ backtrace (crc 0): kmemleak_vmalloc+0xc8/0x1a0 __vmalloc_node_range+0x284/0x340 vzalloc+0x58/0x70 spapr_tce_create_table+0x4b0/0x8d0 tce_iommu_create_table+0xcc/0x170 [vfio_iommu_spapr_tce] tce_iommu_create_window+0x144/0x2f0 [vfio_iommu_spapr_tce] tce_iommu_ioctl.part.0+0x59c/0xc90 [vfio_iommu_spapr_tce] vfio_fops_unl_ioctl+0x88/0x280 [vfio] sys_ioctl+0xf4/0x160 system_call_exception+0x164/0x310 system_call_vectored_common+0xe8/0x278 unreferenced object 0xc008000023b00000 (size 4194304): comm "senlib_unit_tes", pid 9351, jiffies 4294984116 hex dump (first 32 bytes): 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ backtrace (crc 0): kmemleak_vmalloc+0xc8/0x1a0 __vmalloc_node_range+0x284/0x340 vzalloc+0x58/0x70 spapr_tce_create_table+0x4b0/0x8d0 tce_iommu_create_table+0xcc/0x170 [vfio_iommu_spapr_tce] tce_iommu_create_window+0x144/0x2f0 [vfio_iommu_spapr_tce] tce_iommu_create_default_window+0x88/0x120 [vfio_iommu_spapr_tce] tce_iommu_ioctl.part.0+0x57c/0xc90 [vfio_iommu_spapr_tce] vfio_fops_unl_ioctl+0x88/0x280 [vfio] sys_ioctl+0xf4/0x160 system_call_exception+0x164/0x310 system_call_vectored_common+0xe8/0x278
Fixes: f431a8cde7f1 ("powerpc/iommu: Reimplement the iommu_table_group_ops for pSeries") Signed-off-by: Gaurav Batra gbatra@linux.ibm.com Reviewed-by: Nilay Shroff nilay@linux.ibm.com Reviewed-by: Ritesh Harjani (IBM) ritesh.list@gmail.com Signed-off-by: Madhavan Srinivasan maddy@linux.ibm.com Link: https://patch.msgid.link/20250512224653.35697-1-gbatra@linux.ibm.com Signed-off-by: Sasha Levin sashal@kernel.org --- arch/powerpc/platforms/pseries/iommu.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/powerpc/platforms/pseries/iommu.c b/arch/powerpc/platforms/pseries/iommu.c index d6ebc19fb99c5..eec333dd2e598 100644 --- a/arch/powerpc/platforms/pseries/iommu.c +++ b/arch/powerpc/platforms/pseries/iommu.c @@ -197,7 +197,7 @@ static void tce_iommu_userspace_view_free(struct iommu_table *tbl)
static void tce_free_pSeries(struct iommu_table *tbl) { - if (!tbl->it_userspace) + if (tbl->it_userspace) tce_iommu_userspace_view_free(tbl); }