| Message ID | 20200513133915.1040-1-cai@lca.pw |
|---|---|
| State | Accepted |
| Headers | show |
| Series | powerpc/kvm/radix: ignore kmemleak false positives | expand |
On Wed, May 13, 2020 at 09:39:15AM -0400, Qian Cai wrote: > kvmppc_pmd_alloc() and kvmppc_pte_alloc() allocate some memory but then > pud_populate() and pmd_populate() will use __pa() to reference the newly > allocated memory. > > Since kmemleak is unable to track the physical memory resulting in false > positives, silence those by using kmemleak_ignore(). > > unreferenced object 0xc000201c382a1000 (size 4096): > comm "qemu-kvm", pid 124828, jiffies 4295733767 (age 341.250s) > hex dump (first 32 bytes): > c0 00 20 09 f4 60 03 87 c0 00 20 10 72 a0 03 87 .. ..`.... .r... > c0 00 20 0e 13 a0 03 87 c0 00 20 1b dc c0 03 87 .. ....... ..... > backtrace: > [<000000004cc2790f>] kvmppc_create_pte+0x838/0xd20 [kvm_hv] > kvmppc_pmd_alloc at arch/powerpc/kvm/book3s_64_mmu_radix.c:366 > (inlined by) kvmppc_create_pte at arch/powerpc/kvm/book3s_64_mmu_radix.c:590 > [<00000000d123c49a>] kvmppc_book3s_instantiate_page+0x2e0/0x8c0 [kvm_hv] > [<00000000bb549087>] kvmppc_book3s_radix_page_fault+0x1b4/0x2b0 [kvm_hv] > [<0000000086dddc0e>] kvmppc_book3s_hv_page_fault+0x214/0x12a0 [kvm_hv] > [<000000005ae9ccc2>] kvmppc_vcpu_run_hv+0xc5c/0x15f0 [kvm_hv] > [<00000000d22162ff>] kvmppc_vcpu_run+0x34/0x48 [kvm] > [<00000000d6953bc4>] kvm_arch_vcpu_ioctl_run+0x314/0x420 [kvm] > [<000000002543dd54>] kvm_vcpu_ioctl+0x33c/0x950 [kvm] > [<0000000048155cd6>] ksys_ioctl+0xd8/0x130 > [<0000000041ffeaa7>] sys_ioctl+0x28/0x40 > [<000000004afc4310>] system_call_exception+0x114/0x1e0 > [<00000000fb70a873>] system_call_common+0xf0/0x278 > unreferenced object 0xc0002001f0c03900 (size 256): > comm "qemu-kvm", pid 124830, jiffies 4295735235 (age 326.570s) > hex dump (first 32 bytes): > c0 00 20 10 fa a0 03 87 c0 00 20 10 fa a1 03 87 .. ....... ..... > c0 00 20 10 fa a2 03 87 c0 00 20 10 fa a3 03 87 .. ....... ..... > backtrace: > [<0000000023f675b8>] kvmppc_create_pte+0x854/0xd20 [kvm_hv] > kvmppc_pte_alloc at arch/powerpc/kvm/book3s_64_mmu_radix.c:356 > (inlined by) kvmppc_create_pte at arch/powerpc/kvm/book3s_64_mmu_radix.c:593 > [<00000000d123c49a>] kvmppc_book3s_instantiate_page+0x2e0/0x8c0 [kvm_hv] > [<00000000bb549087>] kvmppc_book3s_radix_page_fault+0x1b4/0x2b0 [kvm_hv] > [<0000000086dddc0e>] kvmppc_book3s_hv_page_fault+0x214/0x12a0 [kvm_hv] > [<000000005ae9ccc2>] kvmppc_vcpu_run_hv+0xc5c/0x15f0 [kvm_hv] > [<00000000d22162ff>] kvmppc_vcpu_run+0x34/0x48 [kvm] > [<00000000d6953bc4>] kvm_arch_vcpu_ioctl_run+0x314/0x420 [kvm] > [<000000002543dd54>] kvm_vcpu_ioctl+0x33c/0x950 [kvm] > [<0000000048155cd6>] ksys_ioctl+0xd8/0x130 > [<0000000041ffeaa7>] sys_ioctl+0x28/0x40 > [<000000004afc4310>] system_call_exception+0x114/0x1e0 > [<00000000fb70a873>] system_call_common+0xf0/0x278 > > Signed-off-by: Qian Cai <cai@lca.pw> Thanks, applied to my kvm-ppc-next branch. Paul.
diff --git a/arch/powerpc/kvm/book3s_64_mmu_radix.c b/arch/powerpc/kvm/book3s_64_mmu_radix.c index aa12cd4078b3..bc6c1aa3d0e9 100644 --- a/arch/powerpc/kvm/book3s_64_mmu_radix.c +++ b/arch/powerpc/kvm/book3s_64_mmu_radix.c @@ -353,7 +353,13 @@ static struct kmem_cache *kvm_pmd_cache; static pte_t *kvmppc_pte_alloc(void) { - return kmem_cache_alloc(kvm_pte_cache, GFP_KERNEL); + pte_t *pte; + + pte = kmem_cache_alloc(kvm_pte_cache, GFP_KERNEL); + /* pmd_populate() will only reference _pa(pte). */ + kmemleak_ignore(pte); + + return pte; } static void kvmppc_pte_free(pte_t *ptep) @@ -363,7 +369,13 @@ static void kvmppc_pte_free(pte_t *ptep) static pmd_t *kvmppc_pmd_alloc(void) { - return kmem_cache_alloc(kvm_pmd_cache, GFP_KERNEL); + pmd_t *pmd; + + pmd = kmem_cache_alloc(kvm_pmd_cache, GFP_KERNEL); + /* pud_populate() will only reference _pa(pmd). */ + kmemleak_ignore(pmd); + + return pmd; } static void kvmppc_pmd_free(pmd_t *pmdp)
kvmppc_pmd_alloc() and kvmppc_pte_alloc() allocate some memory but then pud_populate() and pmd_populate() will use __pa() to reference the newly allocated memory. Since kmemleak is unable to track the physical memory resulting in false positives, silence those by using kmemleak_ignore(). unreferenced object 0xc000201c382a1000 (size 4096): comm "qemu-kvm", pid 124828, jiffies 4295733767 (age 341.250s) hex dump (first 32 bytes): c0 00 20 09 f4 60 03 87 c0 00 20 10 72 a0 03 87 .. ..`.... .r... c0 00 20 0e 13 a0 03 87 c0 00 20 1b dc c0 03 87 .. ....... ..... backtrace: [<000000004cc2790f>] kvmppc_create_pte+0x838/0xd20 [kvm_hv] kvmppc_pmd_alloc at arch/powerpc/kvm/book3s_64_mmu_radix.c:366 (inlined by) kvmppc_create_pte at arch/powerpc/kvm/book3s_64_mmu_radix.c:590 [<00000000d123c49a>] kvmppc_book3s_instantiate_page+0x2e0/0x8c0 [kvm_hv] [<00000000bb549087>] kvmppc_book3s_radix_page_fault+0x1b4/0x2b0 [kvm_hv] [<0000000086dddc0e>] kvmppc_book3s_hv_page_fault+0x214/0x12a0 [kvm_hv] [<000000005ae9ccc2>] kvmppc_vcpu_run_hv+0xc5c/0x15f0 [kvm_hv] [<00000000d22162ff>] kvmppc_vcpu_run+0x34/0x48 [kvm] [<00000000d6953bc4>] kvm_arch_vcpu_ioctl_run+0x314/0x420 [kvm] [<000000002543dd54>] kvm_vcpu_ioctl+0x33c/0x950 [kvm] [<0000000048155cd6>] ksys_ioctl+0xd8/0x130 [<0000000041ffeaa7>] sys_ioctl+0x28/0x40 [<000000004afc4310>] system_call_exception+0x114/0x1e0 [<00000000fb70a873>] system_call_common+0xf0/0x278 unreferenced object 0xc0002001f0c03900 (size 256): comm "qemu-kvm", pid 124830, jiffies 4295735235 (age 326.570s) hex dump (first 32 bytes): c0 00 20 10 fa a0 03 87 c0 00 20 10 fa a1 03 87 .. ....... ..... c0 00 20 10 fa a2 03 87 c0 00 20 10 fa a3 03 87 .. ....... ..... backtrace: [<0000000023f675b8>] kvmppc_create_pte+0x854/0xd20 [kvm_hv] kvmppc_pte_alloc at arch/powerpc/kvm/book3s_64_mmu_radix.c:356 (inlined by) kvmppc_create_pte at arch/powerpc/kvm/book3s_64_mmu_radix.c:593 [<00000000d123c49a>] kvmppc_book3s_instantiate_page+0x2e0/0x8c0 [kvm_hv] [<00000000bb549087>] kvmppc_book3s_radix_page_fault+0x1b4/0x2b0 [kvm_hv] [<0000000086dddc0e>] kvmppc_book3s_hv_page_fault+0x214/0x12a0 [kvm_hv] [<000000005ae9ccc2>] kvmppc_vcpu_run_hv+0xc5c/0x15f0 [kvm_hv] [<00000000d22162ff>] kvmppc_vcpu_run+0x34/0x48 [kvm] [<00000000d6953bc4>] kvm_arch_vcpu_ioctl_run+0x314/0x420 [kvm] [<000000002543dd54>] kvm_vcpu_ioctl+0x33c/0x950 [kvm] [<0000000048155cd6>] ksys_ioctl+0xd8/0x130 [<0000000041ffeaa7>] sys_ioctl+0x28/0x40 [<000000004afc4310>] system_call_exception+0x114/0x1e0 [<00000000fb70a873>] system_call_common+0xf0/0x278 Signed-off-by: Qian Cai <cai@lca.pw> --- arch/powerpc/kvm/book3s_64_mmu_radix.c | 16 ++++++++++++++-- 1 file changed, 14 insertions(+), 2 deletions(-)