2020-05-13 13:43:21

by Qian Cai

[permalink] [raw]
Subject: [PATCH] powerpc/xive: silence kmemleak false positives

opal_xive_donate_page() will reference the newly allocated memory using
__pa(). Since kmemleak is unable to track the physical memory resulting
in false positives, silence those by using kmemleak_ignore().

unreferenced object 0xc000201b53e90000 (size 65536):
comm "qemu-kvm", pid 124557, jiffies 4295650285 (age 364.370s)
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:
[<00000000acc2fb77>] xive_native_alloc_vp_block+0x168/0x210
xive_native_provision_pages at arch/powerpc/sysdev/xive/native.c:645
(inlined by) xive_native_alloc_vp_block at arch/powerpc/sysdev/xive/native.c:674
[<000000004d5c7964>] kvmppc_xive_compute_vp_id+0x20c/0x3b0 [kvm]
[<0000000055317cd2>] kvmppc_xive_connect_vcpu+0xa4/0x4a0 [kvm]
[<0000000093dfc014>] kvm_arch_vcpu_ioctl+0x388/0x508 [kvm]
[<00000000d25aea0f>] kvm_vcpu_ioctl+0x15c/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 <[email protected]>
---
arch/powerpc/sysdev/xive/native.c | 4 ++++
1 file changed, 4 insertions(+)

diff --git a/arch/powerpc/sysdev/xive/native.c b/arch/powerpc/sysdev/xive/native.c
index 5218fdc4b29a..2d19f28967a6 100644
--- a/arch/powerpc/sysdev/xive/native.c
+++ b/arch/powerpc/sysdev/xive/native.c
@@ -18,6 +18,7 @@
#include <linux/delay.h>
#include <linux/cpumask.h>
#include <linux/mm.h>
+#include <linux/kmemleak.h>

#include <asm/machdep.h>
#include <asm/prom.h>
@@ -647,6 +648,9 @@ static bool xive_native_provision_pages(void)
pr_err("Failed to allocate provisioning page\n");
return false;
}
+ /* Kmemleak is unable to track the physical address. */
+ kmemleak_ignore(p);
+
opal_xive_donate_page(chip, __pa(p));
}
return true;
--
2.21.0 (Apple Git-122.2)