linux-kernel - Indicated kmemleak in msr_build_context() for Kernel 5.7.0-rc5

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Message-ID: <9f1bb619-c4ee-21c4-a251-870bd4db04fa@lwfinger.net>
Date:   Mon, 18 May 2020 14:21:02 -0500
From:   Larry Finger <Larry.Finger@...inger.net>
To:     LKML <linux-kernel@...r.kernel.org>
Subject: Indicated kmemleak in msr_build_context() for Kernel 5.7.0-rc5

On a system with an AMD FX-8320E Eight-Core Processor running kernel 5.7.0-rc5, 
I am seeing the following memory leak:

localhost:~ # cat /sys/kernel/debug/kmemleak
unreferenced object 0xffff88840ca02540 (size 64):
   comm "swapper/0", pid 1, jiffies 4294892775 (age 138786.084s)
   hex dump (first 32 bytes):
     00 00 00 00 00 00 00 00 04 10 01 c0 00 00 00 00  ................
     00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
   backtrace:
     [<0000000005004530>] msr_build_context.constprop.0+0x32/0xbe
     [<00000000bb4e1265>] msr_save_cpuid_features+0x28/0x2c
     [<0000000011ec0f08>] pm_check_save_msr+0x2e/0x40
     [<000000000cd50945>] do_one_initcall+0x46/0x220
     [<00000000fd0d2fc9>] kernel_init_freeable+0x1c6/0x23f
     [<000000009f9b95ca>] kernel_init+0xa/0xfc
     [<000000000a571fca>] ret_from_fork+0x22/0x40

This is a "family 0x15" AMD CPU, thus MSR saving is needed during suspending. I 
believe this to be a false positive.

The indicated memory allocation has been in the kernel since v4.5.0. Should a 
patch be sent to clear this false memory leak indication for systems with AMD 
processors?

Larry