Messages in this thread | | | Date | Wed, 12 Oct 2022 17:26:09 +0200 | Subject | Re: [PATCH 1/2] x86: Check return values from early_memremap calls | From | Juergen Gross <> |
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On 12.10.22 17:13, Ross Philipson wrote: > On 10/8/22 11:12, Borislav Petkov wrote: >> Adding Xen and Jailhouse people and MLs to Cc. >> >> Folks, thread starts here: >> >> https://lore.kernel.org/r/1650035401-22855-1-git-send-email-ross.philipson@oracle.com >> >> On Fri, Apr 15, 2022 at 11:10:00AM -0400, Ross Philipson wrote: >>> There are a number of places where early_memremap is called >>> but the return pointer is not checked for NULL. The call >>> can result in a NULL being returned so the checks must >>> be added. >>> >>> Signed-off-by: Ross Philipson <ross.philipson@oracle.com> >>> --- >>> arch/x86/kernel/devicetree.c | 10 ++++++++++ >>> arch/x86/kernel/e820.c | 5 +++++ >>> arch/x86/kernel/jailhouse.c | 6 ++++++ >>> arch/x86/kernel/mpparse.c | 23 +++++++++++++++++++++++ >>> arch/x86/kernel/setup.c | 5 +++++ >>> arch/x86/xen/enlighten_hvm.c | 2 ++ >>> arch/x86/xen/mmu_pv.c | 8 ++++++++ >>> arch/x86/xen/setup.c | 2 ++ >>> 8 files changed, 61 insertions(+) >> >> Ok, a couple of notes: >> >> 1. the pr_*("<prefix>:" ... ) >> >> thing is done using pr_fmt() - grep the tree for examples. > > I am already using the pr_* macros in the patches. Are you asking me to do > something or is this just informational? > >> >> 2. I think you should not panic() the machine but issue a the >> warning/error and let the machine die a painful death anyway. But Xen >> folks will know better what would be the optimal thing to do. > > When I was working on the patches I asked Andrew Cooper at Citrix what action I > should take if any of the calls in the Xen code failed. I believe he told me it > was basically fatal and that panic() would be fine there.
panic() is the way to go. Everything else would make the error harder to analyze.
BTW, CC-ing the maintainers of the modified code is good practice.
Juergen [unhandled content-type:application/pgp-keys][unhandled content-type:application/pgp-signature] | |