From 60c8144afc287ef09ce8c1230c6aa972659ba1bb Mon Sep 17 00:00:00 2001 From: Borislav Petkov Date: Tue, 27 Nov 2018 14:41:37 +0100 Subject: [PATCH] x86/MCE/AMD: Fix the thresholding machinery initialization order MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Currently, the code sets up the thresholding interrupt vector and only then goes about initializing the thresholding banks. Which is wrong, because an early thresholding interrupt would cause a NULL pointer dereference when accessing those banks and prevent the machine from booting. Therefore, set the thresholding interrupt vector only *after* having initialized the banks successfully. Fixes: 18807ddb7f88 ("x86/mce/AMD: Reset Threshold Limit after logging error") Reported-by: Rafał Miłecki Reported-by: John Clemens Signed-off-by: Borislav Petkov Tested-by: Rafał Miłecki Tested-by: John Clemens Cc: Aravind Gopalakrishnan Cc: linux-edac@vger.kernel.org Cc: stable@vger.kernel.org Cc: Tony Luck Cc: x86@kernel.org Cc: Yazen Ghannam Link: https://lkml.kernel.org/r/20181127101700.2964-1-zajec5@gmail.com Link: https://bugzilla.kernel.org/show_bug.cgi?id=201291 --- arch/x86/kernel/cpu/mcheck/mce_amd.c | 19 ++++++------------- 1 file changed, 6 insertions(+), 13 deletions(-) diff --git a/arch/x86/kernel/cpu/mcheck/mce_amd.c b/arch/x86/kernel/cpu/mcheck/mce_amd.c index dd33c357548f..e12454e21b8a 100644 --- a/arch/x86/kernel/cpu/mcheck/mce_amd.c +++ b/arch/x86/kernel/cpu/mcheck/mce_amd.c @@ -56,7 +56,7 @@ /* Threshold LVT offset is at MSR0xC0000410[15:12] */ #define SMCA_THR_LVT_OFF 0xF000 -static bool thresholding_en; +static bool thresholding_irq_en; static const char * const th_names[] = { "load_store", @@ -534,9 +534,8 @@ prepare_threshold_block(unsigned int bank, unsigned int block, u32 addr, set_offset: offset = setup_APIC_mce_threshold(offset, new); - - if ((offset == new) && (mce_threshold_vector != amd_threshold_interrupt)) - mce_threshold_vector = amd_threshold_interrupt; + if (offset == new) + thresholding_irq_en = true; done: mce_threshold_block_init(&b, offset); @@ -1357,9 +1356,6 @@ int mce_threshold_remove_device(unsigned int cpu) { unsigned int bank; - if (!thresholding_en) - return 0; - for (bank = 0; bank < mca_cfg.banks; ++bank) { if (!(per_cpu(bank_map, cpu) & (1 << bank))) continue; @@ -1377,9 +1373,6 @@ int mce_threshold_create_device(unsigned int cpu) struct threshold_bank **bp; int err = 0; - if (!thresholding_en) - return 0; - bp = per_cpu(threshold_banks, cpu); if (bp) return 0; @@ -1408,9 +1401,6 @@ static __init int threshold_init_device(void) { unsigned lcpu = 0; - if (mce_threshold_vector == amd_threshold_interrupt) - thresholding_en = true; - /* to hit CPUs online before the notifier is up */ for_each_online_cpu(lcpu) { int err = mce_threshold_create_device(lcpu); @@ -1419,6 +1409,9 @@ static __init int threshold_init_device(void) return err; } + if (thresholding_irq_en) + mce_threshold_vector = amd_threshold_interrupt; + return 0; } /*