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| author | Tom Lendacky <thomas.lendacky@amd.com> | 2017-11-06 21:17:53 +0100 |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de> | 2017-11-17 15:30:33 +0100 |
| commit | ac5292e9a294618cecb31109d1ba265e3d027ba2 (patch) | |
| tree | 76e74e08320f656c0a7d860abf99f91dde7dfe31 | |
| parent | x86/mm: Limit mmap() of /dev/mem to valid physical addresses (diff) | |
| download | linux-ac5292e9a294618cecb31109d1ba265e3d027ba2.tar.xz linux-ac5292e9a294618cecb31109d1ba265e3d027ba2.zip | |
x86/boot: Fix boot failure when SMP MP-table is based at 0
When crosvm is used to boot a kernel as a VM, the SMP MP-table is found
at physical address 0x0. This causes mpf_base to be set to 0 and a
subsequent "if (!mpf_base)" check in default_get_smp_config() results in
the MP-table not being parsed. Further into the boot this results in an
oops when attempting a read_apic_id().
Add a boolean variable that is set to true when the MP-table is found.
Use this variable for testing if the MP-table was found so that even a
value of 0 for mpf_base will result in continued parsing of the MP-table.
Fixes: 5997efb96756 ("x86/boot: Use memremap() to map the MPF and MPC data")
Reported-by: Tomeu Vizoso <tomeu@tomeuvizoso.net>
Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: regression@leemhuis.info
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/20171106201753.23059.86674.stgit@tlendack-t1.amdoffice.net
| -rw-r--r-- | arch/x86/kernel/mpparse.c | 6 |
1 files changed, 4 insertions, 2 deletions
diff --git a/arch/x86/kernel/mpparse.c b/arch/x86/kernel/mpparse.c index 410c5dadcee3..3a4b12809ab5 100644 --- a/arch/x86/kernel/mpparse.c +++ b/arch/x86/kernel/mpparse.c @@ -431,6 +431,7 @@ static inline void __init construct_default_ISA_mptable(int mpc_default_type) } static unsigned long mpf_base; +static bool mpf_found; static unsigned long __init get_mpc_size(unsigned long physptr) { @@ -504,7 +505,7 @@ void __init default_get_smp_config(unsigned int early) if (!smp_found_config) return; - if (!mpf_base) + if (!mpf_found) return; if (acpi_lapic && early) @@ -593,6 +594,7 @@ static int __init smp_scan_config(unsigned long base, unsigned long length) smp_found_config = 1; #endif mpf_base = base; + mpf_found = true; pr_info("found SMP MP-table at [mem %#010lx-%#010lx] mapped at [%p]\n", base, base + sizeof(*mpf) - 1, mpf); @@ -858,7 +860,7 @@ static int __init update_mp_table(void) if (!enable_update_mptable) return 0; - if (!mpf_base) + if (!mpf_found) return 0; mpf = early_memremap(mpf_base, sizeof(*mpf)); |