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| author | Elena Reshetova <elena.reshetova@intel.com> | 2017-05-19 11:39:13 +0200 |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de> | 2017-05-21 21:55:13 +0200 |
| commit | 473e90b2e8356f084dcf9c815a5170d4d4925897 (patch) | |
| tree | 59e060264aa0a1d6c3cc32a04dba8170bdceca56 | |
| parent | 5f0744e50db1628d6de770b92278445b3de2779f (diff) | |
| download | linux-473e90b2e8356f084dcf9c815a5170d4d4925897.tar.gz linux-473e90b2e8356f084dcf9c815a5170d4d4925897.tar.bz2 linux-473e90b2e8356f084dcf9c815a5170d4d4925897.zip | |
x86/mce: Convert threshold_bank.cpus from atomic_t to refcount_t
The refcount_t type and corresponding API should be used instead
of atomic_t when the variable is used as a reference counter. This
allows to avoid accidental refcounter overflows that might lead to
use-after-free situations.
Suggested-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Elena Reshetova <elena.reshetova@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Hans Liljestrand <ishkamiel@gmail.com>
Reviewed-by: David Windsor <dwindsor@gmail.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Yazen Ghannam <Yazen.Ghannam@amd.com>
Cc: linux-edac <linux-edac@vger.kernel.org>
Link: http://lkml.kernel.org/r/1492695536-5947-1-git-send-email-elena.reshetova@intel.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| -rw-r--r-- | arch/x86/include/asm/amd_nb.h | 3 | ||||
| -rw-r--r-- | arch/x86/kernel/cpu/mcheck/mce_amd.c | 6 |
2 files changed, 5 insertions, 4 deletions
diff --git a/arch/x86/include/asm/amd_nb.h b/arch/x86/include/asm/amd_nb.h index 00c88a01301d..da181ad1d5f8 100644 --- a/arch/x86/include/asm/amd_nb.h +++ b/arch/x86/include/asm/amd_nb.h @@ -3,6 +3,7 @@ #include <linux/ioport.h> #include <linux/pci.h> +#include <linux/refcount.h> struct amd_nb_bus_dev_range { u8 bus; @@ -55,7 +56,7 @@ struct threshold_bank { struct threshold_block *blocks; /* initialized to the number of CPUs on the node sharing this bank */ - atomic_t cpus; + refcount_t cpus; }; struct amd_northbridge { diff --git a/arch/x86/kernel/cpu/mcheck/mce_amd.c b/arch/x86/kernel/cpu/mcheck/mce_amd.c index 6e4a047e4b68..41439ab41102 100644 --- a/arch/x86/kernel/cpu/mcheck/mce_amd.c +++ b/arch/x86/kernel/cpu/mcheck/mce_amd.c @@ -1202,7 +1202,7 @@ static int threshold_create_bank(unsigned int cpu, unsigned int bank) goto out; per_cpu(threshold_banks, cpu)[bank] = b; - atomic_inc(&b->cpus); + refcount_inc(&b->cpus); err = __threshold_add_blocks(b); @@ -1225,7 +1225,7 @@ static int threshold_create_bank(unsigned int cpu, unsigned int bank) per_cpu(threshold_banks, cpu)[bank] = b; if (is_shared_bank(bank)) { - atomic_set(&b->cpus, 1); + refcount_set(&b->cpus, 1); /* nb is already initialized, see above */ if (nb) { @@ -1289,7 +1289,7 @@ static void threshold_remove_bank(unsigned int cpu, int bank) goto free_out; if (is_shared_bank(bank)) { - if (!atomic_dec_and_test(&b->cpus)) { + if (!refcount_dec_and_test(&b->cpus)) { __threshold_remove_blocks(b); per_cpu(threshold_banks, cpu)[bank] = NULL; return; |