summaryrefslogtreecommitdiffstats
path: root/arch/x86/lib/msr.c
diff options
context:
space:
mode:
authorKees Cook <kees+treewide@kernel.org>2026-09-02 15:31:14 -0700
committerKees Cook <kees@kernel.org>2026-09-04 21:37:00 -0700
commit3a2c4d55e32ad65efebdb6de44eef3bfa08bb49d (patch)
treec65086f9bdcd48c6360fb7cb4598bca084da1f32 /arch/x86/lib/msr.c
downloadlinux-stable-3a2c4d55e32ad65efebdb6de44eef3bfa08bb49d.tar.gz
linux-stable-3a2c4d55e32ad65efebdb6de44eef3bfa08bb49d.zip
treewide: refresh kmalloc_obj() conversionsgrafted
This is another run of the Coccinelle script for converting kmalloc() family of allocations to kmalloc_obj() via the existing rules in scripts/coccinelle/api/kmalloc_objs.cocci This catches both the set of kmalloc() uses added since the first kmalloc_obj() conversions in v7.0 and adds a large group missed in the first pass due to Coccinelle not interacting well with the cleanup.h scoped_...() family of macros[1]. I worked around this with spatch's "--macro-file" argument to a file with all the scoped_...() macros mapped to Coccinelle's YACFE_ITERATOR[2] as that was the closest viable control flow indicator I could find. Build tested allmodconfig on x86, arm64, arm, loongarch, mips, powerpc, riscv, and s390 with no new warnings. Link: https://lore.kernel.org/lkml/202609021314.8A9C0B8@keescook/ [1] Link: https://github.com/coccinelle/coccinelle/blob/master/standard.h [2] Signed-off-by: Kees Cook <kees+treewide@kernel.org>
Diffstat (limited to 'arch/x86/lib/msr.c')
-rw-r--r--arch/x86/lib/msr.c147
1 files changed, 147 insertions, 0 deletions
diff --git a/arch/x86/lib/msr.c b/arch/x86/lib/msr.c
new file mode 100644
index 000000000..dfdd1da89
--- /dev/null
+++ b/arch/x86/lib/msr.c
@@ -0,0 +1,147 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <linux/export.h>
+#include <linux/kvm_types.h>
+#include <linux/percpu.h>
+#include <linux/preempt.h>
+#include <asm/msr.h>
+#define CREATE_TRACE_POINTS
+#include <asm/msr-trace.h>
+
+struct msr __percpu *msrs_alloc(void)
+{
+ struct msr __percpu *msrs = NULL;
+
+ msrs = alloc_percpu(struct msr);
+ if (!msrs) {
+ pr_warn("%s: error allocating msrs\n", __func__);
+ return NULL;
+ }
+
+ return msrs;
+}
+EXPORT_SYMBOL(msrs_alloc);
+
+void msrs_free(struct msr __percpu *msrs)
+{
+ free_percpu(msrs);
+}
+EXPORT_SYMBOL(msrs_free);
+
+/**
+ * msr_read - Read an MSR with error handling
+ * @msr: MSR to read
+ * @m: value to read into
+ *
+ * It returns read data only on success, otherwise it doesn't change the output
+ * argument @m.
+ *
+ * Return: %0 for success, otherwise an error code
+ */
+static int msr_read(u32 msr, struct msr *m)
+{
+ int err;
+ u64 val;
+
+ err = rdmsrq_safe(msr, &val);
+ if (!err)
+ m->q = val;
+
+ return err;
+}
+
+/**
+ * msr_write - Write an MSR with error handling
+ *
+ * @msr: MSR to write
+ * @m: value to write
+ *
+ * Return: %0 for success, otherwise an error code
+ */
+static int msr_write(u32 msr, struct msr *m)
+{
+ return wrmsrq_safe(msr, m->q);
+}
+
+static inline int __flip_bit(u32 msr, u8 bit, bool set)
+{
+ struct msr m, m1;
+ int err = -EINVAL;
+
+ if (bit > 63)
+ return err;
+
+ err = msr_read(msr, &m);
+ if (err)
+ return err;
+
+ m1 = m;
+ if (set)
+ m1.q |= BIT_64(bit);
+ else
+ m1.q &= ~BIT_64(bit);
+
+ if (m1.q == m.q)
+ return 0;
+
+ err = msr_write(msr, &m1);
+ if (err)
+ return err;
+
+ return 1;
+}
+
+/**
+ * msr_set_bit - Set @bit in a MSR @msr.
+ * @msr: MSR to write
+ * @bit: bit number to set
+ *
+ * Return:
+ * * < 0: An error was encountered.
+ * * = 0: Bit was already set.
+ * * > 0: Hardware accepted the MSR write.
+ */
+int msr_set_bit(u32 msr, u8 bit)
+{
+ return __flip_bit(msr, bit, true);
+}
+EXPORT_SYMBOL_FOR_KVM(msr_set_bit);
+
+/**
+ * msr_clear_bit - Clear @bit in a MSR @msr.
+ * @msr: MSR to write
+ * @bit: bit number to clear
+ *
+ * Return:
+ * * < 0: An error was encountered.
+ * * = 0: Bit was already cleared.
+ * * > 0: Hardware accepted the MSR write.
+ */
+int msr_clear_bit(u32 msr, u8 bit)
+{
+ return __flip_bit(msr, bit, false);
+}
+EXPORT_SYMBOL_FOR_KVM(msr_clear_bit);
+
+#ifdef CONFIG_TRACEPOINTS
+void do_trace_write_msr(u32 msr, u64 val, int failed)
+{
+ trace_write_msr(msr, val, failed);
+}
+EXPORT_SYMBOL(do_trace_write_msr);
+EXPORT_TRACEPOINT_SYMBOL(write_msr);
+
+void do_trace_read_msr(u32 msr, u64 val, int failed)
+{
+ trace_read_msr(msr, val, failed);
+}
+EXPORT_SYMBOL(do_trace_read_msr);
+EXPORT_TRACEPOINT_SYMBOL(read_msr);
+
+void do_trace_rdpmc(u32 msr, u64 val, int failed)
+{
+ trace_rdpmc(msr, val, failed);
+}
+EXPORT_SYMBOL(do_trace_rdpmc);
+EXPORT_TRACEPOINT_SYMBOL(rdpmc);
+
+#endif