2023-06-25 07:58:58

by Like Xu

Subject: [PATCH] KVM: x86: Use sysfs_emit() instead of sprintf()

From: Like Xu <[email protected]>

Use sysfs_emit() instead of the sprintf() for sysfs entries. sysfs_emit()
knows the maximum of the temporary buffer used for outputting sysfs
content and avoids overrunning the buffer length.

Signed-off-by: Like Xu <[email protected]>
---
arch/x86/kvm/mmu/mmu.c | 2 +-
arch/x86/kvm/vmx/vmx.c | 4 ++--
2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c
index 60397a1beda3..78f6f816c7d1 100644
--- a/arch/x86/kvm/mmu/mmu.c
+++ b/arch/x86/kvm/mmu/mmu.c
@@ -6862,7 +6862,7 @@ static void mmu_destroy_caches(void)
static int get_nx_huge_pages(char *buffer, const struct kernel_param *kp)
{
if (nx_hugepage_mitigation_hard_disabled)
- return sprintf(buffer, "never\n");
+ return sysfs_emit(buffer, "never\n");

return param_get_bool(buffer, kp);
}
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index 0ecf4be2c6af..254f2296e549 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -366,9 +366,9 @@ static int vmentry_l1d_flush_set(const char *s, const struct kernel_param *kp)
static int vmentry_l1d_flush_get(char *s, const struct kernel_param *kp)
{
if (WARN_ON_ONCE(l1tf_vmx_mitigation >= ARRAY_SIZE(vmentry_l1d_param)))
- return sprintf(s, "???\n");
+ return sysfs_emit(s, "???\n");

- return sprintf(s, "%s\n", vmentry_l1d_param[l1tf_vmx_mitigation].option);
+ return sysfs_emit(s, "%s\n", vmentry_l1d_param[l1tf_vmx_mitigation].option);
}

static void vmx_setup_fb_clear_ctrl(void)
--
2.41.0

2023-08-02 19:42:06

by Sean Christopherson

Subject: Re: [PATCH] KVM: x86: Use sysfs_emit() instead of sprintf()

On Sun, 25 Jun 2023 15:34:38 +0800, Like Xu wrote:
> Use sysfs_emit() instead of the sprintf() for sysfs entries. sysfs_emit()
> knows the maximum of the temporary buffer used for outputting sysfs
> content and avoids overrunning the buffer length.
>
>

Applied to kvm-x86 misc, thanks!

[1/1] KVM: x86: Use sysfs_emit() instead of sprintf()
https://github.com/kvm-x86/linux/commit/1d6664fadda3

--
https://github.com/kvm-x86/linux/tree/next
https://github.com/kvm-x86/linux/tree/fixes