Commit 6f0960a7 authored by David Kaplan's avatar David Kaplan Committed by Borislav Petkov (AMD)
Browse files

x86/bugs: Remove md_clear_*_mitigation() 



The functionality in md_clear_update_mitigation() and
md_clear_select_mitigation() is now integrated into the select/update
functions for the MDS, TAA, MMIO, and RFDS vulnerabilities.

Signed-off-by: default avatarDavid Kaplan <david.kaplan@amd.com>
Signed-off-by: default avatarBorislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: default avatarJosh Poimboeuf <jpoimboe@kernel.org>
Link: https://lore.kernel.org/20250418161721.1855190-6-david.kaplan@amd.com
parent 203d81f8

arch/x86/kernel/cpu/bugs.c

+0 −65
Original line number Diff line number Diff line
@@ -62,8 +62,6 @@ static void __init l1tf_select_mitigation(void); 
static void __init mds_select_mitigation(void);

static void __init mds_update_mitigation(void);

static void __init mds_apply_mitigation(void);

static void __init md_clear_update_mitigation(void);

static void __init md_clear_select_mitigation(void);

static void __init taa_select_mitigation(void);

static void __init taa_update_mitigation(void);

static void __init taa_apply_mitigation(void);
@@ -204,7 +202,6 @@ void __init cpu_select_mitigations(void) 
	taa_select_mitigation();

	mmio_select_mitigation();

	rfds_select_mitigation();

	md_clear_select_mitigation();

	srbds_select_mitigation();

	l1d_flush_select_mitigation();
@@ -691,68 +688,6 @@ static __init int rfds_parse_cmdline(char *str) 
}

early_param("reg_file_data_sampling", rfds_parse_cmdline);



#undef pr_fmt

#define pr_fmt(fmt)     "" fmt



static void __init md_clear_update_mitigation(void)

{

	if (cpu_mitigations_off())

		return;



	if (!boot_cpu_has(X86_FEATURE_CLEAR_CPU_BUF))

		goto out;



	/*

	 * X86_FEATURE_CLEAR_CPU_BUF is now enabled. Update MDS, TAA and MMIO

	 * Stale Data mitigation, if necessary.

	 */

	if (mds_mitigation == MDS_MITIGATION_OFF &&

	    boot_cpu_has_bug(X86_BUG_MDS)) {

		mds_mitigation = MDS_MITIGATION_FULL;

		mds_select_mitigation();

	}

	if (taa_mitigation == TAA_MITIGATION_OFF &&

	    boot_cpu_has_bug(X86_BUG_TAA)) {

		taa_mitigation = TAA_MITIGATION_VERW;

		taa_select_mitigation();

	}

	/*

	 * MMIO_MITIGATION_OFF is not checked here so that cpu_buf_vm_clear

	 * gets updated correctly as per X86_FEATURE_CLEAR_CPU_BUF state.

	 */

	if (boot_cpu_has_bug(X86_BUG_MMIO_STALE_DATA)) {

		mmio_mitigation = MMIO_MITIGATION_VERW;

		mmio_select_mitigation();

	}

	if (rfds_mitigation == RFDS_MITIGATION_OFF &&

	    boot_cpu_has_bug(X86_BUG_RFDS)) {

		rfds_mitigation = RFDS_MITIGATION_VERW;

		rfds_select_mitigation();

	}

out:

	if (boot_cpu_has_bug(X86_BUG_MDS))

		pr_info("MDS: %s\n", mds_strings[mds_mitigation]);

	if (boot_cpu_has_bug(X86_BUG_TAA))

		pr_info("TAA: %s\n", taa_strings[taa_mitigation]);

	if (boot_cpu_has_bug(X86_BUG_MMIO_STALE_DATA))

		pr_info("MMIO Stale Data: %s\n", mmio_strings[mmio_mitigation]);

	else if (boot_cpu_has_bug(X86_BUG_MMIO_UNKNOWN))

		pr_info("MMIO Stale Data: Unknown: No mitigations\n");

	if (boot_cpu_has_bug(X86_BUG_RFDS))

		pr_info("Register File Data Sampling: %s\n", rfds_strings[rfds_mitigation]);

}



static void __init md_clear_select_mitigation(void)

{



	/*

	 * As these mitigations are inter-related and rely on VERW instruction

	 * to clear the microarchitural buffers, update and print their status

	 * after mitigation selection is done for each of these vulnerabilities.

	 */

	md_clear_update_mitigation();

}



#undef pr_fmt

#define pr_fmt(fmt)	"SRBDS: " fmt