Commit 40be821d authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge tag 'x86-urgent-2020-11-08' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 

Pull x86 fixes from Thomas Gleixner:
 "A set of x86 fixes:

   - Use SYM_FUNC_START_WEAK in the mem* ASM functions instead of a
     combination of .weak and SYM_FUNC_START_LOCAL which makes LLVMs
     integrated assembler upset

   - Correct the mitigation selection logic which prevented the related
     prctl to work correctly

   - Make the UV5 hubless system work correctly by fixing up the
     malformed table entries and adding the missing ones"

* tag 'x86-urgent-2020-11-08' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/platform/uv: Recognize UV5 hubless system identifier
  x86/platform/uv: Remove spaces from OEM IDs
  x86/platform/uv: Fix missing OEM_TABLE_ID
  x86/speculation: Allow IBPB to be conditionally enabled on CPUs with always-on STIBP
  x86/lib: Change .weak to SYM_FUNC_START_WEAK for arch/x86/lib/mem*_64.S
parents 100e3891 801284f9

arch/x86/kernel/apic/x2apic_uv_x.c

+18 −5
Original line number Diff line number Diff line
@@ -290,6 +290,9 @@ static void __init uv_stringify(int len, char *to, char *from) 
{

	/* Relies on 'to' being NULL chars so result will be NULL terminated */

	strncpy(to, from, len-1);



	/* Trim trailing spaces */

	(void)strim(to);

}



/* Find UV arch type entry in UVsystab */
@@ -366,7 +369,7 @@ static int __init early_get_arch_type(void) 
	return ret;

}



static int __init uv_set_system_type(char *_oem_id)

static int __init uv_set_system_type(char *_oem_id, char *_oem_table_id)

{

	/* Save OEM_ID passed from ACPI MADT */

	uv_stringify(sizeof(oem_id), oem_id, _oem_id);
@@ -386,13 +389,23 @@ static int __init uv_set_system_type(char *_oem_id) 
			/* (Not hubless), not a UV */

			return 0;



		/* Is UV hubless system */

		uv_hubless_system = 0x01;



		/* UV5 Hubless */

		if (strncmp(uv_archtype, "NSGI5", 5) == 0)

			uv_hubless_system |= 0x20;



		/* UV4 Hubless: CH */

		if (strncmp(uv_archtype, "NSGI4", 5) == 0)

			uv_hubless_system = 0x11;

		else if (strncmp(uv_archtype, "NSGI4", 5) == 0)

			uv_hubless_system |= 0x10;



		/* UV3 Hubless: UV300/MC990X w/o hub */

		else

			uv_hubless_system = 0x9;

			uv_hubless_system |= 0x8;



		/* Copy APIC type */

		uv_stringify(sizeof(oem_table_id), oem_table_id, _oem_table_id);



		pr_info("UV: OEM IDs %s/%s, SystemType %d, HUBLESS ID %x\n",

			oem_id, oem_table_id, uv_system_type, uv_hubless_system);
@@ -456,7 +469,7 @@ static int __init uv_acpi_madt_oem_check(char *_oem_id, char *_oem_table_id) 
	uv_cpu_info->p_uv_hub_info = &uv_hub_info_node0;



	/* If not UV, return. */

	if (likely(uv_set_system_type(_oem_id) == 0))

	if (uv_set_system_type(_oem_id, _oem_table_id) == 0)

		return 0;



	/* Save and Decode OEM Table ID */

arch/x86/kernel/cpu/bugs.c

+33 −18
Original line number Diff line number Diff line
@@ -1254,6 +1254,14 @@ static int ssb_prctl_set(struct task_struct *task, unsigned long ctrl) 
	return 0;

}



static bool is_spec_ib_user_controlled(void)

{

	return spectre_v2_user_ibpb == SPECTRE_V2_USER_PRCTL ||

		spectre_v2_user_ibpb == SPECTRE_V2_USER_SECCOMP ||

		spectre_v2_user_stibp == SPECTRE_V2_USER_PRCTL ||

		spectre_v2_user_stibp == SPECTRE_V2_USER_SECCOMP;

}



static int ib_prctl_set(struct task_struct *task, unsigned long ctrl)

{

	switch (ctrl) {
@@ -1261,16 +1269,26 @@ static int ib_prctl_set(struct task_struct *task, unsigned long ctrl) 
		if (spectre_v2_user_ibpb == SPECTRE_V2_USER_NONE &&

		    spectre_v2_user_stibp == SPECTRE_V2_USER_NONE)

			return 0;



		/*

		 * Indirect branch speculation is always disabled in strict

		 * mode. It can neither be enabled if it was force-disabled

		 * by a  previous prctl call.

		 * With strict mode for both IBPB and STIBP, the instruction

		 * code paths avoid checking this task flag and instead,

		 * unconditionally run the instruction. However, STIBP and IBPB

		 * are independent and either can be set to conditionally

		 * enabled regardless of the mode of the other.

		 *

		 * If either is set to conditional, allow the task flag to be

		 * updated, unless it was force-disabled by a previous prctl

		 * call. Currently, this is possible on an AMD CPU which has the

		 * feature X86_FEATURE_AMD_STIBP_ALWAYS_ON. In this case, if the

		 * kernel is booted with 'spectre_v2_user=seccomp', then

		 * spectre_v2_user_ibpb == SPECTRE_V2_USER_SECCOMP and

		 * spectre_v2_user_stibp == SPECTRE_V2_USER_STRICT_PREFERRED.

		 */

		if (spectre_v2_user_ibpb == SPECTRE_V2_USER_STRICT ||

		    spectre_v2_user_stibp == SPECTRE_V2_USER_STRICT ||

		    spectre_v2_user_stibp == SPECTRE_V2_USER_STRICT_PREFERRED ||

		if (!is_spec_ib_user_controlled() ||

		    task_spec_ib_force_disable(task))

			return -EPERM;



		task_clear_spec_ib_disable(task);

		task_update_spec_tif(task);

		break;
@@ -1283,10 +1301,10 @@ static int ib_prctl_set(struct task_struct *task, unsigned long ctrl) 
		if (spectre_v2_user_ibpb == SPECTRE_V2_USER_NONE &&

		    spectre_v2_user_stibp == SPECTRE_V2_USER_NONE)

			return -EPERM;

		if (spectre_v2_user_ibpb == SPECTRE_V2_USER_STRICT ||

		    spectre_v2_user_stibp == SPECTRE_V2_USER_STRICT ||

		    spectre_v2_user_stibp == SPECTRE_V2_USER_STRICT_PREFERRED)



		if (!is_spec_ib_user_controlled())

			return 0;



		task_set_spec_ib_disable(task);

		if (ctrl == PR_SPEC_FORCE_DISABLE)

			task_set_spec_ib_force_disable(task);
@@ -1351,20 +1369,17 @@ static int ib_prctl_get(struct task_struct *task) 
	if (spectre_v2_user_ibpb == SPECTRE_V2_USER_NONE &&

	    spectre_v2_user_stibp == SPECTRE_V2_USER_NONE)

		return PR_SPEC_ENABLE;

	else if (spectre_v2_user_ibpb == SPECTRE_V2_USER_STRICT ||

	    spectre_v2_user_stibp == SPECTRE_V2_USER_STRICT ||

	    spectre_v2_user_stibp == SPECTRE_V2_USER_STRICT_PREFERRED)

		return PR_SPEC_DISABLE;

	else if (spectre_v2_user_ibpb == SPECTRE_V2_USER_PRCTL ||

	    spectre_v2_user_ibpb == SPECTRE_V2_USER_SECCOMP ||

	    spectre_v2_user_stibp == SPECTRE_V2_USER_PRCTL ||

	    spectre_v2_user_stibp == SPECTRE_V2_USER_SECCOMP) {

	else if (is_spec_ib_user_controlled()) {

		if (task_spec_ib_force_disable(task))

			return PR_SPEC_PRCTL | PR_SPEC_FORCE_DISABLE;

		if (task_spec_ib_disable(task))

			return PR_SPEC_PRCTL | PR_SPEC_DISABLE;

		return PR_SPEC_PRCTL | PR_SPEC_ENABLE;

	} else

	} else if (spectre_v2_user_ibpb == SPECTRE_V2_USER_STRICT ||

	    spectre_v2_user_stibp == SPECTRE_V2_USER_STRICT ||

	    spectre_v2_user_stibp == SPECTRE_V2_USER_STRICT_PREFERRED)

		return PR_SPEC_DISABLE;

	else

		return PR_SPEC_NOT_AFFECTED;

}

arch/x86/lib/memcpy_64.S

+1 −3
Original line number Diff line number Diff line
@@ -16,8 +16,6 @@ 
 * to a jmp to memcpy_erms which does the REP; MOVSB mem copy.

 */



.weak memcpy



/*

 * memcpy - Copy a memory block.

 *
@@ -30,7 +28,7 @@ 
 * rax original destination

 */

SYM_FUNC_START_ALIAS(__memcpy)

SYM_FUNC_START_LOCAL(memcpy)

SYM_FUNC_START_WEAK(memcpy)

	ALTERNATIVE_2 "jmp memcpy_orig", "", X86_FEATURE_REP_GOOD, \

		      "jmp memcpy_erms", X86_FEATURE_ERMS

arch/x86/lib/memmove_64.S

+1 −3
Original line number Diff line number Diff line
@@ -24,9 +24,7 @@ 
 * Output:

 * rax: dest

 */

.weak memmove



SYM_FUNC_START_ALIAS(memmove)

SYM_FUNC_START_WEAK(memmove)

SYM_FUNC_START(__memmove)



	mov %rdi, %rax

arch/x86/lib/memset_64.S

+1 −3
Original line number Diff line number Diff line
@@ -6,8 +6,6 @@ 
#include <asm/alternative-asm.h>

#include <asm/export.h>



.weak memset



/*

 * ISO C memset - set a memory block to a byte value. This function uses fast

 * string to get better performance than the original function. The code is
@@ -19,7 +17,7 @@ 
 *

 * rax   original destination

 */

SYM_FUNC_START_ALIAS(memset)

SYM_FUNC_START_WEAK(memset)

SYM_FUNC_START(__memset)

	/*

	 * Some CPUs support enhanced REP MOVSB/STOSB feature. It is recommended

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