Commit f66d6acc authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge tag 'x86_urgent_for_v6.12' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 

Pull x86 fixes from Borislav Petkov:

 - Make sure a kdump kernel with CONFIG_IMA_KEXEC enabled and booted on
   an AMD SME enabled hardware properly decrypts the ima_kexec buffer
   information passed to it from the previous kernel

 - Fix building the kernel with Clang where a non-TLS definition of the
   stack protector guard cookie leads to bogus code generation

 - Clear a wrongly advertised virtualized VMLOAD/VMSAVE feature flag on
   some Zen4 client systems as those insns are not supported on client

* tag 'x86_urgent_for_v6.12' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/mm: Fix a kdump kernel failure on SME system when CONFIG_IMA_KEXEC=y
  x86/stackprotector: Work around strict Clang TLS symbol requirements
  x86/CPU/AMD: Clear virtualized VMLOAD/VMSAVE on Zen4 client
parents 4a5df379 8d9ffb2f

arch/x86/Makefile

+3 −2
Original line number Diff line number Diff line
@@ -142,7 +142,8 @@ ifeq ($(CONFIG_X86_32),y) 


    ifeq ($(CONFIG_STACKPROTECTOR),y)

        ifeq ($(CONFIG_SMP),y)

			KBUILD_CFLAGS += -mstack-protector-guard-reg=fs -mstack-protector-guard-symbol=__stack_chk_guard

            KBUILD_CFLAGS += -mstack-protector-guard-reg=fs \

                             -mstack-protector-guard-symbol=__ref_stack_chk_guard

        else

            KBUILD_CFLAGS += -mstack-protector-guard=global

        endif

arch/x86/entry/entry.S

+16 −0
Original line number Diff line number Diff line
@@ -51,3 +51,19 @@ EXPORT_SYMBOL_GPL(mds_verw_sel); 
.popsection



THUNK warn_thunk_thunk, __warn_thunk



#ifndef CONFIG_X86_64

/*

 * Clang's implementation of TLS stack cookies requires the variable in

 * question to be a TLS variable. If the variable happens to be defined as an

 * ordinary variable with external linkage in the same compilation unit (which

 * amounts to the whole of vmlinux with LTO enabled), Clang will drop the

 * segment register prefix from the references, resulting in broken code. Work

 * around this by avoiding the symbol used in -mstack-protector-guard-symbol=

 * entirely in the C code, and use an alias emitted by the linker script

 * instead.

 */

#ifdef CONFIG_STACKPROTECTOR

EXPORT_SYMBOL(__ref_stack_chk_guard);

#endif

#endif

arch/x86/include/asm/asm-prototypes.h

+3 −0
Original line number Diff line number Diff line
@@ -20,3 +20,6 @@ 
extern void cmpxchg8b_emu(void);

#endif



#if defined(__GENKSYMS__) && defined(CONFIG_STACKPROTECTOR)

extern unsigned long __ref_stack_chk_guard;

#endif

arch/x86/kernel/cpu/amd.c

+11 −0
Original line number Diff line number Diff line
@@ -924,6 +924,17 @@ static void init_amd_zen4(struct cpuinfo_x86 *c) 
{

	if (!cpu_has(c, X86_FEATURE_HYPERVISOR))

		msr_set_bit(MSR_ZEN4_BP_CFG, MSR_ZEN4_BP_CFG_SHARED_BTB_FIX_BIT);



	/*

	 * These Zen4 SoCs advertise support for virtualized VMLOAD/VMSAVE

	 * in some BIOS versions but they can lead to random host reboots.

	 */

	switch (c->x86_model) {

	case 0x18 ... 0x1f:

	case 0x60 ... 0x7f:

		clear_cpu_cap(c, X86_FEATURE_V_VMSAVE_VMLOAD);

		break;

	}

}



static void init_amd_zen5(struct cpuinfo_x86 *c)

arch/x86/kernel/cpu/common.c

+2 −0
Original line number Diff line number Diff line
@@ -2089,8 +2089,10 @@ void syscall_init(void) 


#ifdef CONFIG_STACKPROTECTOR

DEFINE_PER_CPU(unsigned long, __stack_chk_guard);

#ifndef CONFIG_SMP

EXPORT_PER_CPU_SYMBOL(__stack_chk_guard);

#endif

#endif



#endif	/* CONFIG_X86_64 */