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authorLinus Torvalds <torvalds@linux-foundation.org>2020-10-24 11:49:32 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2020-10-24 11:49:32 -0700
commitc51ae1247262d4b19451ded1107d9b1b69c57541 (patch)
treebdb5dbdb2f0579b64d4d97677b9bdeaa52d60d03
parentb6f96e75ae121ead54da3f58c545d68184079f90 (diff)
parentb17a45b6e53f6613118b2e5cfc4a992cc50deb2c (diff)
Merge tag 'x86_seves_fixes_for_v5.10_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 SEV-ES fixes from Borislav Petkov: "Three fixes to SEV-ES to correct setting up the new early pagetable on 5-level paging machines, to always map boot_params and the kernel cmdline, and disable stack protector for ../compressed/head{32,64}.c. (Arvind Sankar)" * tag 'x86_seves_fixes_for_v5.10_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/boot/64: Explicitly map boot_params and command line x86/head/64: Disable stack protection for head$(BITS).o x86/boot/64: Initialize 5-level paging variables earlier
-rw-r--r--arch/x86/boot/compressed/head_64.S3
-rw-r--r--arch/x86/boot/compressed/ident_map_64.c27
-rw-r--r--arch/x86/boot/compressed/kaslr.c8
-rw-r--r--arch/x86/boot/compressed/pgtable_64.c16
-rw-r--r--arch/x86/kernel/Makefile2
5 files changed, 40 insertions, 16 deletions
diff --git a/arch/x86/boot/compressed/head_64.S b/arch/x86/boot/compressed/head_64.S
index 1c80f1738fd9..017de6cc87dc 100644
--- a/arch/x86/boot/compressed/head_64.S
+++ b/arch/x86/boot/compressed/head_64.S
@@ -544,6 +544,9 @@ SYM_FUNC_START_LOCAL_NOALIGN(.Lrelocated)
pushq %rsi
call set_sev_encryption_mask
call load_stage2_idt
+
+ /* Pass boot_params to initialize_identity_maps() */
+ movq (%rsp), %rdi
call initialize_identity_maps
popq %rsi
diff --git a/arch/x86/boot/compressed/ident_map_64.c b/arch/x86/boot/compressed/ident_map_64.c
index 063a60edcf99..a5e5db6ada3c 100644
--- a/arch/x86/boot/compressed/ident_map_64.c
+++ b/arch/x86/boot/compressed/ident_map_64.c
@@ -33,11 +33,11 @@
#define __PAGE_OFFSET __PAGE_OFFSET_BASE
#include "../../mm/ident_map.c"
-#ifdef CONFIG_X86_5LEVEL
-unsigned int __pgtable_l5_enabled;
-unsigned int pgdir_shift = 39;
-unsigned int ptrs_per_p4d = 1;
-#endif
+#define _SETUP
+#include <asm/setup.h> /* For COMMAND_LINE_SIZE */
+#undef _SETUP
+
+extern unsigned long get_cmd_line_ptr(void);
/* Used by PAGE_KERN* macros: */
pteval_t __default_kernel_pte_mask __read_mostly = ~0;
@@ -107,8 +107,10 @@ static void add_identity_map(unsigned long start, unsigned long end)
}
/* Locates and clears a region for a new top level page table. */
-void initialize_identity_maps(void)
+void initialize_identity_maps(void *rmode)
{
+ unsigned long cmdline;
+
/* Exclude the encryption mask from __PHYSICAL_MASK */
physical_mask &= ~sme_me_mask;
@@ -149,10 +151,19 @@ void initialize_identity_maps(void)
}
/*
- * New page-table is set up - map the kernel image and load it
- * into cr3.
+ * New page-table is set up - map the kernel image, boot_params and the
+ * command line. The uncompressed kernel requires boot_params and the
+ * command line to be mapped in the identity mapping. Map them
+ * explicitly here in case the compressed kernel does not touch them,
+ * or does not touch all the pages covering them.
*/
add_identity_map((unsigned long)_head, (unsigned long)_end);
+ boot_params = rmode;
+ add_identity_map((unsigned long)boot_params, (unsigned long)(boot_params + 1));
+ cmdline = get_cmd_line_ptr();
+ add_identity_map(cmdline, cmdline + COMMAND_LINE_SIZE);
+
+ /* Load the new page-table. */
write_cr3(top_level_pgt);
}
diff --git a/arch/x86/boot/compressed/kaslr.c b/arch/x86/boot/compressed/kaslr.c
index b59547ce5b19..b92fffbe761f 100644
--- a/arch/x86/boot/compressed/kaslr.c
+++ b/arch/x86/boot/compressed/kaslr.c
@@ -840,14 +840,6 @@ void choose_random_location(unsigned long input,
return;
}
-#ifdef CONFIG_X86_5LEVEL
- if (__read_cr4() & X86_CR4_LA57) {
- __pgtable_l5_enabled = 1;
- pgdir_shift = 48;
- ptrs_per_p4d = 512;
- }
-#endif
-
boot_params->hdr.loadflags |= KASLR_FLAG;
if (IS_ENABLED(CONFIG_X86_32))
diff --git a/arch/x86/boot/compressed/pgtable_64.c b/arch/x86/boot/compressed/pgtable_64.c
index 7d0394f4ebf9..5def1674d6f1 100644
--- a/arch/x86/boot/compressed/pgtable_64.c
+++ b/arch/x86/boot/compressed/pgtable_64.c
@@ -8,6 +8,13 @@
#define BIOS_START_MIN 0x20000U /* 128K, less than this is insane */
#define BIOS_START_MAX 0x9f000U /* 640K, absolute maximum */
+#ifdef CONFIG_X86_5LEVEL
+/* __pgtable_l5_enabled needs to be in .data to avoid being cleared along with .bss */
+unsigned int __section(.data) __pgtable_l5_enabled;
+unsigned int __section(.data) pgdir_shift = 39;
+unsigned int __section(.data) ptrs_per_p4d = 1;
+#endif
+
struct paging_config {
unsigned long trampoline_start;
unsigned long l5_required;
@@ -198,4 +205,13 @@ void cleanup_trampoline(void *pgtable)
/* Restore trampoline memory */
memcpy(trampoline_32bit, trampoline_save, TRAMPOLINE_32BIT_SIZE);
+
+ /* Initialize variables for 5-level paging */
+#ifdef CONFIG_X86_5LEVEL
+ if (__read_cr4() & X86_CR4_LA57) {
+ __pgtable_l5_enabled = 1;
+ pgdir_shift = 48;
+ ptrs_per_p4d = 512;
+ }
+#endif
}
diff --git a/arch/x86/kernel/Makefile b/arch/x86/kernel/Makefile
index 04ceea8f4a89..68608bd892c0 100644
--- a/arch/x86/kernel/Makefile
+++ b/arch/x86/kernel/Makefile
@@ -47,6 +47,8 @@ endif
# non-deterministic coverage.
KCOV_INSTRUMENT := n
+CFLAGS_head$(BITS).o += -fno-stack-protector
+
CFLAGS_irq.o := -I $(srctree)/$(src)/../include/asm/trace
obj-y := process_$(BITS).o signal.o

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