Merge tag 'x86-boot-2020-06-01' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull x86 boot updates from Ingo Molnar:
 "Misc updates:

   - Add the initrdmem= boot option to specify an initrd embedded in RAM
     (flash most likely)

   - Sanitize the CS value earlier during boot, which also fixes SEV-ES

   - Various fixes and smaller cleanups"

* tag 'x86-boot-2020-06-01' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/boot: Correct relocation destination on old linkers
  x86/boot/compressed/64: Switch to __KERNEL_CS after GDT is loaded
  x86/boot: Fix -Wint-to-pointer-cast build warning
  x86/boot: Add kstrtoul() from lib/
  x86/tboot: Mark tboot static
  x86/setup: Add an initrdmem= option to specify initrd physical address

3 files changed, 15 insertions, 6 deletions

diff --git a/arch/x86/boot/compressed/acpi.c b/arch/x86/boot/compressed/acpi.c
index ef2ad7253cd5..8bcbcee54aa1 100644
--- a/arch/x86/boot/compressed/acpi.c
+++ b/arch/x86/boot/compressed/acpi.c
@@ -280,9 +280,9 @@ acpi_physical_address get_rsdp_addr(void)
  */
 #define MAX_ADDR_LEN 19
 
-static acpi_physical_address get_cmdline_acpi_rsdp(void)
+static unsigned long get_cmdline_acpi_rsdp(void)
 {
-	acpi_physical_address addr = 0;
+	unsigned long addr = 0;
 
 #ifdef CONFIG_KEXEC
 	char val[MAX_ADDR_LEN] = { };
@@ -292,7 +292,7 @@ static acpi_physical_address get_cmdline_acpi_rsdp(void)
 	if (ret < 0)
 		return 0;
 
-	if (kstrtoull(val, 16, &addr))
+	if (boot_kstrtoul(val, 16, &addr))
 		return 0;
 #endif
 	return addr;
@@ -314,7 +314,6 @@ static unsigned long get_acpi_srat_table(void)
 	 * different ideas about whether to trust a command-line parameter.
 	 */
 	rsdp = (struct acpi_table_rsdp *)get_cmdline_acpi_rsdp();
-
 	if (!rsdp)
 		rsdp = (struct acpi_table_rsdp *)(long)
 			boot_params->acpi_rsdp_addr;
diff --git a/arch/x86/boot/compressed/head_32.S b/arch/x86/boot/compressed/head_32.S
index ab3307036ba4..03557f2174bf 100644
--- a/arch/x86/boot/compressed/head_32.S
+++ b/arch/x86/boot/compressed/head_32.S
@@ -49,16 +49,17 @@
  * Position Independent Executable (PIE) so that linker won't optimize
  * R_386_GOT32X relocation to its fixed symbol address.  Older
  * linkers generate R_386_32 relocations against locally defined symbols,
- * _bss, _ebss, _got and _egot, in PIE.  It isn't wrong, just less
+ * _bss, _ebss, _got, _egot and _end, in PIE.  It isn't wrong, just less
  * optimal than R_386_RELATIVE.  But the x86 kernel fails to properly handle
  * R_386_32 relocations when relocating the kernel.  To generate
- * R_386_RELATIVE relocations, we mark _bss, _ebss, _got and _egot as
+ * R_386_RELATIVE relocations, we mark _bss, _ebss, _got, _egot and _end as
  * hidden:
  */
 	.hidden _bss
 	.hidden _ebss
 	.hidden _got
 	.hidden _egot
+	.hidden _end
 
 	__HEAD
 SYM_FUNC_START(startup_32)
diff --git a/arch/x86/boot/compressed/head_64.S b/arch/x86/boot/compressed/head_64.S
index 4f7e6b84be07..e821a7d7d5c4 100644
--- a/arch/x86/boot/compressed/head_64.S
+++ b/arch/x86/boot/compressed/head_64.S
@@ -42,6 +42,7 @@
 	.hidden _ebss
 	.hidden _got
 	.hidden _egot
+	.hidden _end
 
 	__HEAD
 	.code32
@@ -393,6 +394,14 @@ SYM_CODE_START(startup_64)
 	addq	%rax, 2(%rax)
 	lgdt	(%rax)
 
+	/* Reload CS so IRET returns to a CS actually in the GDT */
+	pushq	$__KERNEL_CS
+	leaq	.Lon_kernel_cs(%rip), %rax
+	pushq	%rax
+	lretq
+
+.Lon_kernel_cs:
+
 	/*
 	 * paging_prepare() sets up the trampoline and checks if we need to
 	 * enable 5-level paging.