Merge tag 'x86_build_for_v5.19_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull x86 build updates from Borislav Petkov:

 - Add a "make x86_debug.config" target which enables a bunch of useful
   config debug options when trying to debug an issue

 - A gcc-12 build warnings fix

* tag 'x86_build_for_v5.19_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/boot: Wrap literal addresses in absolute_pointer()
  x86/configs: Add x86 debugging Kconfig fragment plus docs

2 files changed, 25 insertions, 13 deletions

diff --git a/arch/x86/boot/boot.h b/arch/x86/boot/boot.h
index b42b91606ca8..148ba5c5106e 100644
--- a/arch/x86/boot/boot.h
+++ b/arch/x86/boot/boot.h
@@ -77,66 +77,78 @@ typedef unsigned int addr_t;
 
 static inline u8 rdfs8(addr_t addr)
 {
+	u8 *ptr = (u8 *)absolute_pointer(addr);
 	u8 v;
-	asm volatile("movb %%fs:%1,%0" : "=q" (v) : "m" (*(u8 *)addr));
+	asm volatile("movb %%fs:%1,%0" : "=q" (v) : "m" (*ptr));
 	return v;
 }
 static inline u16 rdfs16(addr_t addr)
 {
+	u16 *ptr = (u16 *)absolute_pointer(addr);
 	u16 v;
-	asm volatile("movw %%fs:%1,%0" : "=r" (v) : "m" (*(u16 *)addr));
+	asm volatile("movw %%fs:%1,%0" : "=r" (v) : "m" (*ptr));
 	return v;
 }
 static inline u32 rdfs32(addr_t addr)
 {
+	u32 *ptr = (u32 *)absolute_pointer(addr);
 	u32 v;
-	asm volatile("movl %%fs:%1,%0" : "=r" (v) : "m" (*(u32 *)addr));
+	asm volatile("movl %%fs:%1,%0" : "=r" (v) : "m" (*ptr));
 	return v;
 }
 
 static inline void wrfs8(u8 v, addr_t addr)
 {
-	asm volatile("movb %1,%%fs:%0" : "+m" (*(u8 *)addr) : "qi" (v));
+	u8 *ptr = (u8 *)absolute_pointer(addr);
+	asm volatile("movb %1,%%fs:%0" : "+m" (*ptr) : "qi" (v));
 }
 static inline void wrfs16(u16 v, addr_t addr)
 {
-	asm volatile("movw %1,%%fs:%0" : "+m" (*(u16 *)addr) : "ri" (v));
+	u16 *ptr = (u16 *)absolute_pointer(addr);
+	asm volatile("movw %1,%%fs:%0" : "+m" (*ptr) : "ri" (v));
 }
 static inline void wrfs32(u32 v, addr_t addr)
 {
-	asm volatile("movl %1,%%fs:%0" : "+m" (*(u32 *)addr) : "ri" (v));
+	u32 *ptr = (u32 *)absolute_pointer(addr);
+	asm volatile("movl %1,%%fs:%0" : "+m" (*ptr) : "ri" (v));
 }
 
 static inline u8 rdgs8(addr_t addr)
 {
+	u8 *ptr = (u8 *)absolute_pointer(addr);
 	u8 v;
-	asm volatile("movb %%gs:%1,%0" : "=q" (v) : "m" (*(u8 *)addr));
+	asm volatile("movb %%gs:%1,%0" : "=q" (v) : "m" (*ptr));
 	return v;
 }
 static inline u16 rdgs16(addr_t addr)
 {
+	u16 *ptr = (u16 *)absolute_pointer(addr);
 	u16 v;
-	asm volatile("movw %%gs:%1,%0" : "=r" (v) : "m" (*(u16 *)addr));
+	asm volatile("movw %%gs:%1,%0" : "=r" (v) : "m" (*ptr));
 	return v;
 }
 static inline u32 rdgs32(addr_t addr)
 {
+	u32 *ptr = (u32 *)absolute_pointer(addr);
 	u32 v;
-	asm volatile("movl %%gs:%1,%0" : "=r" (v) : "m" (*(u32 *)addr));
+	asm volatile("movl %%gs:%1,%0" : "=r" (v) : "m" (*ptr));
 	return v;
 }
 
 static inline void wrgs8(u8 v, addr_t addr)
 {
-	asm volatile("movb %1,%%gs:%0" : "+m" (*(u8 *)addr) : "qi" (v));
+	u8 *ptr = (u8 *)absolute_pointer(addr);
+	asm volatile("movb %1,%%gs:%0" : "+m" (*ptr) : "qi" (v));
 }
 static inline void wrgs16(u16 v, addr_t addr)
 {
-	asm volatile("movw %1,%%gs:%0" : "+m" (*(u16 *)addr) : "ri" (v));
+	u16 *ptr = (u16 *)absolute_pointer(addr);
+	asm volatile("movw %1,%%gs:%0" : "+m" (*ptr) : "ri" (v));
 }
 static inline void wrgs32(u32 v, addr_t addr)
 {
-	asm volatile("movl %1,%%gs:%0" : "+m" (*(u32 *)addr) : "ri" (v));
+	u32 *ptr = (u32 *)absolute_pointer(addr);
+	asm volatile("movl %1,%%gs:%0" : "+m" (*ptr) : "ri" (v));
 }
 
 /* Note: these only return true/false, not a signed return value! */
diff --git a/arch/x86/boot/main.c b/arch/x86/boot/main.c
index 1202d4f8a390..c4ea5258ab55 100644
--- a/arch/x86/boot/main.c
+++ b/arch/x86/boot/main.c
@@ -35,7 +35,7 @@ static void copy_boot_params(void)
 		u16 cl_offset;
 	};
 	const struct old_cmdline * const oldcmd =
-		(const struct old_cmdline *)OLD_CL_ADDRESS;
+		absolute_pointer(OLD_CL_ADDRESS);
 
 	BUILD_BUG_ON(sizeof(boot_params) != 4096);
 	memcpy(&boot_params.hdr, &hdr, sizeof(hdr));