Commit 1de564b8 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

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
parents 42b682a3 aeb84412

Documentation/process/maintainer-tip.rst

+14 −0
Original line number Diff line number Diff line
@@ -437,6 +437,20 @@ in a private repository which allows interested people to easily pull the 
series for testing. The usual way to offer this is a git URL in the cover

letter of the patch series.



Testing

^^^^^^^



Code should be tested before submitting to the tip maintainers.  Anything

other than minor changes should be built, booted and tested with

comprehensive (and heavyweight) kernel debugging options enabled.



These debugging options can be found in kernel/configs/x86_debug.config

and can be added to an existing kernel config by running:



	make x86_debug.config



Some of these options are x86-specific and can be left out when testing

on other architectures.



Coding style notes

------------------

arch/x86/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -313,5 +313,6 @@ define archhelp 
  echo  ''

  echo  '  kvm_guest.config	- Enable Kconfig items for running this kernel as a KVM guest'

  echo  '  xen.config		- Enable Kconfig items for running this kernel as a Xen guest'

  echo  '  x86_debug.config	- Enable tip tree debugging options for testing'



endef

arch/x86/boot/boot.h

+24 −12
Original line number Diff line number Diff line
@@ -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! */

arch/x86/boot/main.c

+1 −1
Original line number Diff line number Diff line
@@ -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));

kernel/configs/x86_debug.config

0 → 100644
+18 −0
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CONFIG_X86_DEBUG_FPU=y

CONFIG_LOCK_STAT=y

CONFIG_DEBUG_VM=y

CONFIG_DEBUG_VM_VMACACHE=y

CONFIG_DEBUG_VM_RB=y

CONFIG_DEBUG_SLAB=y

CONFIG_DEBUG_KMEMLEAK=y

CONFIG_DEBUG_PAGEALLOC=y

CONFIG_SLUB_DEBUG_ON=y

CONFIG_KMEMCHECK=y

CONFIG_DEBUG_OBJECTS=y

CONFIG_DEBUG_OBJECTS_ENABLE_DEFAULT=1

CONFIG_GCOV_KERNEL=y

CONFIG_LOCKDEP=y

CONFIG_PROVE_LOCKING=y

CONFIG_SCHEDSTATS=y

CONFIG_VMLINUX_VALIDATION=y

CONFIG_DEBUG_INFO_DWARF_TOOLCHAIN_DEFAULT=y