Commit a5e8131a authored by Christophe Leroy's avatar Christophe Leroy Committed by Andrew Morton
Browse files

arm64, powerpc, riscv, s390, x86: ptdump: refactor CONFIG_DEBUG_WX 

All architectures using the core ptdump functionality also implement
CONFIG_DEBUG_WX, and they all do it more or less the same way, with a
function called debug_checkwx() that is called by mark_rodata_ro(), which
is a substitute to ptdump_check_wx() when CONFIG_DEBUG_WX is set and a
no-op otherwise.

Refactor by centrally defining debug_checkwx() in linux/ptdump.h and call
debug_checkwx() immediately after calling mark_rodata_ro() instead of
calling it at the end of every mark_rodata_ro().

On x86_32, mark_rodata_ro() first checks __supported_pte_mask has _PAGE_NX
before calling debug_checkwx().  Now the check is inside the callee
ptdump_walk_pgd_level_checkwx().

On powerpc_64, mark_rodata_ro() bails out early before calling
ptdump_check_wx() when the MMU doesn't have KERNEL_RO feature.  The check
is now also done in ptdump_check_wx() as it is called outside
mark_rodata_ro().

Link: https://lkml.kernel.org/r/a59b102d7964261d31ead0316a9f18628e4e7a8e.1706610398.git.christophe.leroy@csgroup.eu


Signed-off-by: default avatarChristophe Leroy <christophe.leroy@csgroup.eu>
Reviewed-by: default avatarAlexandre Ghiti <alexghiti@rivosinc.com>
Cc: Albert Ou <aou@eecs.berkeley.edu>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: "Aneesh Kumar K.V (IBM)" <aneesh.kumar@kernel.org>
Cc: Borislav Petkov (AMD) <bp@alien8.de>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christian Borntraeger <borntraeger@linux.ibm.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com>
Cc: Greg KH <greg@kroah.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: "Naveen N. Rao" <naveen.n.rao@linux.ibm.com>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Phong Tran <tranmanphong@gmail.com>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Steven Price <steven.price@arm.com>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
parent a90f0a02

arch/arm64/include/asm/ptdump.h

+0 −7
Original line number Diff line number Diff line
@@ -29,13 +29,6 @@ void __init ptdump_debugfs_register(struct ptdump_info *info, const char *name); 
static inline void ptdump_debugfs_register(struct ptdump_info *info,

					   const char *name) { }

#endif

void ptdump_check_wx(void);

#endif /* CONFIG_PTDUMP_CORE */



#ifdef CONFIG_DEBUG_WX

#define debug_checkwx()	ptdump_check_wx()

#else

#define debug_checkwx()	do { } while (0)

#endif



#endif /* __ASM_PTDUMP_H */

arch/arm64/mm/mmu.c

+0 −2
Original line number Diff line number Diff line
@@ -632,8 +632,6 @@ void mark_rodata_ro(void) 
	section_size = (unsigned long)__init_begin - (unsigned long)__start_rodata;

	update_mapping_prot(__pa_symbol(__start_rodata), (unsigned long)__start_rodata,

			    section_size, PAGE_KERNEL_RO);



	debug_checkwx();

}



static void __init map_kernel_segment(pgd_t *pgdp, void *va_start, void *va_end,

arch/powerpc/mm/mmu_decl.h

+0 −6
Original line number Diff line number Diff line
@@ -171,12 +171,6 @@ static inline void mmu_mark_rodata_ro(void) { } 
void __init mmu_mapin_immr(void);

#endif



#ifdef CONFIG_DEBUG_WX

void ptdump_check_wx(void);

#else

static inline void ptdump_check_wx(void) { }

#endif



static inline bool debug_pagealloc_enabled_or_kfence(void)

{

	return IS_ENABLED(CONFIG_KFENCE) || debug_pagealloc_enabled();

arch/powerpc/mm/pgtable_32.c

+0 −4
Original line number Diff line number Diff line
@@ -153,7 +153,6 @@ void mark_rodata_ro(void) 


	if (v_block_mapped((unsigned long)_stext + 1)) {

		mmu_mark_rodata_ro();

		ptdump_check_wx();

		return;

	}
@@ -166,9 +165,6 @@ void mark_rodata_ro(void) 
		   PFN_DOWN((unsigned long)_stext);



	set_memory_ro((unsigned long)_stext, numpages);



	// mark_initmem_nx() should have already run by now

	ptdump_check_wx();

}

#endif

arch/powerpc/mm/pgtable_64.c

+0 −3
Original line number Diff line number Diff line
@@ -150,9 +150,6 @@ void mark_rodata_ro(void) 
		radix__mark_rodata_ro();

	else

		hash__mark_rodata_ro();



	// mark_initmem_nx() should have already run by now

	ptdump_check_wx();

}



void mark_initmem_nx(void)