Commit da364fc5 authored by Ingo Molnar's avatar Ingo Molnar
Browse files

x86/alternatives: Rename 'poking_addr' to 'text_poke_mm_addr' 



Put it into the text_poke_* namespace of <asm/text-patching.h>.

Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
Cc: Juergen Gross <jgross@suse.com>
Cc: "H . Peter Anvin" <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/r/20250411054105.2341982-10-mingo@kernel.org
parent a5c832e0

arch/x86/include/asm/text-patching.h

+1 −1
Original line number Diff line number Diff line
@@ -129,7 +129,7 @@ void *text_gen_insn(u8 opcode, const void *addr, const void *dest) 


extern int after_bootmem;

extern __ro_after_init struct mm_struct *text_poke_mm;

extern __ro_after_init unsigned long poking_addr;

extern __ro_after_init unsigned long text_poke_mm_addr;



#ifndef CONFIG_UML_X86

static __always_inline

arch/x86/kernel/alternative.c

+8 −8
Original line number Diff line number Diff line
@@ -2192,7 +2192,7 @@ static inline temp_mm_state_t use_temporary_mm(struct mm_struct *mm) 
}



__ro_after_init struct mm_struct *text_poke_mm;

__ro_after_init unsigned long poking_addr;

__ro_after_init unsigned long text_poke_mm_addr;



static inline void unuse_temporary_mm(temp_mm_state_t prev_state)

{
@@ -2266,7 +2266,7 @@ static void *__text_poke(text_poke_f func, void *addr, const void *src, size_t l 
	/*

	 * The lock is not really needed, but this allows to avoid open-coding.

	 */

	ptep = get_locked_pte(text_poke_mm, poking_addr, &ptl);

	ptep = get_locked_pte(text_poke_mm, text_poke_mm_addr, &ptl);



	/*

	 * This must not fail; preallocated in poking_init().
@@ -2276,11 +2276,11 @@ static void *__text_poke(text_poke_f func, void *addr, const void *src, size_t l 
	local_irq_save(flags);



	pte = mk_pte(pages[0], pgprot);

	set_pte_at(text_poke_mm, poking_addr, ptep, pte);

	set_pte_at(text_poke_mm, text_poke_mm_addr, ptep, pte);



	if (cross_page_boundary) {

		pte = mk_pte(pages[1], pgprot);

		set_pte_at(text_poke_mm, poking_addr + PAGE_SIZE, ptep + 1, pte);

		set_pte_at(text_poke_mm, text_poke_mm_addr + PAGE_SIZE, ptep + 1, pte);

	}



	/*
@@ -2290,7 +2290,7 @@ static void *__text_poke(text_poke_f func, void *addr, const void *src, size_t l 
	prev = use_temporary_mm(text_poke_mm);



	kasan_disable_current();

	func((u8 *)poking_addr + offset_in_page(addr), src, len);

	func((u8 *)text_poke_mm_addr + offset_in_page(addr), src, len);

	kasan_enable_current();



	/*
@@ -2299,9 +2299,9 @@ static void *__text_poke(text_poke_f func, void *addr, const void *src, size_t l 
	 */

	barrier();



	pte_clear(text_poke_mm, poking_addr, ptep);

	pte_clear(text_poke_mm, text_poke_mm_addr, ptep);

	if (cross_page_boundary)

		pte_clear(text_poke_mm, poking_addr + PAGE_SIZE, ptep + 1);

		pte_clear(text_poke_mm, text_poke_mm_addr + PAGE_SIZE, ptep + 1);



	/*

	 * Loading the previous page-table hierarchy requires a serializing
@@ -2314,7 +2314,7 @@ static void *__text_poke(text_poke_f func, void *addr, const void *src, size_t l 
	 * Flushing the TLB might involve IPIs, which would require enabled

	 * IRQs, but not if the mm is not used, as it is in this point.

	 */

	flush_tlb_mm_range(text_poke_mm, poking_addr, poking_addr +

	flush_tlb_mm_range(text_poke_mm, text_poke_mm_addr, text_poke_mm_addr +

			   (cross_page_boundary ? 2 : 1) * PAGE_SIZE,

			   PAGE_SHIFT, false);

arch/x86/mm/init.c

+5 −5
Original line number Diff line number Diff line
@@ -835,20 +835,20 @@ void __init poking_init(void) 
	 * will be mapped at the same PMD. We need 2 pages, so find space for 3,

	 * and adjust the address if the PMD ends after the first one.

	 */

	poking_addr = TASK_UNMAPPED_BASE;

	text_poke_mm_addr = TASK_UNMAPPED_BASE;

	if (IS_ENABLED(CONFIG_RANDOMIZE_BASE))

		poking_addr += (kaslr_get_random_long("Poking") & PAGE_MASK) %

		text_poke_mm_addr += (kaslr_get_random_long("Poking") & PAGE_MASK) %

			(TASK_SIZE - TASK_UNMAPPED_BASE - 3 * PAGE_SIZE);



	if (((poking_addr + PAGE_SIZE) & ~PMD_MASK) == 0)

		poking_addr += PAGE_SIZE;

	if (((text_poke_mm_addr + PAGE_SIZE) & ~PMD_MASK) == 0)

		text_poke_mm_addr += PAGE_SIZE;



	/*

	 * We need to trigger the allocation of the page-tables that will be

	 * needed for poking now. Later, poking may be performed in an atomic

	 * section, which might cause allocation to fail.

	 */

	ptep = get_locked_pte(text_poke_mm, poking_addr, &ptl);

	ptep = get_locked_pte(text_poke_mm, text_poke_mm_addr, &ptl);

	BUG_ON(!ptep);

	pte_unmap_unlock(ptep, ptl);

}