Commit dfca37d3 authored by Vasily Gorbik's avatar Vasily Gorbik Committed by Heiko Carstens
Browse files

s390/kasan: update kasan memory layout note 



Kasan shadow memory area has been moved to the end of kernel address
space since commit 9a39abb7 ("s390/boot: simplify and fix kernel
memory layout setup"). Change kasan memory layout note accordingly.

Reviewed-by: default avatarAlexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: default avatarVasily Gorbik <gor@linux.ibm.com>
Signed-off-by: default avatarHeiko Carstens <hca@linux.ibm.com>
parent 3400c35a

arch/s390/mm/kasan_init.c

+26 −30
Original line number Diff line number Diff line
@@ -272,37 +272,33 @@ void __init kasan_early_init(void) 
	/*

	 * Current memory layout:

	 * +- 0 -------------+	       +- shadow start -+

	 * | 1:1 ram mapping |	  /| 1/8 ram	    |

	 * |1:1 ident mapping|	      /|1/8 of ident map|

	 * |		     |	     / |		|

	 * +- end of ram ----+	/  +----------------+

	 * | ... gap ...     | /   |		    |

	 * |		     |/    |	kasan	    |

	 * +- shadow start --+	   |	zero	    |

	 * | 1/8 addr space  |	   |	page	    |

	 * +- shadow end    -+	   |	mapping	    |

	 * | ... gap ...     |\    |  (untracked)   |

	 * +- vmalloc area  -+ \   |		    |

	 * | vmalloc_size    |	\  |		    |

	 * +- modules vaddr -+	 \ +----------------+

	 * | 2Gb	     |	  \|	  unmapped  | allocated per module

	 * +-----------------+	   +- shadow end ---+

	 * +-end of ident map+	    /  +----------------+

	 * | ... gap ...     |	   /   |    kasan	|

	 * |		     |	  /    |  zero page	|

	 * +- vmalloc area  -+	 /     |   mapping	|

	 * | vmalloc_size    |	/      | (untracked)	|

	 * +- modules vaddr -+ /       +----------------+

	 * | 2Gb	     |/        |    unmapped	| allocated per module

	 * +- shadow start  -+	       +----------------+

	 * | 1/8 addr space  |	       | zero pg mapping| (untracked)

	 * +- shadow end ----+---------+- shadow end ---+

	 *

	 * Current memory layout (KASAN_VMALLOC):

	 * +- 0 -------------+	       +- shadow start -+

	 * | 1:1 ram mapping |	  /| 1/8 ram	    |

	 * |1:1 ident mapping|	      /|1/8 of ident map|

	 * |		     |	     / |		|

	 * +- end of ram ----+	/  +----------------+

	 * | ... gap ...     | /   |	kasan	    |

	 * |		     |/    |	zero	    |

	 * +- shadow start --+	   |	page	    |

	 * | 1/8 addr space  |	   |	mapping     |

	 * +- shadow end    -+	   |  (untracked)   |

	 * | ... gap ...     |\    |		    |

	 * +- vmalloc area  -+ \   +- vmalloc area -+

	 * | vmalloc_size    |	\  |shallow populate|

	 * +- modules vaddr -+	 \ +- modules area -+

	 * | 2Gb	     |	  \|shallow populate|

	 * +-----------------+	   +- shadow end ---+

	 * +-end of ident map+	    /  +----------------+

	 * | ... gap ...     |	   /   | kasan zero page| (untracked)

	 * |		     |	  /    | mapping	|

	 * +- vmalloc area  -+	 /     +----------------+

	 * | vmalloc_size    |	/      |shallow populate|

	 * +- modules vaddr -+ /       +----------------+

	 * | 2Gb	     |/        |shallow populate|

	 * +- shadow start  -+	       +----------------+

	 * | 1/8 addr space  |	       | zero pg mapping| (untracked)

	 * +- shadow end ----+---------+- shadow end ---+

	 */

	/* populate kasan shadow (for identity mapping and zero page mapping) */

	kasan_early_pgtable_populate(__sha(0), __sha(memsize), POPULATE_MAP);