From 117a913e7b1c380bb99796588b266547de959de9 Mon Sep 17 00:00:00 2001 From: Lv Ying Date: Thu, 23 Feb 2023 22:15:06 +0800 Subject: [PATCH 3/3] elf/ld.so: remove _mmap_hole when ld.so mmap PT_LOAD segment try to use hugepage When ld.so mmap PT_LOAD segment try to use hugepage, it's unnecessary to remap hole area, becasue __mmap_reserved_area already mmap reserved area as PROT_NONE. Besides _mmap_hole may mmap hole area from 4KB page misaligned addresses which will cause mmap faiure(invalid argument). Signed-off-by: Lv Ying --- elf/dl-load.h | 2 -- elf/dl-map-segments-hugepage.h | 26 -------------------------- 2 files changed, 28 deletions(-) diff --git a/elf/dl-load.h b/elf/dl-load.h index fcf91a47..f2428165 100644 --- a/elf/dl-load.h +++ b/elf/dl-load.h @@ -136,8 +136,6 @@ static const char *_dl_map_segments (struct link_map *l, int fd, N_("cannot map Non shared object file in hugepage") #define DL_MAP_SEGMENTS_ERROR_ARRANGE \ N_("shared object's PT_LOAD segment in wrong arrange") -#define DL_MAP_SEGMENTS_ERROR_MAP_HOLE_FILL \ - N_("failed to mmap shared object's hole part of PT_LOAD") #define DL_MAP_RESERVED_HUGEPAGE_AREA_ERROR \ N_("failed to map reserved 2MB contiguous hugepage va space") #define DL_FIND_EXEC_SEGMENT_ERROR \ diff --git a/elf/dl-map-segments-hugepage.h b/elf/dl-map-segments-hugepage.h index e7202131..a352c903 100644 --- a/elf/dl-map-segments-hugepage.h +++ b/elf/dl-map-segments-hugepage.h @@ -486,19 +486,6 @@ _mmap_segment(struct link_map *l, const struct loadcmd loadcmds[], size_t nloadc return NULL; } -static __always_inline void * -_mmap_hole(const struct loadcmd *current, const struct loadcmd *next, - ElfW(Addr) mapstart, size_t mapseglen, int fd) -{ - if (__glibc_unlikely (GLRO(dl_debug_mask) & DL_DEBUG_FILES)) - _dl_debug_printf("\tmmap hole area:[%lx-%lx)\n", mapstart + mapseglen, - mapstart + (next->mapstart - current->mapstart)); - return __mmap((void *)(mapstart + mapseglen), - next->mapstart - (current->mapstart + mapseglen), - PROT_NONE, MAP_FILE|MAP_PRIVATE|MAP_FIXED, - fd, current->mapoff + mapseglen); -} - static __always_inline const char * _dl_map_segments_largein (struct link_map *l, int fd, const ElfW(Ehdr) *header, int type, @@ -541,13 +528,6 @@ _dl_map_segments_largein (struct link_map *l, int fd, goto unmap_reserved_area; } - if (prev->mapstart + mapseglen < c->mapstart && - _mmap_hole(prev, c, map_addr, mapseglen, fd) == MAP_FAILED) - { - errstring = DL_MAP_SEGMENTS_ERROR_MAP_HOLE_FILL; - goto unmap_reserved_area; - } - map_addr += c->mapstart - prev->mapstart; errstring = _mmap_segment(l, loadcmds, nloadcmds, c, map_addr, fd, &mapseglen, hp_bitmap); @@ -582,12 +562,6 @@ _dl_map_segments_largein (struct link_map *l, int fd, goto unmap_reserved_area; } - if (c->mapstart + mapseglen < prev->mapstart && - _mmap_hole(c, prev, map_addr, mapseglen, fd) == MAP_FAILED) - { - errstring = DL_MAP_SEGMENTS_ERROR_MAP_HOLE_FILL; - goto unmap_reserved_area; - } prev = c; --c; } -- 2.38.1