From 49986b3674d002c43fa09e6b777555bdc772018b Mon Sep 17 00:00:00 2001 From: Lv Ying Date: Tue, 25 Jan 2022 09:29:32 +0000 Subject: [PATCH 3/3] elf/ld.so: use special mmap for hugepage to get symbols use special mmap for hugepage to get symbols in hugepage area for debug purpose; kernel need to support file mmap hugepage; --- elf/dl-load.h | 2 -- elf/dl-map-segments-hugepage.h | 25 +++---------------------- 2 files changed, 3 insertions(+), 24 deletions(-) diff --git a/elf/dl-load.h b/elf/dl-load.h index d3f69466..fcf91a47 100644 --- a/elf/dl-load.h +++ b/elf/dl-load.h @@ -134,8 +134,6 @@ static const char *_dl_map_segments (struct link_map *l, int fd, #ifdef HUGEPAGE_SHARED_LIB #define DL_MAP_SEGMENTS_ERROR_TYPE \ N_("cannot map Non shared object file in hugepage") -#define DL_MAP_SEGMENTS_ERROR_READ_SEGMENT \ - N_("failed to read shared object file") #define DL_MAP_SEGMENTS_ERROR_ARRANGE \ N_("shared object's PT_LOAD segment in wrong arrange") #define DL_MAP_SEGMENTS_ERROR_MAP_HOLE_FILL \ diff --git a/elf/dl-map-segments-hugepage.h b/elf/dl-map-segments-hugepage.h index cd7b6d79..37788ef9 100644 --- a/elf/dl-map-segments-hugepage.h +++ b/elf/dl-map-segments-hugepage.h @@ -302,33 +302,14 @@ _mmap_segment_filesz(struct link_map *l, const struct loadcmd *c, ElfW(Addr) map size_t mod = len % SIZE_2MB; if (__glibc_unlikely (GLRO(dl_debug_mask) & DL_DEBUG_FILES)) - _dl_debug_printf("\t\tmmap hugepage: [%lx-%lx)\n", mapstart, mapstart + len - mod); + _dl_debug_printf("\t\tmmap hugepage: [%lx-%lx), mapoff = %lx\n", mapstart, + mapstart + len - mod, c->mapoff + relro_len + prev_map_len); mapstart = (ElfW(Addr))__mmap((void *)mapstart, len - mod, c->prot, MAP_FIXED|MAP_PRIVATE|MAP_ANONYMOUS|MAP_HUGETLB|(SHFIT_2MB << MAP_HUGE_SHIFT), - -1, 0); + fd, c->mapoff + relro_len + prev_map_len); if (__glibc_unlikely ((void *)mapstart == MAP_FAILED)) return DL_MAP_SEGMENTS_ERROR_MAP_SEGMENT; - if ((c->prot & PROT_WRITE) == 0 && __mprotect((void *)mapstart, len - mod, c->prot | PROT_WRITE) < 0) - { - return DL_MAP_SEGMENTS_ERROR_MPROTECT; - } - - /* Read the segment contents from the file. */ - size_t file_len = (size_t)(c->dataend - c->mapstart) <= prev_map_len + relro_len ? 0 : - (size_t)(c->dataend - c->mapstart) - prev_map_len - relro_len; - if (file_len > 0) - { - lseek(fd, c->mapoff + relro_len + prev_map_len, SEEK_SET); - if ( __read(fd, (void *)mapstart, file_len < len - mod ? file_len : len - mod) < 0) - return DL_MAP_SEGMENTS_ERROR_READ_SEGMENT; - } - - if ((c->prot & PROT_WRITE) == 0 && __mprotect((void *)mapstart, len - mod, c->prot) < 0) - { - return DL_MAP_SEGMENTS_ERROR_MPROTECT; - } - map_addr = map_addr == 0 ? (void *)mapstart : map_addr; mapstart += len - mod; -- 2.31.1