From edd53cb652a2e4f44f56a1fe032b8ca15bffbb46 Mon Sep 17 00:00:00 2001 From: Francis Ricci Date: Tue, 11 Jul 2017 19:40:53 +0000 Subject: [PATCH] Inline function to get mac segment address range Summary: This function is only called once and is fairly simple. Inline to keep API simple. Reviewers: alekseyshl, kubamracek Subscribers: llvm-commits Differential Revision: https://reviews.llvm.org/D35270 llvm-svn: 307695 --- .../lib/sanitizer_common/sanitizer_procmaps.h | 2 - .../sanitizer_procmaps_mac.cc | 119 +++++++++--------- 2 files changed, 58 insertions(+), 63 deletions(-) diff --git a/compiler-rt/lib/sanitizer_common/sanitizer_procmaps.h b/compiler-rt/lib/sanitizer_common/sanitizer_procmaps.h index a0ac0b9196c3..06d072b4dc77 100644 --- a/compiler-rt/lib/sanitizer_common/sanitizer_procmaps.h +++ b/compiler-rt/lib/sanitizer_common/sanitizer_procmaps.h @@ -86,8 +86,6 @@ class MemoryMappingLayout { # elif SANITIZER_MAC template bool NextSegmentLoad(MemoryMappedSegment *segment); - void GetSegmentAddrRange(MemoryMappedSegment *segment, uptr vmaddr, - uptr vmsize); int current_image_; u32 current_magic_; u32 current_filetype_; diff --git a/compiler-rt/lib/sanitizer_common/sanitizer_procmaps_mac.cc b/compiler-rt/lib/sanitizer_common/sanitizer_procmaps_mac.cc index 037022ee314d..560451a16d90 100644 --- a/compiler-rt/lib/sanitizer_common/sanitizer_procmaps_mac.cc +++ b/compiler-rt/lib/sanitizer_common/sanitizer_procmaps_mac.cc @@ -88,6 +88,48 @@ void MemoryMappingLayout::LoadFromCache() { // No-op on Mac for now. } +// _dyld_get_image_header() and related APIs don't report dyld itself. +// We work around this by manually recursing through the memory map +// until we hit a Mach header matching dyld instead. These recurse +// calls are expensive, but the first memory map generation occurs +// early in the process, when dyld is one of the only images loaded, +// so it will be hit after only a few iterations. +static mach_header *get_dyld_image_header() { + mach_port_name_t port; + if (task_for_pid(mach_task_self(), internal_getpid(), &port) != + KERN_SUCCESS) { + return nullptr; + } + + unsigned depth = 1; + vm_size_t size = 0; + vm_address_t address = 0; + kern_return_t err = KERN_SUCCESS; + mach_msg_type_number_t count = VM_REGION_SUBMAP_INFO_COUNT_64; + + while (true) { + struct vm_region_submap_info_64 info; + err = vm_region_recurse_64(port, &address, &size, &depth, + (vm_region_info_t)&info, &count); + if (err != KERN_SUCCESS) return nullptr; + + if (size >= sizeof(mach_header) && info.protection & kProtectionRead) { + mach_header *hdr = (mach_header *)address; + if ((hdr->magic == MH_MAGIC || hdr->magic == MH_MAGIC_64) && + hdr->filetype == MH_DYLINKER) { + return hdr; + } + } + address += size; + } +} + +const mach_header *get_dyld_hdr() { + if (!dyld_hdr) dyld_hdr = get_dyld_image_header(); + + return dyld_hdr; +} + // Next and NextSegmentLoad were inspired by base/sysinfo.cc in // Google Perftools, https://github.com/gperftools/gperftools. @@ -101,7 +143,22 @@ bool MemoryMappingLayout::NextSegmentLoad(MemoryMappedSegment *segment) { current_load_cmd_addr_ += ((const load_command *)lc)->cmdsize; if (((const load_command *)lc)->cmd == kLCSegment) { const SegmentCommand* sc = (const SegmentCommand *)lc; - GetSegmentAddrRange(segment, sc->vmaddr, sc->vmsize); + + if (current_image_ == kDyldImageIdx) { + // vmaddr is masked with 0xfffff because on macOS versions < 10.12, + // it contains an absolute address rather than an offset for dyld. + // To make matters even more complicated, this absolute address + // isn't actually the absolute segment address, but the offset portion + // of the address is accurate when combined with the dyld base address, + // and the mask will give just this offset. + segment->start = (sc->vmaddr & 0xfffff) + (uptr)get_dyld_hdr(); + segment->end = (sc->vmaddr & 0xfffff) + sc->vmsize + (uptr)get_dyld_hdr(); + } else { + const sptr dlloff = _dyld_get_image_vmaddr_slide(current_image_); + segment->start = sc->vmaddr + dlloff; + segment->end = sc->vmaddr + sc->vmsize + dlloff; + } + // Return the initial protection. segment->protection = sc->initprot; segment->offset = @@ -174,66 +231,6 @@ static bool IsModuleInstrumented(const load_command *first_lc) { return false; } -// _dyld_get_image_header() and related APIs don't report dyld itself. -// We work around this by manually recursing through the memory map -// until we hit a Mach header matching dyld instead. These recurse -// calls are expensive, but the first memory map generation occurs -// early in the process, when dyld is one of the only images loaded, -// so it will be hit after only a few iterations. -static mach_header *get_dyld_image_header() { - mach_port_name_t port; - if (task_for_pid(mach_task_self(), internal_getpid(), &port) != - KERN_SUCCESS) { - return nullptr; - } - - unsigned depth = 1; - vm_size_t size = 0; - vm_address_t address = 0; - kern_return_t err = KERN_SUCCESS; - mach_msg_type_number_t count = VM_REGION_SUBMAP_INFO_COUNT_64; - - while (true) { - struct vm_region_submap_info_64 info; - err = vm_region_recurse_64(port, &address, &size, &depth, - (vm_region_info_t)&info, &count); - if (err != KERN_SUCCESS) return nullptr; - - if (size >= sizeof(mach_header) && info.protection & kProtectionRead) { - mach_header *hdr = (mach_header *)address; - if ((hdr->magic == MH_MAGIC || hdr->magic == MH_MAGIC_64) && - hdr->filetype == MH_DYLINKER) { - return hdr; - } - } - address += size; - } -} - -const mach_header *get_dyld_hdr() { - if (!dyld_hdr) dyld_hdr = get_dyld_image_header(); - - return dyld_hdr; -} - -void MemoryMappingLayout::GetSegmentAddrRange(MemoryMappedSegment *segment, - uptr vmaddr, uptr vmsize) { - if (current_image_ == kDyldImageIdx) { - // vmaddr is masked with 0xfffff because on macOS versions < 10.12, - // it contains an absolute address rather than an offset for dyld. - // To make matters even more complicated, this absolute address - // isn't actually the absolute segment address, but the offset portion - // of the address is accurate when combined with the dyld base address, - // and the mask will give just this offset. - segment->start = (vmaddr & 0xfffff) + (uptr)get_dyld_hdr(); - segment->end = (vmaddr & 0xfffff) + vmsize + (uptr)get_dyld_hdr(); - } else { - const sptr dlloff = _dyld_get_image_vmaddr_slide(current_image_); - segment->start = vmaddr + dlloff; - segment->end = vmaddr + vmsize + dlloff; - } -} - bool MemoryMappingLayout::Next(MemoryMappedSegment *segment) { for (; current_image_ >= kDyldImageIdx; current_image_--) { const mach_header *hdr = (current_image_ == kDyldImageIdx)