dvlahovski created this revision.
dvlahovski added a reviewer: labath.
dvlahovski added a subscriber: lldb-commits.
The binary layout of prstatus and prpsinfo was wrong.
Some of the member variables where not aligned properly
and others where with a wrong type (e.g. the time related
stuff in prstatus).
I used the structs defined in bfd in binutils to see what the layout
of the elf-core format in these section is.
(https://sourceware.org/git/?p=binutils-gdb.git;a=blob;f=bfd/hosts/x86-64linux.h;h=4e420a1f2081dd3b51f5d6b7a8e4093580f5cdb5;hb=master)
Note: those structures are only for x86 64 bit elf-core files
This shouldn't have any impact on the functionality, because
lldb actually uses only a few of the member variables of those structs
and they are with a correct type and alignment.
I found this while trying to add/fix the support for
i386 core files (https://llvm.org/bugs/show_bug.cgi?id=26947)
https://reviews.llvm.org/D22628
Files:
source/Plugins/Process/elf-core/ThreadElfCore.cpp
source/Plugins/Process/elf-core/ThreadElfCore.h
Index: source/Plugins/Process/elf-core/ThreadElfCore.h
===================================================================
--- source/Plugins/Process/elf-core/ThreadElfCore.h
+++ source/Plugins/Process/elf-core/ThreadElfCore.h
@@ -21,17 +21,13 @@
struct compat_timeval
{
- int64_t tv_sec;
- int32_t tv_usec;
+ alignas(8) uint64_t tv_sec;
+ alignas(8) uint64_t tv_usec;
};
// PRSTATUS structure's size differs based on architecture.
// Currently parsing done only for x86-64 architecture by
// simply reading data from the buffer.
-// The following macros are used to specify the size.
-// Calculating size using sizeof() wont work because of padding.
-#define ELFLINUXPRSTATUS64_SIZE (112)
-#define ELFLINUXPRPSINFO64_SIZE (132)
#undef si_signo
#undef si_code
@@ -70,28 +66,30 @@
{
case lldb_private::ArchSpec::eCore_s390x_generic:
case lldb_private::ArchSpec::eCore_x86_64_x86_64:
- return ELFLINUXPRSTATUS64_SIZE;
+ return sizeof(ELFLinuxPrStatus);
default:
return 0;
}
}
};
+static_assert(sizeof(ELFLinuxPrStatus) == 112, "sizeof ELFLinuxPrStatus is not correct!");
+
struct ELFLinuxPrPsInfo
{
- char pr_state;
- char pr_sname;
- char pr_zomb;
- char pr_nice;
- uint64_t pr_flag;
- uint32_t pr_uid;
- uint32_t pr_gid;
- int32_t pr_pid;
- int32_t pr_ppid;
- int32_t pr_pgrp;
- int32_t pr_sid;
- char pr_fname[16];
- char pr_psargs[80];
+ char pr_state;
+ char pr_sname;
+ char pr_zomb;
+ char pr_nice;
+ alignas(8) uint64_t pr_flag;
+ uint32_t pr_uid;
+ uint32_t pr_gid;
+ int32_t pr_pid;
+ int32_t pr_ppid;
+ int32_t pr_pgrp;
+ int32_t pr_sid;
+ char pr_fname[16];
+ char pr_psargs[80];
ELFLinuxPrPsInfo();
@@ -105,13 +103,15 @@
{
case lldb_private::ArchSpec::eCore_s390x_generic:
case lldb_private::ArchSpec::eCore_x86_64_x86_64:
- return ELFLINUXPRPSINFO64_SIZE;
+ return sizeof(ELFLinuxPrPsInfo);
default:
return 0;
}
}
};
+static_assert(sizeof(ELFLinuxPrPsInfo) == 136, "sizeof ELFLinuxPrPsInfo is not correct!");
+
struct ThreadData
{
lldb_private::DataExtractor gpregset;
Index: source/Plugins/Process/elf-core/ThreadElfCore.cpp
===================================================================
--- source/Plugins/Process/elf-core/ThreadElfCore.cpp
+++ source/Plugins/Process/elf-core/ThreadElfCore.cpp
@@ -228,8 +228,8 @@
{
case ArchSpec::eCore_s390x_generic:
case ArchSpec::eCore_x86_64_x86_64:
- len = data.ExtractBytes(0, ELFLINUXPRSTATUS64_SIZE, byteorder, this);
- return len == ELFLINUXPRSTATUS64_SIZE;
+ len = data.ExtractBytes(0, sizeof(ELFLinuxPrStatus), byteorder, this);
+ return len == sizeof(ELFLinuxPrStatus);
default:
return false;
}
@@ -252,8 +252,8 @@
{
case ArchSpec::eCore_s390x_generic:
case ArchSpec::eCore_x86_64_x86_64:
- len = data.ExtractBytes(0, ELFLINUXPRPSINFO64_SIZE, byteorder, this);
- return len == ELFLINUXPRPSINFO64_SIZE;
+ len = data.ExtractBytes(0, sizeof(ELFLinuxPrPsInfo), byteorder, this);
+ return len == sizeof(ELFLinuxPrPsInfo);
default:
return false;
}
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