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authorH.J. Lu <hjl.tools@gmail.com>2018-06-12 06:23:28 -0700
committerH.J. Lu <hjl.tools@gmail.com>2018-06-12 06:34:48 -0700
commit0221ce2a90be2d40fc90f0b5dcec77a1ec013f53 (patch)
treefbdeebdceffa155aee874f4840861b4e795b810e
parente826574c985a15a500262f2fbd21c7e9259d3d11 (diff)
downloadglibc-0221ce2a90be2d40fc90f0b5dcec77a1ec013f53.tar.gz
i386: Change offset of __private_ss to 0x30 [BZ #23250]
sysdeps/i386/nptl/tls.h has typedef struct { void *tcb; /* Pointer to the TCB. Not necessarily the thread descriptor used by libpthread. */ dtv_t *dtv; void *self; /* Pointer to the thread descriptor. */ int multiple_threads; uintptr_t sysinfo; uintptr_t stack_guard; uintptr_t pointer_guard; int gscope_flag; int __glibc_reserved1; /* Reservation of some values for the TM ABI. */ void *__private_tm[4]; /* GCC split stack support. */ void *__private_ss; } tcbhead_t; The offset of __private_ss is 0x34. But GCC defines /* We steal the last transactional memory word. */ #define TARGET_THREAD_SPLIT_STACK_OFFSET 0x30 and libgcc/config/i386/morestack.S has cmpl %gs:0x30,%eax # See if we have enough space. movl %eax,%gs:0x30 # Save the new stack boundary. movl %eax,%gs:0x30 # Save the new stack boundary. movl %ecx,%gs:0x30 # Save new stack boundary. movl %eax,%gs:0x30 movl %gs:0x30,%eax movl %eax,%gs:0x30 Since update TARGET_THREAD_SPLIT_STACK_OFFSET changes split stack ABI, this patch updates tcbhead_t to match GCC. [BZ #23250] [BZ #10686] * sysdeps/i386/nptl/tls.h (tcbhead_t): Change __private_tm[4] to _private_tm[3] and add __glibc_reserved2. Add _Static_assert of offset of __private_ss == 0x30. * sysdeps/x86_64/nptl/tls.h: Add _Static_assert of offset of __private_ss == 0x40 for ILP32 and == 0x70 for LP64.
-rw-r--r--ChangeLog10
-rw-r--r--sysdeps/i386/nptl/tls.h7
-rw-r--r--sysdeps/x86_64/nptl/tls.h10
3 files changed, 26 insertions, 1 deletions
diff --git a/ChangeLog b/ChangeLog
index c1b9cdfd29..c1ff22b191 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,13 @@
+2018-06-12 H.J. Lu <hongjiu.lu@intel.com>
+
+ [BZ #23250]
+ [BZ #10686]
+ * sysdeps/i386/nptl/tls.h (tcbhead_t): Change __private_tm[4]
+ to _private_tm[3] and add __glibc_reserved2.
+ Add _Static_assert of offset of __private_ss == 0x30.
+ * sysdeps/x86_64/nptl/tls.h: Add _Static_assert of offset of
+ __private_ss == 0x40 for ILP32 and == 0x70 for LP64.
+
2018-06-12 Florian Weimer <fweimer@redhat.com>
x86: Make strncmp usable from rtld.
diff --git a/sysdeps/i386/nptl/tls.h b/sysdeps/i386/nptl/tls.h
index 6c36e58e9c..afb71ce431 100644
--- a/sysdeps/i386/nptl/tls.h
+++ b/sysdeps/i386/nptl/tls.h
@@ -43,11 +43,16 @@ typedef struct
int gscope_flag;
int __glibc_reserved1;
/* Reservation of some values for the TM ABI. */
- void *__private_tm[4];
+ void *__private_tm[3];
/* GCC split stack support. */
void *__private_ss;
+ void *__glibc_reserved2;
} tcbhead_t;
+/* morestack.S in libgcc uses offset 0x30 to access __private_ss, */
+_Static_assert (offsetof (tcbhead_t, __private_ss) == 0x30,
+ "offset of __private_ss != 0x30");
+
# define TLS_MULTIPLE_THREADS_IN_TCB 1
#else /* __ASSEMBLER__ */
diff --git a/sysdeps/x86_64/nptl/tls.h b/sysdeps/x86_64/nptl/tls.h
index 6da1c04a98..65c0051dcf 100644
--- a/sysdeps/x86_64/nptl/tls.h
+++ b/sysdeps/x86_64/nptl/tls.h
@@ -65,6 +65,16 @@ typedef struct
void *__padding[8];
} tcbhead_t;
+# ifdef __ILP32__
+/* morestack.S in libgcc uses offset 0x40 to access __private_ss, */
+_Static_assert (offsetof (tcbhead_t, __private_ss) == 0x40,
+ "offset of __private_ss != 0x40");
+# else
+/* morestack.S in libgcc uses offset 0x70 to access __private_ss, */
+_Static_assert (offsetof (tcbhead_t, __private_ss) == 0x70,
+ "offset of __private_ss != 0x70");
+# endif
+
#else /* __ASSEMBLER__ */
# include <tcb-offsets.h>
#endif