70 lines
1.9 KiB
Diff
70 lines
1.9 KiB
Diff
From 968c983d43bc51f719f3e7a0fcb1bb8669b5f7c4 Mon Sep 17 00:00:00 2001
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From: "H.J. Lu" <hjl.tools@gmail.com>
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Date: Wed, 20 Dec 2023 19:42:12 -0800
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Subject: [PATCH 5/9] x86-64: Fix the tcb field load for x32 [BZ #31185]
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_dl_tlsdesc_undefweak and _dl_tlsdesc_dynamic access the thread pointer
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via the tcb field in TCB:
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_dl_tlsdesc_undefweak:
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_CET_ENDBR
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movq 8(%rax), %rax
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subq %fs:0, %rax
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ret
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_dl_tlsdesc_dynamic:
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...
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subq %fs:0, %rax
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movq -8(%rsp), %rdi
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ret
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Since the tcb field in TCB is a pointer, %fs:0 is a 32-bit location,
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not 64-bit. It should use "sub %fs:0, %RAX_LP" instead. Since
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_dl_tlsdesc_undefweak returns ptrdiff_t and _dl_make_tlsdesc_dynamic
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returns void *, RAX_LP is appropriate here for x32 and x86-64. This
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fixes BZ #31185.
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(cherry picked from commit 81be2a61dafc168327c1639e97b6dae128c7ccf3)
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---
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NEWS | 1 +
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sysdeps/x86_64/dl-tlsdesc.S | 4 ++--
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2 files changed, 3 insertions(+), 2 deletions(-)
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diff --git a/NEWS b/NEWS
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index 71057e4793..6fbb8a9e1d 100644
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--- a/NEWS
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+++ b/NEWS
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@@ -38,6 +38,7 @@ The following bugs are resolved with this release:
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-D_FILE_OFFSET_BITS=64
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[30842] Stack read overflow in getaddrinfo in no-aaaa mode (CVE-2023-4527)
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[31184] FAIL: elf/tst-tlsgap
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+ [31185] Incorrect thread point access in _dl_tlsdesc_undefweak and _dl_tlsdesc_dynamic
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Version 2.38
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diff --git a/sysdeps/x86_64/dl-tlsdesc.S b/sysdeps/x86_64/dl-tlsdesc.S
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index c4823547d7..4579424bf7 100644
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--- a/sysdeps/x86_64/dl-tlsdesc.S
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+++ b/sysdeps/x86_64/dl-tlsdesc.S
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@@ -61,7 +61,7 @@ _dl_tlsdesc_return:
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_dl_tlsdesc_undefweak:
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_CET_ENDBR
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movq 8(%rax), %rax
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- subq %fs:0, %rax
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+ sub %fs:0, %RAX_LP
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ret
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cfi_endproc
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.size _dl_tlsdesc_undefweak, .-_dl_tlsdesc_undefweak
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@@ -116,7 +116,7 @@ _dl_tlsdesc_dynamic:
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addq TLSDESC_MODOFF(%rdi), %rax
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.Lret:
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movq -16(%rsp), %rsi
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- subq %fs:0, %rax
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+ sub %fs:0, %RAX_LP
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movq -8(%rsp), %rdi
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ret
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.Lslow:
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--
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2.33.0
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