As noted in checkin:
a3e854d95 x86, relocs: Workaround for binutils 2.22.52.0.1 section bug
ld version 2.22.52.0.[12] can incorrectly promote relative symbols to
absolute, if the output section they appear in is otherwise empty.
Since checkin:
6520fe55 x86, realmode: 16-bit real-mode code support for relocs tool
we actually check for this and error out rather than silently creating
a kernel which will malfunction if relocated.
Ingo found a configuration in which __start_builtin_fw triggered the
warning.
Go through the linker script sources and look for more symbols that
could plausibly get bogusly promoted to absolute, and add them to the
whitelist.
In general, if the following error triggers:
Invalid absolute R_386_32 relocation: <symbol>
... then we should verify that <symbol> is really meant to be
relocated, and add it and any related symbols manually to the S_REL
regexp.
Please note that 6520fe55 does not introduce the error, only the check
for the error -- without 6520fe55 this version of ld will simply
produce a corrupt kernel if CONFIG_RELOCATABLE is set on x86-32.
Reported-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Cc: <stable@vger.kernel.org> v3.4
When the relocs tool throws an error, let the error message say if it
is an absolute or relative symbol. This should make it a lot more
clear what action the programmer needs to take and should help us find
the reason if additional symbol bugs show up.
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Cc: <stable@vger.kernel.org>
GNU ld 2.22.52.0.1 has a bug that it blindly changes symbols from
section-relative to absolute if they are in a section of zero length.
This turns the symbols __init_begin and __init_end into absolute
symbols. Let the relocs program know that those should be treated as
relative symbols.
Reported-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Cc: H.J. Lu <hjl.tools@gmail.com>
Cc: <stable@vger.kernel.org>
Cc: Jarkko Sakkinen <jarkko.sakkinen@intel.com>
A new option is added to the relocs tool called '--realmode'.
This option causes the generation of 16-bit segment relocations
and 32-bit linear relocations for the real-mode code. When
the real-mode code is moved to the low-memory during kernel
initialization, these relocation entries can be used to
relocate the code properly.
In the assembly code 16-bit segment relocations must be relative
to the 'real_mode_seg' absolute symbol. Linear relocations must be
relative to a symbol prefixed with 'pa_'.
16-bit segment relocation is used to load cs:ip in 16-bit code.
Linear relocations are used in the 32-bit code for relocatable
data references. They are declared in the linker script of the
real-mode code.
The relocs tool is moved to arch/x86/tools/relocs.c, and added new
target archscripts that can be used to build scripts needed building
an architecture. be compiled before building the arch/x86 tree.
[ hpa: accelerating this because it detects invalid absolute
relocations, a serious bug in binutils 2.22.52.0.x which currently
produces bad kernels. ]
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Link: http://lkml.kernel.org/r/1336501366-28617-2-git-send-email-jarkko.sakkinen@intel.com
Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@intel.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Cc: <stable@vger.kernel.org>
When the relocs tool throws an error, let the error message say if it
is an absolute or relative symbol. This should make it a lot more
clear what action the programmer needs to take.
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
GNU ld 2.22.52.0.1 has a bug that it blindly changes symbols from
section-relative to absolute if they are in a section of zero length.
This turns the symbols __init_begin and __init_end into absolute
symbols. Let the relocs program know that those should be treated as
relative symbols.
This bug is exposed by checkin
433de739bb x86, realmode: 16-bit real-mode code support for relocs tool
only in the sense that that checkin changes the relocs tool to report
an error instead of silently generating a kernel which is broken if
relocated.
Reported-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Cc: H.J. Lu <hjl.tools@gmail.com>
Cc: Jarkko Sakkinen <jarkko.sakkinen@intel.com>
GNU ld 2.22.52.0.1 has a bug that it blindly changes symbols from
section-relative to absolute if they are in a section of zero length.
This turns the symbols __init_begin and __init_end into absolute
symbols. Let the relocs program know that those should be treated as
relative symbols.
Reported-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Cc: H.J. Lu <hjl.tools@gmail.com>
It says
Warning: objdump version is older than 2.19
Warning: Skipping posttest.
because it used the wrong field from `objdump -v':
akpm:/usr/src/25> /opt/crosstool/gcc-4.0.2-glibc-2.3.6/x86_64-unknown-linux-gnu/bin/x86_64-unknown-linux-gnu-objdump -v
GNU objdump 2.16.1
Copyright 2005 Free Software Foundation, Inc.
This program is free software; you may redistribute it under the terms of
the GNU General Public License. This program has absolutely no warranty.
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
LKML-Reference: <200912172326.nBHNQaQl024796@imap1.linux-foundation.org>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Cc: Masami Hiramatsu <mhiramat@redhat.com>
Not all awk implementations (including the default awk in Ubuntu 9.10)
support POSIX character classes. Since x86-opcode-map.txt is plain
ASCII, we can just use explicit ranges for lower case, alphabetic, and
alphanumeric characters instead.
Signed-off-by: Roland Dreier <rolandd@cisco.com>
Acked-by: Masami Hiramatsu <mhiramat@redhat.com>
LKML-Reference: <adabphy750b.fsf@roland-alpha.cisco.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
* 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
x86: Fix kprobes build with non-gawk awk
x86: Split swiotlb initialization into two stages
x86: Regex support and known-movable symbols for relocs, fix _end
x86, msr: Remove incorrect, duplicated code in the MSR driver
x86: Merge kernel_thread()
x86: Sync 32/64-bit kernel_thread
x86, 32-bit: Use same regs as 64-bit for kernel_thread_helper
x86, 64-bit: Use user_mode() to determine new stack pointer in copy_thread()
x86, 64-bit: Move kernel_thread to C
x86-64, paravirt: Call set_iopl_mask() on 64 bits
x86-32: Avoid pipeline serialization in PTREGSCALL1 and 2
x86: Merge sys_clone
x86, 32-bit: Convert sys_vm86 & sys_vm86old
x86: Merge sys_sigaltstack
x86: Merge sys_execve
x86: Merge sys_iopl
x86-32: Add new pt_regs stubs
cpumask: Use modern cpumask style in arch/x86/kernel/cpu/mcheck/mce-inject.c
The instruction attribute table generator fails when run by mawk
or original-awk:
$ mawk -f arch/x86/tools/gen-insn-attr-x86.awk \
arch/x86/lib/x86-opcode-map.txt > /dev/null
Semantic error at 240: Second IMM error
$ echo $?
1
Line 240 contains "c8: ENTER Iw,Ib", which indicates that this
instruction has two immediate operands, the second of which is
one byte. The script loops through the immediate operands using
a for loop.
Unfortunately, there is no guarantee in awk that a for (variable
in array) loop will return the indices in increasing order.
Internally, both original-awk and mawk iterate over a hash table
for this purpose, and both implementations happen to produce the
index 2 before 1. The supposed second immediate operand is more
than one byte wide, producing the error.
So loop over the indices in increasing order instead. As a
side-effect, with mawk this means the silly two-entry hash table
never has to be built.
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Acked-by Masami Hiramatsu <mhiramat@redhat.com>
Cc: Jim Keniston <jkenisto@us.ibm.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <20091213220437.GA27718@progeny.tock>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Fix the following warning:
arch/x86/tools/test_get_len.c: In function "main":
arch/x86/tools/test_get_len.c:116: warning: unused variable "c"
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Cc: Masami Hiramatsu <mhiramat@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Add x86 instruction decoder to arch-specific libraries. This decoder
can decode x86 instructions used in kernel into prefix, opcode, modrm,
sib, displacement and immediates. This can also show the length of
instructions.
This version introduces instruction attributes for decoding
instructions.
The instruction attribute tables are generated from the opcode map file
(x86-opcode-map.txt) by the generator script(gen-insn-attr-x86.awk).
Currently, the opcode maps are based on opcode maps in Intel(R) 64 and
IA-32 Architectures Software Developers Manual Vol.2: Appendix.A,
and consist of below two types of opcode tables.
1-byte/2-bytes/3-bytes opcodes, which has 256 elements, are
written as below;
Table: table-name
Referrer: escaped-name
opcode: mnemonic|GrpXXX [operand1[,operand2...]] [(extra1)[,(extra2)...] [| 2nd-mnemonic ...]
(or)
opcode: escape # escaped-name
EndTable
Group opcodes, which has 8 elements, are written as below;
GrpTable: GrpXXX
reg: mnemonic [operand1[,operand2...]] [(extra1)[,(extra2)...] [| 2nd-mnemonic ...]
EndTable
These opcode maps include a few SSE and FP opcodes (for setup), because
those opcodes are used in the kernel.
Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com>
Signed-off-by: Jim Keniston <jkenisto@us.ibm.com>
Acked-by: H. Peter Anvin <hpa@zytor.com>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Avi Kivity <avi@redhat.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Frank Ch. Eigler <fche@redhat.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Jason Baron <jbaron@redhat.com>
Cc: K.Prasad <prasad@linux.vnet.ibm.com>
Cc: Lai Jiangshan <laijs@cn.fujitsu.com>
Cc: Li Zefan <lizf@cn.fujitsu.com>
Cc: Przemysław Pawełczyk <przemyslaw@pawelczyk.it>
Cc: Roland McGrath <roland@redhat.com>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Tom Zanussi <tzanussi@gmail.com>
Cc: Vegard Nossum <vegard.nossum@gmail.com>
LKML-Reference: <20090813203413.31965.49709.stgit@localhost.localdomain>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
