| c51ac8ac9a82d4883c9b62247cca98195da8cd63 |
|
24-May-2012 |
H. Peter Anvin <hpa@zytor.com> |
x86, relocs: Add jiffies and jiffies_64 to the relative whitelist
commit ea17e7414bc62e8d3bde8d08e3df1d921c518c17 upstream.
The symbol jiffies is created in the linker script as an alias to
jiffies_64. Unfortunately this is done outside any section, and
apparently GNU ld 2.21 doesn't carry the section with it, so we end up
with an absolute symbol and therefore a broken kernel.
Add jiffies and jiffies_64 to the whitelist.
The most disturbing bit with this discovery is that it shows that we
have had multiple linker bugs in this area crossing multiple
generations, and have been silently building bad kernels for some time.
Link: http://lkml.kernel.org/r/20120524171604.0d98284f3affc643e9714470@canb.auug.org.au
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
/arch/x86/tools/relocs.c
|
| 3c47c685100285be39ff7e347f762480b448b956 |
|
23-May-2012 |
H. Peter Anvin <hpa@zytor.com> |
x86-32, relocs: Whitelist more symbols for ld bug workaround
commit fd952815307f0f272bf49fd364a7fd2f9992bc42 upstream.
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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
/arch/x86/tools/relocs.c
|
| 24ab82bd9bf18f3efc69a131d73577940941e1b7 |
|
18-May-2012 |
H. Peter Anvin <hpa@linux.intel.com> |
x86, relocs: When printing an error, say relative or absolute
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>
/arch/x86/tools/relocs.c
|
| a3e854d95a76862cd37937e0b0438f540536771a |
|
18-May-2012 |
H. Peter Anvin <hpa@linux.intel.com> |
x86, relocs: Workaround for binutils 2.22.52.0.1 section bug
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>
/arch/x86/tools/relocs.c
|
| 6520fe5564acf07ade7b18a1272db1184835c487 |
|
08-May-2012 |
H. Peter Anvin <hpa@linux.intel.com> |
x86, realmode: 16-bit real-mode code support for relocs tool
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>
/arch/x86/tools/relocs.c
|