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2012-05-23x86-32, relocs: Whitelist more symbols for ld bug workaroundH. Peter Anvin1-0/+11
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
2012-05-18x86, relocs: When printing an error, say relative or absoluteH. Peter Anvin1-3/+8
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>
2012-05-18x86, relocs: Workaround for binutils 2.22.52.0.1 section bugH. Peter Anvin1-1/+5
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>
2012-05-18x86, realmode: 16-bit real-mode code support for relocs toolH. Peter Anvin1-0/+797
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>
2012-05-18x86, relocs: When printing an error, say relative or absoluteH. Peter Anvin1-3/+8
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>
2012-05-18x86, relocs: More relocations which may end up as absoluteH. Peter Anvin1-1/+5
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 433de739bbc2 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>
2012-05-18x86, relocs: Workaround for binutils 2.22.52.0.1 section bugH. Peter Anvin1-1/+1
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>
2012-05-08x86, realmode: move relocs from scripts/ to arch/x86/toolsJarkko Sakkinen1-0/+804
Moved relocs tool from scripts/ to arch/x86/tools because it is architecture specific script. Added new target archscripts that can be used to build scripts needed building an architecture. Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@intel.com> Link: http://lkml.kernel.org/r/1336501366-28617-22-git-send-email-jarkko.sakkinen@intel.com Signed-off-by: H. Peter Anvin <hpa@linux.intel.com> Cc: Sam Ravnborg <sam@ravnborg.org> Cc: Michal Marek <mmarek@suse.cz>