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2011-08-23ARM: 7059/1: LPAE: Use PMD_(SHIFT|SIZE|MASK) instead of PGDIR_*Catalin Marinas
PGDIR_SHIFT and PMD_SHIFT for the classic 2-level page table format have the same value (21). This patch converts the PGDIR_* uses in the kernel to the PMD_* equivalent so that LPAE builds can reuse the same code. Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-08-04ARM: Fix build error for SMP=n buildsRussell King
Unfortunately, the module fixups cause the kernel to fail to build when SMP is not enabled. Fix this by removing the reference to fixup_smp on non-SMP fixup kernels, but ensuring that if we do have the SMP fixup section, we refuse to load the module. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-07-24modules: make arch's use default loader hooksJonas Bonn
This patch removes all the module loader hook implementations in the architecture specific code where the functionality is the same as that now provided by the recently added default hooks. Signed-off-by: Jonas Bonn <jonas@southpole.se> Acked-by: Mike Frysinger <vapier@gentoo.org> Acked-by: Geert Uytterhoeven <geert@linux-m68k.org> Tested-by: Michal Simek <monstr@monstr.eu> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2011-06-17ARM: 6963/1: Thumb-2: Relax relocation requirements for non-function symbolsDave Martin
The "Thumb bit" of a symbol is only really meaningful for function symbols (STT_FUNC). However, sometimes a branch is relocated against a non-function symbol; for example, PC-relative branches to anonymous assembler local symbols are typically fixed up against the start-of-section symbol, which is not a function symbol. Some inline assembler generates references of this type, such as fixup code generated by macros in <asm/uaccess.h>. The existing relocation code for R_ARM_THM_CALL/R_ARM_THM_JUMP24 interprets this case as an error, because the target symbol appears to be an ARM symbol; but this is really not the case, since the target symbol is just a base in these cases. The addend defines the precise offset to the target location, but since the addend is encoded in a non-interworking Thumb branch instruction, there is no explicit Thumb bit in the addend. Because these instructions never interwork, the implied Thumb bit in the addend is 1, and the destination is Thumb by definition. This patch removes the extraneous Thumb bit check for non-function symbols, enabling modules containing the affected relocation types to be loaded. No modification to the actual relocation code is required, since this code does not take bit[0] of the location->destination offset into account in any case. Function symbols are always checked for interworking conflicts, as before. Signed-off-by: Dave Martin <dave.martin@linaro.org> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-03-16Merge branch 'p2v' into develRussell King
Conflicts: arch/arm/kernel/module.c arch/arm/mach-s5pv210/sleep.S
2011-03-16Merge branch 'misc' into develRussell King
Conflicts: arch/arm/Kconfig
2011-02-23ARM: improve module relocation fixup diagnosticsRussell King
Current diagnostics are rather poor when things go wrong: ipv6: relocation out of range, section 2 reloc 0 sym 'snmp_mib_free' Let's include a little more information about the problem: ipv6: section 2 reloc 0 sym 'snmp_mib_free': relocation 28 out of range (0xbf0000a4 -> 0xc11b4858) so that we show exactly what the problem is - not only what type of relocation but also the offending address range too. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-02-17ARM: P2V: introduce phys_to_virt/virt_to_phys runtime patchingRussell King
This idea came from Nicolas, Eric Miao produced an initial version, which was then rewritten into this. Patch the physical to virtual translations at runtime. As we modify the code, this makes it incompatible with XIP kernels, but allows us to achieve this with minimal loss of performance. As many translations are of the form: physical = virtual + (PHYS_OFFSET - PAGE_OFFSET) virtual = physical - (PHYS_OFFSET - PAGE_OFFSET) we generate an 'add' instruction for __virt_to_phys(), and a 'sub' instruction for __phys_to_virt(). We calculate at run time (PHYS_OFFSET - PAGE_OFFSET) by comparing the address prior to MMU initialization with where it should be once the MMU has been initialized, and place this constant into the above add/sub instructions. Once we have (PHYS_OFFSET - PAGE_OFFSET), we can calculate the real PHYS_OFFSET as PAGE_OFFSET is a build-time constant, and save this for the C-mode PHYS_OFFSET variable definition to use. At present, we are unable to support Realview with Sparsemem enabled as this uses a complex mapping function, and MSM as this requires a constant which will not fit in our math instruction. Add a module version magic string for this feature to prevent incompatible modules being loaded. Tested-by: Tony Lindgren <tony@atomide.com> Reviewed-by: Nicolas Pitre <nicolas.pitre@linaro.org> Tested-by: Nicolas Pitre <nicolas.pitre@linaro.org> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-02-10ARM: fixup SMP alternatives in modulesRussell King
With certain configurations, we inline the unlock functions in modules, which results in SMP alternatives being created in modules. We need to fix those up when loading a module to prevent undefined instruction faults. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-01-13mm: unify module_alloc code for vmallocDavid Rientjes
Four architectures (arm, mips, sparc, x86) use __vmalloc_area() for module_init(). Much of the code is duplicated and can be generalized in a globally accessible function, __vmalloc_node_range(). __vmalloc_node() now calls into __vmalloc_node_range() with a range of [VMALLOC_START, VMALLOC_END) for functionally equivalent behavior. Each architecture may then use __vmalloc_node_range() directly to remove the duplication of code. Signed-off-by: David Rientjes <rientjes@google.com> Cc: Christoph Lameter <cl@linux.com> Cc: Russell King <linux@arm.linux.org.uk> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: "David S. Miller" <davem@davemloft.net> Cc: Ingo Molnar <mingo@redhat.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-12-01ARM: module: ignore unwind for sections not marked SHF_ALLOCRussell King
If a section is not marked with SHF_ALLOC, it will be discarded by the module code. Therefore, it is not correct to register the unwind tables. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2010-12-01ARM: module: clean up handling of ELF unwind tablesRussell King
There's no need to keep pointers to the ELF sections available while the module is loaded - we only need the section pointers while we're finding and registering the unwind tables, which can all be done during the finalize stage of loading. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2010-09-02ARM: 6340/1: module - additional unwind tables for exit/devexit sectionsPhil Carmody
Without these, exit functions cannot be stack-traced, so to speak. This implies that module unloads that perform allocations (don't laugh) will cause noisy warnings on the console when kmemleak is enabled, as it presumes that all code's call chains are traceable. Similarly, BUGs and WARN_ONs will give additional console spam. Signed-off-by: Phil Carmody <ext-phil.2.carmody@nokia.com> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2010-09-02ARM: 6339/1: module - simplify unwind table handlingPhil Carmody
The various sections are all dealt with similarly, so factor out that common behaviour. (Incorporating Peter Huewe's fix.) Cc: Peter Huewe <peterhuewe@gmx.de> Signed-off-by: Phil Carmody <ext-phil.2.carmody@nokia.com> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2010-09-02ARM: 6338/1: module - simplify code with temporariesPhil Carmody
Less to read. Signed-off-by: Phil Carmody <ext-phil.2.carmody@nokia.com> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2010-08-05ARM: 6191/1: Do not compile the Thumb-2 module relocations on an ARM kernelCatalin Marinas
Kernels compiled to ARM do not need to handle Thumb-2 module relocations as interworking is not allowed. This patch #ifdef's out the handling of such relocations. Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2010-08-05ARM: 6190/1: Remove dummy loads from the original relocation addressCatalin Marinas
Reading back the upper and lower values in the R_ARM_THM_CALL and R_ARM_THM_JUMP24 case was introduced by a previous commit but they are not needed. Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2010-08-05ARM: 6189/1: Add support for the MOVW/MOVT relocations in Thumb-2Catalin Marinas
The patch adds handling case for the R_ARM_THM_MOVW_ABS_NC and R_ARM_THM_MOVT_ABS relocations in arch/arm/kernel/module.c. Such relocations may appear in Thumb-2 compiled kernel modules. Reported-by: Kyungmin Park <kmpark@infradead.org> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2010-03-30include cleanup: Update gfp.h and slab.h includes to prepare for breaking ↵Tejun Heo
implicit slab.h inclusion from percpu.h percpu.h is included by sched.h and module.h and thus ends up being included when building most .c files. percpu.h includes slab.h which in turn includes gfp.h making everything defined by the two files universally available and complicating inclusion dependencies. percpu.h -> slab.h dependency is about to be removed. Prepare for this change by updating users of gfp and slab facilities include those headers directly instead of assuming availability. As this conversion needs to touch large number of source files, the following script is used as the basis of conversion. http://userweb.kernel.org/~tj/misc/slabh-sweep.py The script does the followings. * Scan files for gfp and slab usages and update includes such that only the necessary includes are there. ie. if only gfp is used, gfp.h, if slab is used, slab.h. * When the script inserts a new include, it looks at the include blocks and try to put the new include such that its order conforms to its surrounding. It's put in the include block which contains core kernel includes, in the same order that the rest are ordered - alphabetical, Christmas tree, rev-Xmas-tree or at the end if there doesn't seem to be any matching order. * If the script can't find a place to put a new include (mostly because the file doesn't have fitting include block), it prints out an error message indicating which .h file needs to be added to the file. The conversion was done in the following steps. 1. The initial automatic conversion of all .c files updated slightly over 4000 files, deleting around 700 includes and adding ~480 gfp.h and ~3000 slab.h inclusions. The script emitted errors for ~400 files. 2. Each error was manually checked. Some didn't need the inclusion, some needed manual addition while adding it to implementation .h or embedding .c file was more appropriate for others. This step added inclusions to around 150 files. 3. The script was run again and the output was compared to the edits from #2 to make sure no file was left behind. 4. Several build tests were done and a couple of problems were fixed. e.g. lib/decompress_*.c used malloc/free() wrappers around slab APIs requiring slab.h to be added manually. 5. The script was run on all .h files but without automatically editing them as sprinkling gfp.h and slab.h inclusions around .h files could easily lead to inclusion dependency hell. Most gfp.h inclusion directives were ignored as stuff from gfp.h was usually wildly available and often used in preprocessor macros. Each slab.h inclusion directive was examined and added manually as necessary. 6. percpu.h was updated not to include slab.h. 7. Build test were done on the following configurations and failures were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my distributed build env didn't work with gcov compiles) and a few more options had to be turned off depending on archs to make things build (like ipr on powerpc/64 which failed due to missing writeq). * x86 and x86_64 UP and SMP allmodconfig and a custom test config. * powerpc and powerpc64 SMP allmodconfig * sparc and sparc64 SMP allmodconfig * ia64 SMP allmodconfig * s390 SMP allmodconfig * alpha SMP allmodconfig * um on x86_64 SMP allmodconfig 8. percpu.h modifications were reverted so that it could be applied as a separate patch and serve as bisection point. Given the fact that I had only a couple of failures from tests on step 6, I'm fairly confident about the coverage of this conversion patch. If there is a breakage, it's likely to be something in one of the arch headers which should be easily discoverable easily on most builds of the specific arch. Signed-off-by: Tejun Heo <tj@kernel.org> Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
2009-07-24Thumb-2: Add support for loadable modulesCatalin Marinas
Modules compiled to Thumb-2 have two additional relocations needing to be resolved at load time, R_ARM_THM_CALL and R_ARM_THM_JUMP24, for BL and B.W instructions. The maximum Thumb-2 addressing range is +/-2^24 (+/-16MB) therefore the MODULES_VADDR macro in asm/memory.h is set to (MODULES_END - 8MB) for the Thumb-2 compiled kernel. Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2009-05-07[ARM] 5507/1: support R_ARM_MOVW_ABS_NC and MOVT_ABS relocation typesPaul Gortmaker
From: Bruce Ashfield <bruce.ashfield@windriver.com> To fully support the armv7-a instruction set/optimizations, support for the R_ARM_MOVW_ABS_NC and R_ARM_MOVT_ABS relocation types is required. The MOVW and MOVT are both load-immediate instructions, MOVW loads 16 bits into the bottom half of a register, and MOVT loads 16 bits into the top half of a register. The relocation information for these instructions has a full 32 bit value, plus an addend which is stored in the 16 immediate bits in the instruction itself. The immediate bits in the instruction are not contiguous (the register # splits it into a 4 bit and 12 bit value), so the addend has to be extracted accordingly and added to the value. The value is then split and put into the instruction; a MOVW uses the bottom 16 bits of the value, and a MOVT uses the top 16 bits. Signed-off-by: David Borman <david.borman@windriver.com> Signed-off-by: Bruce Ashfield <bruce.ashfield@windriver.com> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2009-03-28Merge branch 'master' into develRussell King
Conflicts: arch/arm/include/asm/elf.h arch/arm/kernel/module.c
2009-03-21[ARM] 5428/1: Module relocation update for R_ARM_V4BXDaniel Silverstone
It would seem when building kernel modules with modern binutils (required by modern GCC) for ARM v4T targets (specifically observed with the Samsung 24xx SoC which is an 920T) R_ARM_V4BX relocations are emitted for function epilogues. This manifests at module load time with an "unknown relocation: 40" error message. The following patch adds the R_ARM_V4BX relocation to the ARM kernel module loader. The relocation operation is taken from that within the binutils bfd library. Signed-off-by: Simtec Linux Team <linux@simtec.co.uk> Signed-off-by: Vincent Sanders <vince@simtec.co.uk> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2009-02-19[ARM] 5384/1: unwind: Add stack unwinding support for loadable modulesCatalin Marinas
This patch adds ELF section parsing for the unwinding tables in loadable modules together with the PREL31 relocation symbol resolving. Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2008-12-01[ARM] use asm/sections.hRussell King
Update to use the asm/sections.h header rather than declaring these symbols ourselves. Change __data_start to _data to conform with the naming found within asm/sections.h. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2008-11-06[ARM] fix naming of MODULE_START / MODULE_ENDRussell King
As of 73bdf0a60e607f4b8ecc5aec597105976565a84f, the kernel needs to know where modules are located in the virtual address space. On ARM, we located this region between MODULE_START and MODULE_END. Unfortunately, everyone else calls it MODULES_VADDR and MODULES_END. Update ARM to use the same naming, so is_vmalloc_or_module_addr() can work properly. Also update the comment on mm/vmalloc.c to reflect that ARM also places modules in a separate region from the vmalloc space. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2008-10-01[ARM] Improve non-executable supportRussell King
Add support for detecting non-executable stack binaries, and adjust permissions to prevent execution from data and stack areas. Also, ensure that READ_IMPLIES_EXEC is enabled for older CPUs where that is true, and for any executable-stack binary. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2008-07-24PAGE_ALIGN(): correctly handle 64-bit values on 32-bit architecturesAndrea Righi
On 32-bit architectures PAGE_ALIGN() truncates 64-bit values to the 32-bit boundary. For example: u64 val = PAGE_ALIGN(size); always returns a value < 4GB even if size is greater than 4GB. The problem resides in PAGE_MASK definition (from include/asm-x86/page.h for example): #define PAGE_SHIFT 12 #define PAGE_SIZE (_AC(1,UL) << PAGE_SHIFT) #define PAGE_MASK (~(PAGE_SIZE-1)) ... #define PAGE_ALIGN(addr) (((addr)+PAGE_SIZE-1)&PAGE_MASK) The "~" is performed on a 32-bit value, so everything in "and" with PAGE_MASK greater than 4GB will be truncated to the 32-bit boundary. Using the ALIGN() macro seems to be the right way, because it uses typeof(addr) for the mask. Also move the PAGE_ALIGN() definitions out of include/asm-*/page.h in include/linux/mm.h. See also lkml discussion: http://lkml.org/lkml/2008/6/11/237 [akpm@linux-foundation.org: fix drivers/media/video/uvc/uvc_queue.c] [akpm@linux-foundation.org: fix v850] [akpm@linux-foundation.org: fix powerpc] [akpm@linux-foundation.org: fix arm] [akpm@linux-foundation.org: fix mips] [akpm@linux-foundation.org: fix drivers/media/video/pvrusb2/pvrusb2-dvb.c] [akpm@linux-foundation.org: fix drivers/mtd/maps/uclinux.c] [akpm@linux-foundation.org: fix powerpc] Signed-off-by: Andrea Righi <righi.andrea@gmail.com> Cc: <linux-arch@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-08[ARM] Fix ARM branch relocation rangeKevin Welton
Branches in the ARM architecture are restricted to a range of +/- 32MB. However, the code in .../arch/arm/kernel/module.c::apply_relocate() was checking offset against a range of +/- 64MB. Signed-off-by: Kevin Welton <Kevin.Welton@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2006-09-27[ARM] nommu: allows to support module in nommuHyok S. Choi
A simple patch to support module in nommu mode. The vmalloc is used instead of __vmalloc_area which depends on CONFIG_MMU. Signed-off-by: Hyok S. Choi <hyok.choi@samsung.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2006-06-30Remove obsolete #include <linux/config.h>Jörn Engel
Signed-off-by: Jörn Engel <joern@wohnheim.fh-wedel.de> Signed-off-by: Adrian Bunk <bunk@stusta.de>
2005-12-14[ARM] 3205/1: Handle new EABI relocations when loading kernel modules.Daniel Jacobowitz
Patch from Daniel Jacobowitz Handle new EABI relocations when loading kernel modules. This is necessary for CONFIG_AEABI kernels, and also for some broken (since fixed) old ABI toolchains. Signed-off-by: Daniel Jacobowitz <dan@codesourcery.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2005-10-28[ARM] Fix sparse warningsRussell King
Fix sparse warnings in arch/arm/kernel/module.c, arch/arm/mm/consistent.c, drivers/pcmcia/sa1111_generic.c, and platform support files. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2005-03-13[PATCH] vmalloc: use __vmalloc_area in arch/armOleg Nesterov
Replace open coded __vmalloc() with __vmalloc_area(). Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru> Cc: Russell King <rmk@arm.linux.org.uk> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2004-11-10[ARM PATCH] 2160/1: allow modules to work with XIP kernelNicolas Pitre
Patch from Nicolas Pitre This should be applied on top of patch #2154/1. This maps the XIP kernel in the same virtual area as used for kernel modules instead of the previous arbitrary location. Doing so has the advantage of having a well defined kernel address not conflicting with the different definitions for VMALLOC_END, as well as making modules loadable without any indirect long branch calls. The work on XIPable MTD also requires this with code marked __xipram for the same reason. This of course reduces the space available for kernel modules from 16MB to either 14MB or 12MB depending on the size of the resulting kernel but that shouldn't be a real issue at all, given that the whole purpose behind XIP is to execute as much stuff from flash, which is better achieved by compiling drivers in the kernel directly. Signed-off-by: Nicolas Pitre Signed-off-by: Russell King
2004-01-04[ARM] Report more detail when unable to resolve module relocations.Russell King
2003-05-12[PATCH] implement module_arch_cleanup() in all architecturesAndrew Morton
From: Rusty Russell <rusty@rustcorp.com.au>, David Mosberger The patch below updates the other platforms with module_arch_cleanup(). Also, I added more debug output to kernel/module.c since I found it useful to be able to see the final section layout.
2003-01-12[MODULES] Centralize undefined symbol checks; handle undef weak.Richard Henderson
2003-01-05[PATCH] "constfrobbing considered harmful"Rusty Russell
The declaration of `module_frob_arch_sections' in moduleloader.h (and the definitions in most of the module.c files) are inconsistent with the definition in the PPC's module.c -- in the latter the first two arguments are not declared `const', whereas everyplace else they are. PS. secstrings can be modded to: if an arch can't handle discarding init, it simply renames the .init sections.
2003-01-01[PATCH] Modules 3/3: Sort sectionsRusty Russell
RTH's final complaint (so far 8) was that we should sort the module sections: archs might require some sections to be adjacent, so they can all be reached by a relative pointer (ie. GOT pointer). This implements that reordering, and simplfies the module interface for architectures as well. Previously an arch could specify it wanted extra space, but not where that space would be. The new method (used only by PPC so far) is to allocate an empty section (in asm/module.h or by setting LDFLAGS_MODULE to use an arch specific linker script), and expand that to the desired size in "module_frob_arch_sections()".
2003-01-01[PATCH] Modules 2/3: Use sh_addr instead of sh_offsetRusty Russell
From: Richard Henderson <rth@twiddle.net> Richard points out that we should be using sh_addr to hold the address, The original patch used to overload sh_offset to a pointer to the location of the section. This uses sh_addr, which is more correct and less surprising.
2002-11-21[ARM] Fix ARM module supportRussell King
This cset allows ARM modules to work again. The solution was suggested by Andi Kleen. We shrink the available user space size by 16MB, thereby opening up a window in virtual memory space between user space and the kernel direct mapped RAM. We place modules into this space, and, since the kernel image is always at the bottom of kernel direct mapped RAM, we can be assured that any 24-bit PC relocations (which have a range of +/- 32MB) will always be able to reach the kernel.
2002-11-19[ARM] 2.5.48 module fixups (and disable module loading for ARM)Russell King
This cset implements half the changes required for Rusty's in-kernel module loader. It implements the basic principles required to link a module with other modules and the kernel, as well as providing the required functions to allow the kernel to build with CONFIG_MODULES=y. However, as an unfortunate side effect, this cset DISABLES the ability to load modules on ARM; it's currently broken since we need to allocate a jump table for out of range branches (which is required for most calls from modules to the kernel binary to work.) Since we don't know the size of the jump table until we come to link the module, a subsequent vmalloc could return memory no where near the module itself, giving the same problem.