- 21 6月, 2016 2 次提交
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由 Jack Miller 提交于
This enables new registers, LMRR and LMSER, that can trigger an EBB in userspace code when a monitored load (via the new ldmx instruction) loads memory from a monitored space. This facility is controlled by a new FSCR bit, LM. This patch disables the FSCR LM control bit on task init and enables that bit when a load monitor facility unavailable exception is taken for using it. On context switch, this bit is then used to determine whether the two relevant registers are saved and restored. This is done lazily for performance reasons. Signed-off-by: NJack Miller <jack@codezen.org> Signed-off-by: NMichael Neuling <mikey@neuling.org> Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
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由 Michael Neuling 提交于
This fixes a few issues with FSCR init and switching. In commit 152d523e ("powerpc: Create context switch helpers save_sprs() and restore_sprs()") we moved the setting of the FSCR register from inside an CPU_FTR_ARCH_207S section to inside just a CPU_FTR_ARCH_DSCR section. Hence we are setting FSCR on POWER6/7 where the FSCR doesn't exist. This is harmless but we shouldn't do it. Also, we can simplify the FSCR context switch. We don't need to go through the calculation involving dscr_inherit. We can just restore what we saved last time. We also set an initial value in INIT_THREAD, so that pid 1 which is cloned from that gets a sane value. Based on patch by Jack Miller. Signed-off-by: NMichael Neuling <mikey@neuling.org> Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
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- 14 6月, 2016 2 次提交
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由 Michael Ellerman 提交于
Signed-off-by: NAndrea Gelmini <andrea.gelmini@gelma.net> Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
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由 Anton Blanchard 提交于
In both __giveup_fpu() and __giveup_altivec() we make two modifications to tsk->thread.regs->msr. gcc decides to do a read/modify/write of each change, so we end up with a load hit store: ld r9,264(r10) rldicl r9,r9,50,1 rotldi r9,r9,14 std r9,264(r10) ... ld r9,264(r10) rldicl r9,r9,40,1 rotldi r9,r9,24 std r9,264(r10) Fix this by using a temporary. Signed-off-by: NAnton Blanchard <anton@samba.org> Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
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- 21 5月, 2016 1 次提交
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由 Jiri Slaby 提交于
Define HAVE_EXIT_THREAD for archs which want to do something in exit_thread. For others, let's define exit_thread as an empty inline. This is a cleanup before we change the prototype of exit_thread to accept a task parameter. [akpm@linux-foundation.org: fix mips] Signed-off-by: NJiri Slaby <jslaby@suse.cz> Cc: "David S. Miller" <davem@davemloft.net> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: "James E.J. Bottomley" <jejb@parisc-linux.org> Cc: Aurelien Jacquiot <a-jacquiot@ti.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Chen Liqin <liqin.linux@gmail.com> Cc: Chris Metcalf <cmetcalf@mellanox.com> Cc: Chris Zankel <chris@zankel.net> Cc: David Howells <dhowells@redhat.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Guan Xuetao <gxt@mprc.pku.edu.cn> Cc: Haavard Skinnemoen <hskinnemoen@gmail.com> Cc: Hans-Christian Egtvedt <egtvedt@samfundet.no> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Helge Deller <deller@gmx.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru> Cc: James Hogan <james.hogan@imgtec.com> Cc: Jeff Dike <jdike@addtoit.com> Cc: Jesper Nilsson <jesper.nilsson@axis.com> Cc: Jiri Slaby <jslaby@suse.cz> Cc: Jonas Bonn <jonas@southpole.se> Cc: Koichi Yasutake <yasutake.koichi@jp.panasonic.com> Cc: Lennox Wu <lennox.wu@gmail.com> Cc: Ley Foon Tan <lftan@altera.com> Cc: Mark Salter <msalter@redhat.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Matt Turner <mattst88@gmail.com> Cc: Max Filippov <jcmvbkbc@gmail.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Simek <monstr@monstr.eu> Cc: Mikael Starvik <starvik@axis.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Rich Felker <dalias@libc.org> Cc: Richard Henderson <rth@twiddle.net> Cc: Richard Kuo <rkuo@codeaurora.org> Cc: Richard Weinberger <richard@nod.at> Cc: Russell King <linux@arm.linux.org.uk> Cc: Steven Miao <realmz6@gmail.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tony Luck <tony.luck@intel.com> Cc: Vineet Gupta <vgupta@synopsys.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 11 5月, 2016 1 次提交
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由 Aneesh Kumar K.V 提交于
We also use MMU_FTR_RADIX to branch out from code path specific to hash. No functionality change. Signed-off-by: NAneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
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- 14 4月, 2016 1 次提交
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由 Michael Ellerman 提交于
In order to support live patching we need to maintain an alternate stack of TOC & LR values. We use the base of the stack for this, and store the "live patch stack pointer" in struct thread_info. Unlike the other fields of thread_info, we can not statically initialise that value, so it must be done at run time. This patch just adds the code to support that, it is not enabled until the next patch which actually adds live patch support. Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au> Acked-by: NBalbir Singh <bsingharora@gmail.com>
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- 12 4月, 2016 1 次提交
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由 Daniel Axtens 提交于
Sometimes when sparse warns about undefined symbols, it isn't because they should have 'static' added, it's because they're overriding __weak symbols defined elsewhere, and the header has been missed. Fix a few of them by adding appropriate headers. Signed-off-by: NDaniel Axtens <dja@axtens.net> Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
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- 29 3月, 2016 1 次提交
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由 Oliver O'Halloran 提交于
In save_sprs() in process.c contains the following test: if (cpu_has_feature(cpu_has_feature(CPU_FTR_ALTIVEC))) t->vrsave = mfspr(SPRN_VRSAVE); CPU feature with the mask 0x1 is CPU_FTR_COHERENT_ICACHE so the test is equivilent to: if (cpu_has_feature(CPU_FTR_ALTIVEC) && cpu_has_feature(CPU_FTR_COHERENT_ICACHE)) On CPUs without support for both (i.e G5) this results in vrsave not being saved between context switches. The vector register save/restore code doesn't use VRSAVE to determine which registers to save/restore, but the value of VRSAVE is used to determine if altivec is being used in several code paths. Fixes: 152d523e ("powerpc: Create context switch helpers save_sprs() and restore_sprs()") Cc: stable@vger.kernel.org Signed-off-by: NOliver O'Halloran <oohall@gmail.com> Signed-off-by: NAnton Blanchard <anton@samba.org> Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
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- 02 3月, 2016 6 次提交
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由 Cyril Bur 提交于
This patch adds the ability to be able to save the VSX registers to the thread struct without giving up (disabling the facility) next time the process returns to userspace. This patch builds on a previous optimisation for the FPU and VEC registers in the thread copy path to avoid a possibly pointless reload of VSX state. Signed-off-by: NCyril Bur <cyrilbur@gmail.com> Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
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由 Cyril Bur 提交于
This patch adds the ability to be able to save the VEC registers to the thread struct without giving up (disabling the facility) next time the process returns to userspace. This patch builds on a previous optimisation for the FPU registers in the thread copy path to avoid a possibly pointless reload of VEC state. Signed-off-by: NCyril Bur <cyrilbur@gmail.com> Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
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由 Cyril Bur 提交于
This patch adds the ability to be able to save the FPU registers to the thread struct without giving up (disabling the facility) next time the process returns to userspace. This patch optimises the thread copy path (as a result of a fork() or clone()) so that the parent thread can return to userspace with hot registers avoiding a possibly pointless reload of FPU register state. Signed-off-by: NCyril Bur <cyrilbur@gmail.com> Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
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由 Cyril Bur 提交于
This prepares for the decoupling of saving {fpu,altivec,vsx} registers and marking {fpu,altivec,vsx} as being unused by a thread. Currently giveup_{fpu,altivec,vsx}() does both however optimisations to task switching can be made if these two operations are decoupled. save_all() will permit the saving of registers to thread structs and leave threads MSR with bits enabled. This patch introduces no functional change. Signed-off-by: NCyril Bur <cyrilbur@gmail.com> Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
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由 Cyril Bur 提交于
Currently the FPU, VEC and VSX facilities are lazily loaded. This is not a problem unless a process is using these facilities. Modern versions of GCC are very good at automatically vectorising code, new and modernised workloads make use of floating point and vector facilities, even the kernel makes use of vectorised memcpy. All this combined greatly increases the cost of a syscall since the kernel uses the facilities sometimes even in syscall fast-path making it increasingly common for a thread to take an *_unavailable exception soon after a syscall, not to mention potentially taking all three. The obvious overcompensation to this problem is to simply always load all the facilities on every exit to userspace. Loading up all FPU, VEC and VSX registers every time can be expensive and if a workload does avoid using them, it should not be forced to incur this penalty. An 8bit counter is used to detect if the registers have been used in the past and the registers are always loaded until the value wraps to back to zero. Several versions of the assembly in entry_64.S were tested: 1. Always calling C. 2. Performing a common case check and then calling C. 3. A complex check in asm. After some benchmarking it was determined that avoiding C in the common case is a performance benefit (option 2). The full check in asm (option 3) greatly complicated that codepath for a negligible performance gain and the trade-off was deemed not worth it. Signed-off-by: NCyril Bur <cyrilbur@gmail.com> [mpe: Move load_vec in the struct to fill an existing hole, reword change log] Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au> fixup
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由 Cyril Bur 提交于
Currently when threads get scheduled off they always giveup the FPU, Altivec (VMX) and Vector (VSX) units if they were using them. When they are scheduled back on a fault is then taken to enable each facility and load registers. As a result explicitly disabling FPU/VMX/VSX has not been necessary. Future changes and optimisations remove this mandatory giveup and fault which could cause calls such as clone() and fork() to copy threads and run them later with FPU/VMX/VSX enabled but no registers loaded. This patch starts the process of having MSR_{FP,VEC,VSX} mean that a threads registers are hot while not having MSR_{FP,VEC,VSX} means that the registers must be loaded. This allows for a smarter return to userspace. Signed-off-by: NCyril Bur <cyrilbur@gmail.com> Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
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- 28 2月, 2016 1 次提交
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由 Daniel Cashman 提交于
Replace calls to get_random_int() followed by a cast to (unsigned long) with calls to get_random_long(). Also address shifting bug which, in case of x86 removed entropy mask for mmap_rnd_bits values > 31 bits. Signed-off-by: NDaniel Cashman <dcashman@android.com> Acked-by: NKees Cook <keescook@chromium.org> Cc: "Theodore Ts'o" <tytso@mit.edu> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: David S. Miller <davem@davemloft.net> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Nick Kralevich <nnk@google.com> Cc: Jeff Vander Stoep <jeffv@google.com> Cc: Mark Salyzyn <salyzyn@android.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 14 12月, 2015 1 次提交
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由 Michael Neuling 提交于
Print MSR TM bits in oops messages. This appends them to the end like this: MSR: 8000000502823031 <SF,VEC,VSX,FP,ME,IR,DR,LE,TM[TE]> You get the TM[] only if at least one TM MSR bit is set. Inside the TM[], E means Enabled (bit 32), S means Suspended (bit 33), and T means Transactional (bit 34) If no bits are set, you get no TM[] output. Include rework of printbits() to handle this case. Signed-off-by: NMichael Neuling <mikey@neuling.org> Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
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- 10 12月, 2015 3 次提交
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由 Anton Blanchard 提交于
Two DSCR tests have a hack in them: /* * XXX: Force a context switch out so that DSCR * current value is copied into the thread struct * which is required for the child to inherit the * changed value. */ sleep(1); We should not be working around this in the testcase, it is a kernel bug. Fix it by copying the current DSCR to the child, instead of what we had in the thread struct at last context switch. Signed-off-by: NAnton Blanchard <anton@samba.org> Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
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由 Anton Blanchard 提交于
commit 152d523e ("powerpc: Create context switch helpers save_sprs() and restore_sprs()") moved the restore of SPRs after the call to _switch(). There is an issue with this approach - new tasks do not return through _switch(), they are set up by copy_thread() to directly return through ret_from_fork() or ret_from_kernel_thread(). This means restore_sprs() is not getting called for new tasks. Fix this by moving restore_sprs() before _switch(). Fixes: 152d523e ("powerpc: Create context switch helpers save_sprs() and restore_sprs()") Signed-off-by: NAnton Blanchard <anton@samba.org> Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
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由 Anton Blanchard 提交于
Commit a0e72cf1 ("powerpc: Create msr_check_and_{set,clear}()") removed a call to check_if_tm_restore_required() in the enable_kernel_*() functions. Add them back in. Fixes: a0e72cf1 ("powerpc: Create msr_check_and_{set,clear}()") Reported-by: NRashmica Gupta <rashmicy@gmail.com> Signed-off-by: NAnton Blanchard <anton@samba.org> Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
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- 02 12月, 2015 4 次提交
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由 Anton Blanchard 提交于
Remove a bunch of unnecessary fallback functions and group things in a more logical way. Signed-off-by: NAnton Blanchard <anton@samba.org> Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
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由 Anton Blanchard 提交于
Most of __switch_to() is housekeeping, TLB batching, timekeeping etc. Move these away from the more complex and critical context switching code. Signed-off-by: NAnton Blanchard <anton@samba.org> Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
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由 Anton Blanchard 提交于
Create a single function that flushes everything (FP, VMX, VSX, SPE). Doing this all at once means we only do one MSR write. Signed-off-by: NAnton Blanchard <anton@samba.org> Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
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由 Anton Blanchard 提交于
Create a single function that gives everything up (FP, VMX, VSX, SPE). Doing this all at once means we only do one MSR write. A context switch microbenchmark using yield(): http://ozlabs.org/~anton/junkcode/context_switch2.c ./context_switch2 --test=yield --fp --altivec --vector 0 0 shows an improvement of 3% on POWER8. Signed-off-by: NAnton Blanchard <anton@samba.org> [mpe: giveup_all() needs to be EXPORT_SYMBOL'ed] Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
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- 01 12月, 2015 9 次提交
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由 Anton Blanchard 提交于
More consolidation of our MSR available bit handling. Signed-off-by: NAnton Blanchard <anton@samba.org> Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
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由 Anton Blanchard 提交于
Add a boot option that strictly manages the MSR unavailable bits. This catches kernel uses of FP/Altivec/SPE that would otherwise corrupt user state. Signed-off-by: NAnton Blanchard <anton@samba.org> Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
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由 Anton Blanchard 提交于
Create helper functions to set and clear MSR bits after first checking if they are already set. Grouping them will make it easy to avoid the MSR writes in a subsequent optimisation. Signed-off-by: NAnton Blanchard <anton@samba.org> Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
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由 Anton Blanchard 提交于
Move the MSR modification into c. Removing it from the assembly function will allow us to avoid costly MSR writes by batching them up. Check the FP and VMX bits before calling the relevant giveup_*() function. This makes giveup_vsx() and flush_vsx_to_thread() perform more like their sister functions, and allows us to use flush_vsx_to_thread() in the signal code. Move the check_if_tm_restore_required() check in. Signed-off-by: NAnton Blanchard <anton@samba.org> Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
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由 Anton Blanchard 提交于
Move the MSR modification into new c functions. Removing it from the low level functions will allow us to avoid costly MSR writes by batching them up. Move the check_if_tm_restore_required() check into these new functions. Signed-off-by: NAnton Blanchard <anton@samba.org> Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
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由 Anton Blanchard 提交于
mtmsrd_isync() will do an mtmsrd followed by an isync on older processors. On newer processors we avoid the isync via a feature fixup. Signed-off-by: NAnton Blanchard <anton@samba.org> Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
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由 Anton Blanchard 提交于
Instead of having multiple giveup_*_maybe_transactional() functions, separate out the TM check into a new function called check_if_tm_restore_required(). This will make it easier to optimise the giveup_*() functions in a subsequent patch. Signed-off-by: NAnton Blanchard <anton@samba.org> Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
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由 Anton Blanchard 提交于
The UP only lazy floating point and vector optimisations were written back when SMP was not common, and neither glibc nor gcc used vector instructions. Now SMP is very common, glibc aggressively uses vector instructions and gcc autovectorises. We want to add new optimisations that apply to both UP and SMP, but in preparation for that remove these UP only optimisations. Signed-off-by: NAnton Blanchard <anton@samba.org> Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
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由 Anton Blanchard 提交于
Move all our context switch SPR save and restore code into two helpers. We do a few optimisations: - Group all mfsprs and all mtsprs. In many cases an mtspr sets a scoreboarding bit that an mfspr waits on, so the current practise of mfspr A; mtspr A; mfpsr B; mtspr B is the worst scheduling we can do. - SPR writes are slow, so check that the value is changing before writing it. A context switch microbenchmark using yield(): http://ozlabs.org/~anton/junkcode/context_switch2.c ./context_switch2 --test=yield 0 0 shows an improvement of almost 10% on POWER8. Signed-off-by: NAnton Blanchard <anton@samba.org> Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
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- 23 11月, 2015 1 次提交
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由 Michael Neuling 提交于
Currently we can hit a scenario where we'll tm_reclaim() twice. This results in a TM bad thing exception because the second reclaim occurs when not in suspend mode. The scenario in which this can happen is the following. We attempt to deliver a signal to userspace. To do this we need obtain the stack pointer to write the signal context. To get this stack pointer we must tm_reclaim() in case we need to use the checkpointed stack pointer (see get_tm_stackpointer()). Normally we'd then return directly to userspace to deliver the signal without going through __switch_to(). Unfortunatley, if at this point we get an error (such as a bad userspace stack pointer), we need to exit the process. The exit will result in a __switch_to(). __switch_to() will attempt to save the process state which results in another tm_reclaim(). This tm_reclaim() now causes a TM Bad Thing exception as this state has already been saved and the processor is no longer in TM suspend mode. Whee! This patch checks the state of the MSR to ensure we are TM suspended before we attempt the tm_reclaim(). If we've already saved the state away, we should no longer be in TM suspend mode. This has the additional advantage of checking for a potential TM Bad Thing exception. Found using syscall fuzzer. Fixes: fb09692e ("powerpc: Add reclaim and recheckpoint functions for context switching transactional memory processes") Cc: stable@vger.kernel.org # v3.9+ Signed-off-by: NMichael Neuling <mikey@neuling.org> Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
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- 16 7月, 2015 1 次提交
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由 Anshuman Khandual 提交于
Currently tm_orig_msr is getting used during process context switch only. Then there is ckpt_regs which saves the checkpointed userspace context The MSR slot contained in ckpt_regs structure can be used during process context switch instead of tm_orig_msr, thus allowing us to drop it from thread_struct structure. This patch does that change. Acked-by: NMichael Neuling <mikey@neuling.org> Signed-off-by: NAnshuman Khandual <khandual@linux.vnet.ibm.com> Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
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- 14 7月, 2015 1 次提交
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enable_kernel_vsx() function was commented since anything was using it. However, vmx-crypto driver uses VSX instructions which are only available if VSX is enable. Otherwise it rises an exception oops. This patch uncomment enable_kernel_vsx() routine and makes it available. Signed-off-by: NLeonidas S. Barbosa <leosilva@linux.vnet.ibm.com> Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>
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- 07 6月, 2015 1 次提交
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由 Anshuman Khandual 提交于
The process context switch code no longer uses dscr_default variable from the sysfs.c file. The variable became unused when we started storing the CPU specific DSCR value in the PACA structure instead. This patch just removes this extern declaration. It was originally added by the following commit. Signed-off-by: NAnshuman Khandual <khandual@linux.vnet.ibm.com> Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
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- 20 3月, 2015 1 次提交
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由 Alex Dowad 提交于
The 'arg' argument to copy_thread() is only ever used when forking a new kernel thread. Hence, rename it to 'kthread_arg' for clarity. Signed-off-by: NAlex Dowad <alexinbeijing@gmail.com> Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
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- 17 11月, 2014 1 次提交
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由 Vineeth Vijayan 提交于
Back in 2009 we merged 501cb16d "Randomise PIEs", which added support for randomizing PIE (Position Independent Executable) binaries. That commit added randomize_et_dyn(), which correctly randomized the addresses, but failed to honor PF_RANDOMIZE. That means it was not possible to disable PIE randomization via the personality flag, or /proc/sys/kernel/randomize_va_space. Since then there has been generic support for PIE randomization added to binfmt_elf.c, selectable via ARCH_BINFMT_ELF_RANDOMIZE_PIE. Enabling that allows us to drop randomize_et_dyn(), which means we start honoring PF_RANDOMIZE correctly. It also causes a fairly major change to how we layout PIE binaries. Currently we will place the binary at 512MB-520MB for 32 bit binaries, or 512MB-1.5GB for 64 bit binaries, eg: $ cat /proc/$$/maps 4e550000-4e580000 r-xp 00000000 08:02 129813 /bin/dash 4e580000-4e590000 rw-p 00020000 08:02 129813 /bin/dash 10014110000-10014140000 rw-p 00000000 00:00 0 [heap] 3fffaa3f0000-3fffaa5a0000 r-xp 00000000 08:02 921 /lib/powerpc64le-linux-gnu/libc-2.19.so 3fffaa5a0000-3fffaa5b0000 rw-p 001a0000 08:02 921 /lib/powerpc64le-linux-gnu/libc-2.19.so 3fffaa5c0000-3fffaa5d0000 rw-p 00000000 00:00 0 3fffaa5d0000-3fffaa5f0000 r-xp 00000000 00:00 0 [vdso] 3fffaa5f0000-3fffaa620000 r-xp 00000000 08:02 1246 /lib/powerpc64le-linux-gnu/ld-2.19.so 3fffaa620000-3fffaa630000 rw-p 00020000 08:02 1246 /lib/powerpc64le-linux-gnu/ld-2.19.so 3ffffc340000-3ffffc370000 rw-p 00000000 00:00 0 [stack] With this commit applied we don't do any special randomisation for the binary, and instead rely on mmap randomisation. This means the binary ends up at high addresses, eg: $ cat /proc/$$/maps 3fff99820000-3fff999d0000 r-xp 00000000 08:02 921 /lib/powerpc64le-linux-gnu/libc-2.19.so 3fff999d0000-3fff999e0000 rw-p 001a0000 08:02 921 /lib/powerpc64le-linux-gnu/libc-2.19.so 3fff999f0000-3fff99a00000 rw-p 00000000 00:00 0 3fff99a00000-3fff99a20000 r-xp 00000000 00:00 0 [vdso] 3fff99a20000-3fff99a50000 r-xp 00000000 08:02 1246 /lib/powerpc64le-linux-gnu/ld-2.19.so 3fff99a50000-3fff99a60000 rw-p 00020000 08:02 1246 /lib/powerpc64le-linux-gnu/ld-2.19.so 3fff99a60000-3fff99a90000 r-xp 00000000 08:02 129813 /bin/dash 3fff99a90000-3fff99aa0000 rw-p 00020000 08:02 129813 /bin/dash 3fffc3de0000-3fffc3e10000 rw-p 00000000 00:00 0 [stack] 3fffc55e0000-3fffc5610000 rw-p 00000000 00:00 0 [heap] Although this should be OK, it's possible it might break badly written binaries that make assumptions about the address space layout. Signed-off-by: NVineeth Vijayan <vvijayan@mvista.com> [mpe: Rewrite changelog] Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
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- 10 11月, 2014 1 次提交
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由 Anton Blanchard 提交于
mod_return_to_handler is the same as return_to_handler, except it handles the change of the TOC (r2). Add this into return_to_handler and remove mod_return_to_handler. Signed-off-by: NAnton Blanchard <anton@samba.org> Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
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