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2017-11-15MIPS: AR7: Ensure that serial ports are properly set upOswald Buddenhagen
commit b084116f8587b222a2c5ef6dcd846f40f24b9420 upstream. Without UPF_FIXED_TYPE, the data from the PORT_AR7 uart_config entry is never copied, resulting in a dead port. Fixes: 154615d55459 ("MIPS: AR7: Use correct UART port type") Signed-off-by: Oswald Buddenhagen <oswald.buddenhagen@gmx.de> [jonas.gorski: add Fixes tag] Signed-off-by: Jonas Gorski <jonas.gorski@gmail.com> Reviewed-by: Florian Fainelli <f.fainelli@gmail.com> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Yoshihiro YUNOMAE <yoshihiro.yunomae.ez@hitachi.com> Cc: Nicolas Schichan <nschichan@freebox.fr> Cc: Oswald Buddenhagen <oswald.buddenhagen@gmx.de> Cc: linux-mips@linux-mips.org Cc: linux-serial@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/17543/ Signed-off-by: James Hogan <jhogan@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-15MIPS: AR7: Defer registration of GPIOJonas Gorski
commit e6b03ab63b4d270e0249f96536fde632409dc1dc upstream. When called from prom init code, ar7_gpio_init() will fail as it will call gpiochip_add() which relies on a working kmalloc() to alloc the gpio_desc array and kmalloc is not useable yet at prom init time. Move ar7_gpio_init() to ar7_register_devices() (a device_initcall) where kmalloc works. Fixes: 14e85c0e69d5 ("gpio: remove gpio_descs global array") Signed-off-by: Jonas Gorski <jonas.gorski@gmail.com> Reviewed-by: Florian Fainelli <f.fainelli@gmail.com> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Yoshihiro YUNOMAE <yoshihiro.yunomae.ez@hitachi.com> Cc: Nicolas Schichan <nschichan@freebox.fr> Cc: linux-mips@linux-mips.org Cc: linux-serial@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/17542/ Signed-off-by: James Hogan <jhogan@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-15MIPS: BMIPS: Fix missing cbr addressJaedon Shin
commit ea4b3afe1eac8f88bb453798a084fba47a1f155a upstream. Fix NULL pointer access in BMIPS3300 RAC flush. Fixes: 738a3f79027b ("MIPS: BMIPS: Add early CPU initialization code") Signed-off-by: Jaedon Shin <jaedon.shin@gmail.com> Reviewed-by: Florian Fainelli <f.fainelli@gmail.com> Cc: Kevin Cernekee <cernekee@gmail.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/16423/ Signed-off-by: James Hogan <jhogan@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-15MIPS: SMP: Fix deadlock & online raceMatt Redfearn
commit 9e8c399a88f0b87e41a894911475ed2a8f8dff9e upstream. Commit 6f542ebeaee0 ("MIPS: Fix race on setting and getting cpu_online_mask") effectively reverted commit 8f46cca1e6c06 ("MIPS: SMP: Fix possibility of deadlock when bringing CPUs online") and thus has reinstated the possibility of deadlock. The commit was based on testing of kernel v4.4, where the CPU hotplug core code issued a BUG() if the starting CPU is not marked online when the boot CPU returns from __cpu_up. The commit fixes this race (in v4.4), but re-introduces the deadlock situation. As noted in the commit message, upstream differs in this area. Commit 8df3e07e7f21f ("cpu/hotplug: Let upcoming cpu bring itself fully up") adds a completion event in the CPU hotplug core code, making this race impossible. However, people were unhappy with relying on the core code to do the right thing. To address the issues both commits were trying to fix, add a second completion event in the MIPS smp hotplug path. It removes the possibility of a race, since the MIPS smp hotplug code now synchronises both the boot and secondary CPUs before they return to the hotplug core code. It also addresses the deadlock by ensuring that the secondary CPU is not marked online before it's counters are synchronised. This fix should also be backported to fix the race condition introduced by the backport of commit 8f46cca1e6c06 ("MIPS: SMP: Fix possibility of deadlock when bringing CPUs online"), through really that race only existed before commit 8df3e07e7f21f ("cpu/hotplug: Let upcoming cpu bring itself fully up"). Signed-off-by: Matt Redfearn <matt.redfearn@imgtec.com> Fixes: 6f542ebeaee0 ("MIPS: Fix race on setting and getting cpu_online_mask") CC: Matija Glavinic Pecotic <matija.glavinic-pecotic.ext@nokia.com> Patchwork: https://patchwork.linux-mips.org/patch/17376/ Signed-off-by: James Hogan <jhogan@kernel.org> [jhogan@kernel.org: Backported 4.1..4.9] Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-15MIPS: Fix race on setting and getting cpu_online_maskMatija Glavinic Pecotic
commit 6f542ebeaee0ee552a902ce3892220fc22c7ec8e upstream. While testing cpu hoptlug (cpu down and up in loops) on kernel 4.4, it was observed that occasionally check for cpu online will fail in kernel/cpu.c, _cpu_up: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable.git/tree/kernel/cpu.c?h=v4.4.79#n485 518 /* Arch-specific enabling code. */ 519 ret = __cpu_up(cpu, idle); 520 521 if (ret != 0) 522 goto out_notify; 523 BUG_ON(!cpu_online(cpu)); Reason is race between start_secondary and _cpu_up. cpu_callin_map is set before cpu_online_mask. In __cpu_up, cpu_callin_map is waited for, but cpu online mask is not, resulting in race in which secondary processor started and set cpu_callin_map, but not yet set the online mask,resulting in above BUG being hit. Upstream differs in the area. cpu_online check is in bringup_wait_for_ap, which is after cpu reached AP_ONLINE_IDLE,where secondary passed its start function. Nonetheless, fix makes start_secondary safe and not depending on other locks throughout the code. It protects as well against cpu_online checks put in between sometimes in the future. Fix this by moving completion after all flags are set. Signed-off-by: Matija Glavinic Pecotic <matija.glavinic-pecotic.ext@nokia.com> Cc: Alexander Sverdlin <alexander.sverdlin@nokia.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/16925/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-15MIPS: SMP: Use a completion event to signal CPU upMatt Redfearn
commit a00eeede507c975087b7b8df8cf2c9f88ba285de upstream. If a secondary CPU failed to start, for any reason, the CPU requesting the secondary to start would get stuck in the loop waiting for the secondary to be present in the cpu_callin_map. Rather than that, use a completion event to signal that the secondary CPU has started and is waiting to synchronise counters. Since the CPU presence will no longer be marked in cpu_callin_map, remove the redundant test from arch_cpu_idle_dead(). Signed-off-by: Matt Redfearn <matt.redfearn@imgtec.com> Cc: Maciej W. Rozycki <macro@imgtec.com> Cc: Jiri Slaby <jslaby@suse.cz> Cc: Paul Gortmaker <paul.gortmaker@windriver.com> Cc: Chris Metcalf <cmetcalf@mellanox.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Qais Yousef <qsyousef@gmail.com> Cc: James Hogan <james.hogan@imgtec.com> Cc: Paul Burton <paul.burton@imgtec.com> Cc: Marcin Nowakowski <marcin.nowakowski@imgtec.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/14502/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-15MIPS: Fix CM region target definitionsPaul Burton
commit 6a6cba1d945a7511cdfaf338526871195e420762 upstream. The default CM target field in the GCR_BASE register is encoded with 0 meaning memory & 1 being reserved. However the definitions we use for those bits effectively get these two values backwards - likely because they were copied from the definitions for the CM regions where the target is encoded differently. This results in use setting up GCR_BASE with the reserved target value by default, rather than targeting memory as intended. Although we currently seem to get away with this it's not a great idea to rely upon. Fix this by changing our macros to match the documentated target values. The incorrect encoding became used as of commit 9f98f3dd0c51 ("MIPS: Add generic CM probe & access code") in the Linux v3.15 cycle, and was likely carried forwards from older but unused code introduced by commit 39b8d5254246 ("[MIPS] Add support for MIPS CMP platform.") in the v2.6.26 cycle. Fixes: 9f98f3dd0c51 ("MIPS: Add generic CM probe & access code") Signed-off-by: Paul Burton <paul.burton@mips.com> Reported-by: Matt Redfearn <matt.redfearn@mips.com> Reviewed-by: James Hogan <jhogan@kernel.org> Cc: Matt Redfearn <matt.redfearn@mips.com> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: linux-mips@linux-mips.org Cc: <stable@vger.kernel.org> # v3.15+ Patchwork: https://patchwork.linux-mips.org/patch/17562/ Signed-off-by: James Hogan <jhogan@kernel.org> [jhogan@kernel.org: Backported 3.15..4.13] Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-15MIPS: microMIPS: Fix incorrect mask in insn_table_MMGustavo A. R. Silva
commit 77238e76b9156d28d86c1e31c00ed2960df0e4de upstream. It seems that this is a typo error and the proper bit masking is "RT | RS" instead of "RS | RS". This issue was detected with the help of Coccinelle. Fixes: d6b3314b49e1 ("MIPS: uasm: Add lh uam instruction") Reported-by: Julia Lawall <julia.lawall@lip6.fr> Signed-off-by: Gustavo A. R. Silva <garsilva@embeddedor.com> Reviewed-by: James Hogan <jhogan@kernel.org> Patchwork: https://patchwork.linux-mips.org/patch/17551/ Signed-off-by: James Hogan <jhogan@kernel.org> [jhogan@kernel.org: Backported 3.16..4.12] Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-10-21MIPS: Fix minimum alignment requirement of IRQ stackMatt Redfearn
commit 5fdc66e046206306bf61ff2d626bfa52ca087f7b upstream. Commit db8466c581cc ("MIPS: IRQ Stack: Unwind IRQ stack onto task stack") erroneously set the initial stack pointer of the IRQ stack to a value with a 4 byte alignment. The MIPS32 ABI requires that the minimum stack alignment is 8 byte, and the MIPS64 ABIs(n32/n64) require 16 byte minimum alignment. Fix IRQ_STACK_START such that it leaves space for the dummy stack frame (containing interrupted task kernel stack pointer) while also meeting minimum alignment requirements. Fixes: db8466c581cc ("MIPS: IRQ Stack: Unwind IRQ stack onto task stack") Reported-by: Darius Ivanauskas <dasilt@yahoo.com> Signed-off-by: Matt Redfearn <matt.redfearn@imgtec.com> Cc: Chris Metcalf <cmetcalf@mellanox.com> Cc: Petr Mladek <pmladek@suse.com> Cc: Aaron Tomlin <atomlin@redhat.com> Cc: Jason A. Donenfeld <jason@zx2c4.com> Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/16760/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-10-18MIPS: math-emu: Remove pr_err() calls from fpu_emu()Paul Burton
commit ca8eb05b5f332a9e1ab3e2ece498d49f4d683470 upstream. The FPU emulator includes 2 calls to pr_err() which are triggered by invalid instruction encodings for MIPSr6 cmp.cond.fmt instructions. These cases are not kernel errors, merely invalid instructions which are already handled by delivering a SIGILL which will provide notification that something failed in cases where that makes sense. In cases where that SIGILL is somewhat expected & being handled, for example when crashme happens to generate one of the affected bad encodings, the message is printed with no useful context about what triggered it & spams the kernel log for no good reason. Remove the pr_err() calls to make crashme run silently & treat the bad encodings the same way we do others, with a SIGILL & no further kernel log output. Signed-off-by: Paul Burton <paul.burton@imgtec.com> Fixes: f8c3c6717a71 ("MIPS: math-emu: Add support for the CMP.condn.fmt R6 instruction") Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/17253/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-10-08MIPS: smp-cps: Fix retrieval of VPE mask on big endian CPUsMatt Redfearn
[ Upstream commit fb2155e3c30dc2043b52020e26965067a3e7779c ] The vpe_mask member of struct core_boot_config is of type atomic_t, which is a 32bit type. In cps-vec.S this member was being retrieved by a PTR_L macro, which on 64bit systems is a 64bit load. On little endian systems this is OK, since the double word that is retrieved will have the required less significant word in the correct position. However, on big endian systems the less significant word of the load is retrieved from address+4, and the more significant from address+0. The destination register therefore ends up with the required word in the more significant word e.g. when starting the second VP of a big endian 64bit system, the load PTR_L ta2, COREBOOTCFG_VPEMASK(a0) ends up setting register ta2 to 0x0000000300000000 When this value is written to the CPC it is ignored, since it is invalid to write anything larger than 4 bits. This results in any VP other than VP0 in a core failing to start in 64bit big endian systems. Change the load to a 32bit load word instruction to fix the bug. Fixes: f12401d7219f ("MIPS: smp-cps: Pull boot config retrieval out of mips_cps_boot_vpes") Signed-off-by: Matt Redfearn <matt.redfearn@imgtec.com> Cc: Paul Burton <paul.burton@imgtec.com> Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/15787/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Sasha Levin <alexander.levin@verizon.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-10-08MIPS: IRQ Stack: Unwind IRQ stack onto task stackMatt Redfearn
[ Upstream commit db8466c581cca1a08b505f1319c3ecd246f16fa8 ] When the separate IRQ stack was introduced, stack unwinding only proceeded as far as the top of the IRQ stack, leading to kernel backtraces being less useful, lacking the trace of what was interrupted. Fix this by providing a means for the kernel to unwind the IRQ stack onto the interrupted task stack. The processor state is saved to the kernel task stack on interrupt. The IRQ_STACK_START macro reserves an unsigned long at the top of the IRQ stack where the interrupted task stack pointer can be saved. After the active stack is switched to the IRQ stack, save the interrupted tasks stack pointer to the reserved location. Fix the stack unwinding code to look for the frame being the top of the IRQ stack and if so get the next frame from the saved location. The existing test does not work with the separate stack since the ra is no longer pointed at ret_from_{irq,exception}. The test to stop unwinding the stack 32 bytes from the top of a stack must be modified to allow unwinding to continue up to the location of the saved task stack pointer when on the IRQ stack. The low / high marks of the stack are set depending on whether the sp is on an irq stack or not. Signed-off-by: Matt Redfearn <matt.redfearn@imgtec.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Marcin Nowakowski <marcin.nowakowski@imgtec.com> Cc: Masanari Iida <standby24x7@gmail.com> Cc: Chris Metcalf <cmetcalf@mellanox.com> Cc: James Hogan <james.hogan@imgtec.com> Cc: Paul Burton <paul.burton@imgtec.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Jason A. Donenfeld <jason@zx2c4.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/15788/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Sasha Levin <alexander.levin@verizon.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-10-08mips: ath79: clock:- Unmap region obtained by of_iomapArvind Yadav
[ Upstream commit b3d91db3f71d5f70ea60d900425a3f96aeb3d065 ] Free memory mapping, if ath79_clocks_init_dt_ng is not successful. Signed-off-by: Arvind Yadav <arvind.yadav.cs@gmail.com> Fixes: 3bdf1071ba7d ("MIPS: ath79: update devicetree clock support for AR9132") Cc: antonynpavlov@gmail.com Cc: albeu@free.fr Cc: hackpascal@gmail.com Cc: sboyd@codeaurora.org Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/14915/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Sasha Levin <alexander.levin@verizon.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-10-08MIPS: Lantiq: Fix another request_mem_region() return code checkArnd Bergmann
[ Upstream commit 98ea51cb0c8ce009d9da1fd7b48f0ff1d7a9bbb0 ] Hauke already fixed a couple of them, but one instance remains that checks for a negative integer when it should check for a NULL pointer: arch/mips/lantiq/xway/sysctrl.c: In function 'ltq_soc_init': arch/mips/lantiq/xway/sysctrl.c:473:19: error: ordered comparison of pointer with integer zero [-Werror=extra] Fixes: 6e807852676a ("MIPS: Lantiq: Fix check for return value of request_mem_region()") Signed-off-by: Arnd Bergmann <arnd@arndb.de> Cc: John Crispin <john@phrozen.org> Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/15043/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Sasha Levin <alexander.levin@verizon.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-10-08MIPS: ralink: Fix incorrect assignment on ralink_socColin Ian King
[ Upstream commit 08d90c81b714482dceb5323d14f6617bcf55ee61 ] ralink_soc sould be assigned to RT3883_SOC, replace incorrect comparision with assignment. Signed-off-by: Colin Ian King <colin.king@canonical.com> Fixes: 418d29c87061 ("MIPS: ralink: Unify SoC id handling") Cc: John Crispin <john@phrozen.org> Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/14903/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Sasha Levin <alexander.levin@verizon.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-10-08MIPS: ralink: Fix a typo in the pinmux setup.John Crispin
[ Upstream commit 58181a117d353427127a2e7afc7cf1ab44759828 ] There is a typo inside the pinmux setup code. The function is really called utif and not util. This was recently discovered when people were trying to make the UTIF interface work. Signed-off-by: John Crispin <john@phrozen.org> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/14899/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Sasha Levin <alexander.levin@verizon.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-10-08MIPS: Ensure bss section ends on a long-aligned addressPaul Burton
[ Upstream commit 3f00f4d8f083bc61005d0a1ef592b149f5c88bbd ] When clearing the .bss section in kernel_entry we do so using LONG_S instructions, and branch whilst the current write address doesn't equal the end of the .bss section minus the size of a long integer. The .bss section always begins at a long-aligned address and we always increment the write pointer by the size of a long integer - we therefore rely upon the .bss section ending at a long-aligned address. If this is not the case then the long-aligned write address can never be equal to the non-long-aligned end address & we will continue to increment past the end of the .bss section, attempting to zero the rest of memory. Despite this requirement that .bss end at a long-aligned address we pass 0 as the end alignment requirement to the BSS_SECTION macro and thus don't guarantee any particular alignment, allowing us to hit the error condition described above. Fix this by instead passing 8 bytes as the end alignment argument to the BSS_SECTION macro, ensuring that the end of the .bss section is always at least long-aligned. Signed-off-by: Paul Burton <paul.burton@imgtec.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/14526/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Sasha Levin <alexander.levin@verizon.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-09-27MIPS: math-emu: <MADDF|MSUBF>.D: Fix accuracy (64-bit case)Douglas Leung
commit 2cfa58259f4b65b33ebe8f167019a1f89c6c3289 upstream. Implement fused multiply-add with correct accuracy. Fused multiply-add operation has better accuracy than respective sequential execution of multiply and add operations applied on the same inputs. This is because accuracy errors accumulate in latter case. This patch implements fused multiply-add with the same accuracy as it is implemented in hardware, using 128-bit intermediate calculations. One test case example (raw bits) that this patch fixes: MADDF.D fd,fs,ft: fd = 0x00000ca000000000 fs = ft = 0x3f40624dd2f1a9fc Fixes: e24c3bec3e8e ("MIPS: math-emu: Add support for the MIPS R6 MADDF FPU instruction") Fixes: 83d43305a1df ("MIPS: math-emu: Add support for the MIPS R6 MSUBF FPU instruction") Signed-off-by: Douglas Leung <douglas.leung@imgtec.com> Signed-off-by: Miodrag Dinic <miodrag.dinic@imgtec.com> Signed-off-by: Goran Ferenc <goran.ferenc@imgtec.com> Signed-off-by: Aleksandar Markovic <aleksandar.markovic@imgtec.com> Cc: Douglas Leung <douglas.leung@imgtec.com> Cc: Bo Hu <bohu@google.com> Cc: James Hogan <james.hogan@imgtec.com> Cc: Jin Qian <jinqian@google.com> Cc: Paul Burton <paul.burton@imgtec.com> Cc: Petar Jovanovic <petar.jovanovic@imgtec.com> Cc: Raghu Gandham <raghu.gandham@imgtec.com> Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/16891/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-09-27MIPS: math-emu: <MADDF|MSUBF>.S: Fix accuracy (32-bit case)Douglas Leung
commit b3b8e1eb27c523e32b6a8aa7ec8ac4754456af57 upstream. Implement fused multiply-add with correct accuracy. Fused multiply-add operation has better accuracy than respective sequential execution of multiply and add operations applied on the same inputs. This is because accuracy errors accumulate in latter case. This patch implements fused multiply-add with the same accuracy as it is implemented in hardware, using 64-bit intermediate calculations. One test case example (raw bits) that this patch fixes: MADDF.S fd,fs,ft: fd = 0x22575225 fs = ft = 0x3727c5ac Fixes: e24c3bec3e8e ("MIPS: math-emu: Add support for the MIPS R6 MADDF FPU instruction") Fixes: 83d43305a1df ("MIPS: math-emu: Add support for the MIPS R6 MSUBF FPU instruction") Signed-off-by: Douglas Leung <douglas.leung@imgtec.com> Signed-off-by: Miodrag Dinic <miodrag.dinic@imgtec.com> Signed-off-by: Goran Ferenc <goran.ferenc@imgtec.com> Signed-off-by: Aleksandar Markovic <aleksandar.markovic@imgtec.com> Cc: Douglas Leung <douglas.leung@imgtec.com> Cc: Bo Hu <bohu@google.com> Cc: James Hogan <james.hogan@imgtec.com> Cc: Jin Qian <jinqian@google.com> Cc: Paul Burton <paul.burton@imgtec.com> Cc: Petar Jovanovic <petar.jovanovic@imgtec.com> Cc: Raghu Gandham <raghu.gandham@imgtec.com> Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/16890/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-09-27MIPS: math-emu: <MADDF|MSUBF>.<D|S>: Clean up "maddf_flags" enumerationAleksandar Markovic
commit ae11c0619973ffd73a496308d8a1cb5e1a353737 upstream. Fix definition and usage of "maddf_flags" enumeration. Avoid duplicate definition and apply more common capitalization. This patch does not change any scenario. It just makes MADDF and MSUBF emulation code more readable and easier to maintain, and hopefully prevents future bugs as well. Signed-off-by: Miodrag Dinic <miodrag.dinic@imgtec.com> Signed-off-by: Goran Ferenc <goran.ferenc@imgtec.com> Signed-off-by: Aleksandar Markovic <aleksandar.markovic@imgtec.com> Reviewed-by: James Hogan <james.hogan@imgtec.com> Cc: Bo Hu <bohu@google.com> Cc: Douglas Leung <douglas.leung@imgtec.com> Cc: Jin Qian <jinqian@google.com> Cc: Paul Burton <paul.burton@imgtec.com> Cc: Petar Jovanovic <petar.jovanovic@imgtec.com> Cc: Raghu Gandham <raghu.gandham@imgtec.com> Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/16889/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-09-27MIPS: math-emu: <MADDF|MSUBF>.<D|S>: Fix some cases of zero inputsAleksandar Markovic
commit 7cf64ce4d37f1b4f44365fcf77f565d523819dcd upstream. Fix the cases of <MADDF|MSUBF>.<D|S> when any of two multiplicands is +0 or -0, and the third input is also +0 or -0. Depending on the signs of inputs, certain special cases must be handled. A relevant example: MADDF.S fd,fs,ft: If fs contains +0.0, ft contains -0.0, and fd contains 0.0, fd is going to contain +0.0 (without this patch, it used to contain -0.0). Fixes: e24c3bec3e8e ("MIPS: math-emu: Add support for the MIPS R6 MADDF FPU instruction") Fixes: 83d43305a1df ("MIPS: math-emu: Add support for the MIPS R6 MSUBF FPU instruction") Signed-off-by: Miodrag Dinic <miodrag.dinic@imgtec.com> Signed-off-by: Goran Ferenc <goran.ferenc@imgtec.com> Signed-off-by: Aleksandar Markovic <aleksandar.markovic@imgtec.com> Reviewed-by: James Hogan <james.hogan@imgtec.com> Cc: Bo Hu <bohu@google.com> Cc: Douglas Leung <douglas.leung@imgtec.com> Cc: Jin Qian <jinqian@google.com> Cc: Paul Burton <paul.burton@imgtec.com> Cc: Petar Jovanovic <petar.jovanovic@imgtec.com> Cc: Raghu Gandham <raghu.gandham@imgtec.com> Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/16888/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-09-27MIPS: math-emu: <MADDF|MSUBF>.<D|S>: Fix some cases of infinite inputsAleksandar Markovic
commit 0c64fe6348687f0e1cea9a608eae9d351124a73a upstream. Fix the cases of <MADDF|MSUBF>.<D|S> when any of two multiplicands is infinity. The correct behavior in such cases is affected by the nature of third input. Cases of addition of infinities with opposite signs and subtraction of infinities with same signs may arise and must be handles separately. Also, the value od flags argument (that determines whether the instruction is MADDF or MSUBF) affects the outcome. Relevant examples: MADDF.S fd,fs,ft: If fs contains +inf, ft contains +inf, and fd contains -inf, fd is going to contain indef (without this patch, it used to contain -inf). MSUBF.S fd,fs,ft: If fs contains +inf, ft contains 1.0, and fd contains +0.0, fd is going to contain -inf (without this patch, it used to contain +inf). Fixes: e24c3bec3e8e ("MIPS: math-emu: Add support for the MIPS R6 MADDF FPU instruction") Fixes: 83d43305a1df ("MIPS: math-emu: Add support for the MIPS R6 MSUBF FPU instruction") Signed-off-by: Douglas Leung <douglas.leung@imgtec.com> Signed-off-by: Miodrag Dinic <miodrag.dinic@imgtec.com> Signed-off-by: Goran Ferenc <goran.ferenc@imgtec.com> Signed-off-by: Aleksandar Markovic <aleksandar.markovic@imgtec.com> Reviewed-by: James Hogan <james.hogan@imgtec.com> Cc: Douglas Leung <douglas.leung@imgtec.com> Cc: Bo Hu <bohu@google.com> Cc: Jin Qian <jinqian@google.com> Cc: Paul Burton <paul.burton@imgtec.com> Cc: Petar Jovanovic <petar.jovanovic@imgtec.com> Cc: Raghu Gandham <raghu.gandham@imgtec.com> Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/16887/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-09-27MIPS: math-emu: <MADDF|MSUBF>.<D|S>: Fix NaN propagationAleksandar Markovic
commit e840be6e7057757befc3581e1699e30fe7f0dd51 upstream. Fix the cases of <MADDF|MSUBF>.<D|S> when any of three inputs is any NaN. Correct behavior of <MADDF|MSUBF>.<D|S> fd, fs, ft is following: - if any of inputs is sNaN, return a sNaN using following rules: if only one input is sNaN, return that one; if more than one input is sNaN, order of precedence for return value is fd, fs, ft - if no input is sNaN, but at least one of inputs is qNaN, return a qNaN using following rules: if only one input is qNaN, return that one; if more than one input is qNaN, order of precedence for return value is fd, fs, ft The previous code contained correct handling of some above cases, but not all. Also, such handling was scattered into various cases of "switch (CLPAIR(xc, yc))" statement, and elsewhere. With this patch, this logic is placed in one place, and "switch (CLPAIR(xc, yc))" is significantly simplified. A relevant example: MADDF.S fd,fs,ft: If fs contains qNaN1, ft contains qNaN2, and fd contains qNaN3, fd is going to contain qNaN3 (without this patch, it used to contain qNaN1). Fixes: e24c3bec3e8e ("MIPS: math-emu: Add support for the MIPS R6 MADDF FPU instruction") Fixes: 83d43305a1df ("MIPS: math-emu: Add support for the MIPS R6 MSUBF FPU instruction") Signed-off-by: Miodrag Dinic <miodrag.dinic@imgtec.com> Signed-off-by: Goran Ferenc <goran.ferenc@imgtec.com> Signed-off-by: Aleksandar Markovic <aleksandar.markovic@imgtec.com> Reviewed-by: James Hogan <james.hogan@imgtec.com> Cc: Bo Hu <bohu@google.com> Cc: Douglas Leung <douglas.leung@imgtec.com> Cc: Jin Qian <jinqian@google.com> Cc: Paul Burton <paul.burton@imgtec.com> Cc: Petar Jovanovic <petar.jovanovic@imgtec.com> Cc: Raghu Gandham <raghu.gandham@imgtec.com> Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/16886/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-09-27MIPS: math-emu: Handle zero accumulator case in MADDF and MSUBF separatelyAleksandar Markovic
commit ddbfff7429a75d954bf5bdff9f2222bceb4c236a upstream. If accumulator value is zero, just return the value of previously calculated product. This brings logic in MADDF/MSUBF implementation closer to the logic in ADD/SUB case. Signed-off-by: Miodrag Dinic <miodrag.dinic@imgtec.com> Signed-off-by: Goran Ferenc <goran.ferenc@imgtec.com> Signed-off-by: Aleksandar Markovic <aleksandar.markovic@imgtec.com> Cc: James.Hogan@imgtec.com Cc: Paul.Burton@imgtec.com Cc: Raghu.Gandham@imgtec.com Cc: Leonid.Yegoshin@imgtec.com Cc: Douglas.Leung@imgtec.com Cc: Petar.Jovanovic@imgtec.com Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/16512/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-09-27MIPS: math-emu: MINA.<D|S>: Fix some cases of infinity and zero inputsAleksandar Markovic
commit 304bfe473e70523e591fb1c9223289d355e0bdcb upstream. Fix following special cases for MINA>.<D|S>: - if one of the inputs is zero, and the other is subnormal, normal, or infinity, the value of the former should be returned (that is, a zero). - if one of the inputs is infinity, and the other input is normal, or subnormal, the value of the latter should be returned. The previous implementation's logic for such cases was incorrect - it appears as if it implements MAXA, and not MINA instruction. A relevant example: MINA.S fd,fs,ft: If fs contains 100.0, and ft contains 0.0, fd is going to contain 0.0 (without this patch, it used to contain 100.0). Fixes: a79f5f9ba508 ("MIPS: math-emu: Add support for the MIPS R6 MAX{, A} FPU instruction") Fixes: 4e9561b20e2f ("MIPS: math-emu: Add support for the MIPS R6 MIN{, A} FPU instruction") Signed-off-by: Miodrag Dinic <miodrag.dinic@imgtec.com> Signed-off-by: Goran Ferenc <goran.ferenc@imgtec.com> Signed-off-by: Aleksandar Markovic <aleksandar.markovic@imgtec.com> Reviewed-by: James Hogan <james.hogan@imgtec.com> Cc: Bo Hu <bohu@google.com> Cc: Douglas Leung <douglas.leung@imgtec.com> Cc: Jin Qian <jinqian@google.com> Cc: Paul Burton <paul.burton@imgtec.com> Cc: Petar Jovanovic <petar.jovanovic@imgtec.com> Cc: Raghu Gandham <raghu.gandham@imgtec.com> Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/16885/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-09-27MIPS: math-emu: <MAXA|MINA>.<D|S>: Fix cases of both infinite inputsAleksandar Markovic
commit 3444c4eb534c20e44f0d6670b34263efaf8b531f upstream. Fix the value returned by <MAXA|MINA>.<D|S> fd,fs,ft, if both inputs are infinite. The previous implementation returned always the value contained in ft in such cases. The correct behavior is specified in Mips instruction set manual and is as follows: fs ft MAXA MINA --------------------------------- inf inf inf inf inf -inf inf -inf -inf inf inf -inf -inf -inf -inf -inf A relevant example: MAXA.S fd,fs,ft: If fs contains +inf, and ft contains -inf, fd is going to contain +inf (without this patch, it used to contain -inf). Fixes: a79f5f9ba508 ("MIPS: math-emu: Add support for the MIPS R6 MAX{, A} FPU instruction") Fixes: 4e9561b20e2f ("MIPS: math-emu: Add support for the MIPS R6 MIN{, A} FPU instruction") Signed-off-by: Miodrag Dinic <miodrag.dinic@imgtec.com> Signed-off-by: Goran Ferenc <goran.ferenc@imgtec.com> Signed-off-by: Aleksandar Markovic <aleksandar.markovic@imgtec.com> Reviewed-by: James Hogan <james.hogan@imgtec.com> Cc: Bo Hu <bohu@google.com> Cc: Douglas Leung <douglas.leung@imgtec.com> Cc: Jin Qian <jinqian@google.com> Cc: Paul Burton <paul.burton@imgtec.com> Cc: Petar Jovanovic <petar.jovanovic@imgtec.com> Cc: Raghu Gandham <raghu.gandham@imgtec.com> Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/16884/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-09-27MIPS: math-emu: <MAXA|MINA>.<D|S>: Fix cases of input values with opposite signsAleksandar Markovic
commit 1a41b3b441508ae63b1a9ec699ec94065739eb60 upstream. Fix the value returned by <MAXA|MINA>.<D|S>, if the inputs are normal fp numbers of the same absolute value, but opposite signs. A relevant example: MAXA.S fd,fs,ft: If fs contains -3.0, and ft contains +3.0, fd is going to contain +3.0 (without this patch, it used to contain -3.0). Fixes: a79f5f9ba508 ("MIPS: math-emu: Add support for the MIPS R6 MAX{, A} FPU instruction") Fixes: 4e9561b20e2f ("MIPS: math-emu: Add support for the MIPS R6 MIN{, A} FPU instruction") Signed-off-by: Miodrag Dinic <miodrag.dinic@imgtec.com> Signed-off-by: Goran Ferenc <goran.ferenc@imgtec.com> Signed-off-by: Aleksandar Markovic <aleksandar.markovic@imgtec.com> Reviewed-by: James Hogan <james.hogan@imgtec.com> Cc: Bo Hu <bohu@google.com> Cc: Douglas Leung <douglas.leung@imgtec.com> Cc: Jin Qian <jinqian@google.com> Cc: Paul Burton <paul.burton@imgtec.com> Cc: Petar Jovanovic <petar.jovanovic@imgtec.com> Cc: Raghu Gandham <raghu.gandham@imgtec.com> Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/16883/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-09-27MIPS: math-emu: <MAX|MIN>.<D|S>: Fix cases of both inputs negativeAleksandar Markovic
commit aabf5cf02e22ebc4e541adf835910f388b6c3e65 upstream. Fix the value returned by <MAX|MIN>.<D|S>, if both inputs are negative normal fp numbers. The previous logic did not take into account that if both inputs have the same sign, there should be separate treatment of the cases when both inputs are negative and when both inputs are positive. A relevant example: MAX.S fd,fs,ft: If fs contains -5.0, and ft contains -7.0, fd is going to contain -5.0 (without this patch, it used to contain -7.0). Fixes: a79f5f9ba508 ("MIPS: math-emu: Add support for the MIPS R6 MAX{, A} FPU instruction") Fixes: 4e9561b20e2f ("MIPS: math-emu: Add support for the MIPS R6 MIN{, A} FPU instruction") Signed-off-by: Miodrag Dinic <miodrag.dinic@imgtec.com> Signed-off-by: Goran Ferenc <goran.ferenc@imgtec.com> Signed-off-by: Aleksandar Markovic <aleksandar.markovic@imgtec.com> Reviewed-by: James Hogan <james.hogan@imgtec.com> Cc: Bo Hu <bohu@google.com> Cc: Douglas Leung <douglas.leung@imgtec.com> Cc: Jin Qian <jinqian@google.com> Cc: Paul Burton <paul.burton@imgtec.com> Cc: Petar Jovanovic <petar.jovanovic@imgtec.com> Cc: Raghu Gandham <raghu.gandham@imgtec.com> Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/16882/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-09-27MIPS: math-emu: <MAX|MAXA|MIN|MINA>.<D|S>: Fix cases of both inputs zeroAleksandar Markovic
commit 15560a58bfd4ff82cdd16b2270d4ef9b06d2cc4d upstream. Fix the value returned by <MAX|MAXA|MIN|MINA>.<D|S>, if both inputs are zeros. The right behavior in such cases is stated in instruction reference manual and is as follows: fs ft MAX MIN MAXA MINA --------------------------------------------- 0 0 0 0 0 0 0 -0 0 -0 0 -0 -0 0 0 -0 0 -0 -0 -0 -0 -0 -0 -0 Prior to this patch, some of the above cases were yielding correct results. However, for the sake of code consistency, all such cases are rewritten in this patch. A relevant example: MAX.S fd,fs,ft: If fs contains +0.0, and ft contains -0.0, fd is going to contain +0.0 (without this patch, it used to contain -0.0). Fixes: a79f5f9ba508 ("MIPS: math-emu: Add support for the MIPS R6 MAX{, A} FPU instruction") Fixes: 4e9561b20e2f ("MIPS: math-emu: Add support for the MIPS R6 MIN{, A} FPU instruction") Signed-off-by: Miodrag Dinic <miodrag.dinic@imgtec.com> Signed-off-by: Goran Ferenc <goran.ferenc@imgtec.com> Signed-off-by: Aleksandar Markovic <aleksandar.markovic@imgtec.com> Reviewed-by: James Hogan <james.hogan@imgtec.com> Cc: Bo Hu <bohu@google.com> Cc: Douglas Leung <douglas.leung@imgtec.com> Cc: Jin Qian <jinqian@google.com> Cc: Paul Burton <paul.burton@imgtec.com> Cc: Petar Jovanovic <petar.jovanovic@imgtec.com> Cc: Raghu Gandham <raghu.gandham@imgtec.com> Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/16881/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-09-27MIPS: math-emu: <MAX|MAXA|MIN|MINA>.<D|S>: Fix quiet NaN propagationAleksandar Markovic
commit e78bf0dc4789bdea1453595ae89e8db65918e22e upstream. Fix the value returned by <MAX|MAXA|MIN|MINA>.<D|S> fd,fs,ft, if both inputs are quiet NaNs. The <MAX|MAXA|MIN|MINA>.<D|S> specifications state that the returned value in such cases should be the quiet NaN contained in register fs. A relevant example: MAX.S fd,fs,ft: If fs contains qNaN1, and ft contains qNaN2, fd is going to contain qNaN1 (without this patch, it used to contain qNaN2). Fixes: a79f5f9ba508 ("MIPS: math-emu: Add support for the MIPS R6 MAX{, A} FPU instruction") Fixes: 4e9561b20e2f ("MIPS: math-emu: Add support for the MIPS R6 MIN{, A} FPU instruction") Signed-off-by: Miodrag Dinic <miodrag.dinic@imgtec.com> Signed-off-by: Goran Ferenc <goran.ferenc@imgtec.com> Signed-off-by: Aleksandar Markovic <aleksandar.markovic@imgtec.com> Reviewed-by: James Hogan <james.hogan@imgtec.com> Cc: Bo Hu <bohu@google.com> Cc: Douglas Leung <douglas.leung@imgtec.com> Cc: Jin Qian <jinqian@google.com> Cc: Paul Burton <paul.burton@imgtec.com> Cc: Petar Jovanovic <petar.jovanovic@imgtec.com> Cc: Raghu Gandham <raghu.gandham@imgtec.com> Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/16880/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-08-16MIPS: DEC: Fix an int-handler.S CPU_DADDI_WORKAROUNDS regressionMaciej W. Rozycki
commit 68fe55680d0f3342969f49412fceabb90bdfadba upstream. Fix a commit 3021773c7c3e ("MIPS: DEC: Avoid la pseudo-instruction in delay slots") regression and remove assembly errors: arch/mips/dec/int-handler.S: Assembler messages: arch/mips/dec/int-handler.S:162: Error: Macro used $at after ".set noat" arch/mips/dec/int-handler.S:163: Error: Macro used $at after ".set noat" arch/mips/dec/int-handler.S:229: Error: Macro used $at after ".set noat" arch/mips/dec/int-handler.S:230: Error: Macro used $at after ".set noat" triggering with with the CPU_DADDI_WORKAROUNDS option set and the DADDIU instruction. This is because with that option in place the instruction becomes a macro, which expands to an LI/DADDU (or actually ADDIU/DADDU) sequence that uses $at as a temporary register. With CPU_DADDI_WORKAROUNDS we only support `-msym32' compilation though, and this is already enforced in arch/mips/Makefile, so choose the 32-bit expansion variant for the supported configurations and then replace the 64-bit variant with #error just in case. Fixes: 3021773c7c3e ("MIPS: DEC: Avoid la pseudo-instruction in delay slots") Signed-off-by: Maciej W. Rozycki <macro@linux-mips.org> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/16893/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-27MIPS: Fix a typo: s/preset/present/ in r2-to-r6 emulation error messageMaciej W. Rozycki
commit 27fe2200dad2de8207a694024a7b9037dff1b280 upstream. This is a user-visible message, so we want it to be spelled correctly. Fixes: 5f9f41c474be ("MIPS: kernel: Prepare the JR instruction for emulation on MIPS R6") Signed-off-by: Maciej W. Rozycki <macro@imgtec.com> Cc: James Hogan <james.hogan@imgtec.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/16400/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-27MIPS: Send SIGILL for R6 branches in `__compute_return_epc_for_insn'Maciej W. Rozycki
commit a60b1a5bf88a250f1a77977c0224e502c901c77b upstream. Fix: * commit 8467ca0122e2 ("MIPS: Emulate the new MIPS R6 branch compact (BC) instruction"), * commit 84fef630127a ("MIPS: Emulate the new MIPS R6 BALC instruction"), * commit 69b9a2fd05a3 ("MIPS: Emulate the new MIPS R6 BEQZC and JIC instructions"), * commit 28d6f93d201d ("MIPS: Emulate the new MIPS R6 BNEZC and JIALC instructions"), * commit c893ce38b265 ("MIPS: Emulate the new MIPS R6 BOVC, BEQC and BEQZALC instructions") and send SIGILL rather than returning -SIGILL for R6 branch and jump instructions. Returning -SIGILL is never correct as the API defines this function's result upon error to be -EFAULT and a signal actually issued. Fixes: 8467ca0122e2 ("MIPS: Emulate the new MIPS R6 branch compact (BC) instruction") Fixes: 84fef630127a ("MIPS: Emulate the new MIPS R6 BALC instruction") Fixes: 69b9a2fd05a3 ("MIPS: Emulate the new MIPS R6 BEQZC and JIC instructions") Fixes: 28d6f93d201d ("MIPS: Emulate the new MIPS R6 BNEZC and JIALC instructions") Fixes: c893ce38b265 ("MIPS: Emulate the new MIPS R6 BOVC, BEQC and BEQZALC instructions") Signed-off-by: Maciej W. Rozycki <macro@imgtec.com> Cc: James Hogan <james.hogan@imgtec.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/16399/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-27MIPS: Send SIGILL for linked branches in `__compute_return_epc_for_insn'Maciej W. Rozycki
commit fef40be6da856afead4177aaa9d869a66fb3381f upstream. Fix commit 319824eabc3f ("MIPS: kernel: branch: Do not emulate the branch likelies on MIPS R6") and also send SIGILL rather than returning -SIGILL for BLTZAL, BLTZALL, BGEZAL and BGEZALL instruction encodings no longer supported in R6, except where emulated. Returning -SIGILL is never correct as the API defines this function's result upon error to be -EFAULT and a signal actually issued. Fixes: 319824eabc3f ("MIPS: kernel: branch: Do not emulate the branch likelies on MIPS R6") Signed-off-by: Maciej W. Rozycki <macro@imgtec.com> Cc: James Hogan <james.hogan@imgtec.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/16398/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-27MIPS: Rename `sigill_r6' to `sigill_r2r6' in `__compute_return_epc_for_insn'Maciej W. Rozycki
commit 1f4edde422961397cf4470b347958c13c6a740bb upstream. Use the more accurate `sigill_r2r6' name for the label used in the case of sending SIGILL in the absence of the instruction emulator for an earlier ISA level instruction that has been removed as from the R6 ISA, so that the `sigill_r6' name is freed for the situation where an R6 instruction is not supposed to be interpreted, because the executing processor does not support the R6 ISA. Signed-off-by: Maciej W. Rozycki <macro@imgtec.com> Cc: James Hogan <james.hogan@imgtec.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/16397/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-27MIPS: Send SIGILL for BPOSGE32 in `__compute_return_epc_for_insn'Maciej W. Rozycki
commit 7b82c1058ac1f8f8b9f2b8786b1f710a57a870a8 upstream. Fix commit e50c0a8fa60d ("Support the MIPS32 / MIPS64 DSP ASE.") and send SIGILL rather than SIGBUS whenever an unimplemented BPOSGE32 DSP ASE instruction has been encountered in `__compute_return_epc_for_insn' as our Reserved Instruction exception handler would in response to an attempt to actually execute the instruction. Sending SIGBUS only makes sense for the unaligned PC case, since moved to `__compute_return_epc'. Adjust function documentation accordingly, correct formatting and use `pr_info' rather than `printk' as the other exit path already does. Fixes: e50c0a8fa60d ("Support the MIPS32 / MIPS64 DSP ASE.") Signed-off-by: Maciej W. Rozycki <macro@imgtec.com> Cc: James Hogan <james.hogan@imgtec.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/16396/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-27MIPS: math-emu: Prevent wrong ISA mode instruction emulationMaciej W. Rozycki
commit 13769ebad0c42738831787e27c7c7f982e7da579 upstream. Terminate FPU emulation immediately whenever an ISA mode switch has been observed. This is so that we do not interpret machine code in the wrong mode, for example when a regular MIPS FPU instruction has been placed in a delay slot of a jump that switches into the MIPS16 mode, as with the following code (taken from a GCC test suite case): 00400650 <set_fast_math>: 400650: 3c020100 lui v0,0x100 400654: 03e00008 jr ra 400658: 44c2f800 ctc1 v0,c1_fcsr 40065c: 00000000 nop [...] 004012d0 <__libc_csu_init>: 4012d0: f000 6a02 li v0,2 4012d4: f150 0b1c la v1,3f9430 <_DYNAMIC-0x6df0> 4012d8: f400 3240 sll v0,16 4012dc: e269 addu v0,v1 4012de: 659a move gp,v0 4012e0: f00c 64f6 save a0-a2,48,ra,s0-s1 4012e4: 673c move s1,gp 4012e6: f010 9978 lw v1,-32744(s1) 4012ea: d204 sw v0,16(sp) 4012ec: eb40 jalr v1 4012ee: 653b move t9,v1 4012f0: f010 997c lw v1,-32740(s1) 4012f4: f030 9920 lw s1,-32736(s1) 4012f8: e32f subu v1,s1 4012fa: 326b sra v0,v1,2 4012fc: d206 sw v0,24(sp) 4012fe: 220c beqz v0,401318 <__libc_csu_init+0x48> 401300: 6800 li s0,0 401302: 99e0 lw a3,0(s1) 401304: 4801 addiu s0,1 401306: 960e lw a2,56(sp) 401308: 4904 addiu s1,4 40130a: 950d lw a1,52(sp) 40130c: 940c lw a0,48(sp) 40130e: ef40 jalr a3 401310: 653f move t9,a3 401312: 9206 lw v0,24(sp) 401314: ea0a cmp v0,s0 401316: 61f5 btnez 401302 <__libc_csu_init+0x32> 401318: 6476 restore 48,ra,s0-s1 40131a: e8a0 jrc ra Here `set_fast_math' is called from `40130e' (`40130f' with the ISA bit) and emulation triggers for the CTC1 instruction. As it is in a jump delay slot emulation continues from `401312' (`401313' with the ISA bit). However we have no path to handle MIPS16 FPU code emulation, because there are no MIPS16 FPU instructions. So the default emulation path is taken, interpreting a 32-bit word fetched by `get_user' from `401313' as a regular MIPS instruction, which is: 401313: f5ea0a92 sdc1 $f10,2706(t7) This makes the FPU emulator proceed with the supposed SDC1 instruction and consequently makes the program considered here terminate with SIGSEGV. A similar although less severe issue exists with pure-microMIPS processors in the case where similarly an FPU instruction is emulated in a delay slot of a register jump that (incorrectly) switches into the regular MIPS mode. A subsequent instruction fetch from the jump's target is supposed to cause an Address Error exception, however instead we proceed with regular MIPS FPU emulation. For simplicity then, always terminate the emulation loop whenever a mode change is detected, denoted by an ISA mode bit flip. As from commit 377cb1b6c16a ("MIPS: Disable MIPS16/microMIPS crap for platforms not supporting these ASEs.") the result of `get_isa16_mode' can be hardcoded to 0, so we need to examine the ISA mode bit by hand. This complements commit 102cedc32a6e ("MIPS: microMIPS: Floating point support.") which added JALX decoding to FPU emulation. Fixes: 102cedc32a6e ("MIPS: microMIPS: Floating point support.") Signed-off-by: Maciej W. Rozycki <macro@imgtec.com> Cc: James Hogan <james.hogan@imgtec.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/16393/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-27MIPS: Fix unaligned PC interpretation in `compute_return_epc'Maciej W. Rozycki
commit 11a3799dbeb620bf0400b1fda5cc2c6bea55f20a upstream. Fix a regression introduced with commit fb6883e5809c ("MIPS: microMIPS: Support handling of delay slots.") and defer to `__compute_return_epc' if the ISA bit is set in EPC with non-MIPS16, non-microMIPS hardware, which will then arrange for a SIGBUS due to an unaligned instruction reference. Returning EPC here is never correct as the API defines this function's result to be either a negative error code on failure or one of 0 and BRANCH_LIKELY_TAKEN on success. Fixes: fb6883e5809c ("MIPS: microMIPS: Support handling of delay slots.") Signed-off-by: Maciej W. Rozycki <macro@imgtec.com> Cc: James Hogan <james.hogan@imgtec.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/16395/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-27MIPS: Actually decode JALX in `__compute_return_epc_for_insn'Maciej W. Rozycki
commit a9db101b735a9d49295326ae41f610f6da62b08c upstream. Complement commit fb6883e5809c ("MIPS: microMIPS: Support handling of delay slots.") and actually decode the regular MIPS JALX major instruction opcode, the handling of which has been added with the said commit for EPC calculation in `__compute_return_epc_for_insn'. Fixes: fb6883e5809c ("MIPS: microMIPS: Support handling of delay slots.") Signed-off-by: Maciej W. Rozycki <macro@imgtec.com> Cc: James Hogan <james.hogan@imgtec.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/16394/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-27MIPS: Save static registers before sysmipsJames Hogan
commit 49955d84cd9ccdca5a16a495e448e1a06fad9e49 upstream. The MIPS sysmips system call handler may return directly from the MIPS_ATOMIC_SET case (mips_atomic_set()) to syscall_exit. This path restores the static (callee saved) registers, however they won't have been saved on entry to the system call. Use the save_static_function() macro to create a __sys_sysmips wrapper function which saves the static registers before calling sys_sysmips, so that the correct static register state is restored by syscall_exit. Fixes: f1e39a4a616c ("MIPS: Rewrite sysmips(MIPS_ATOMIC_SET, ...) in C with inline assembler") Signed-off-by: James Hogan <james.hogan@imgtec.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/16149/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-27MIPS: Fix MIPS I ISA /proc/cpuinfo reportingMaciej W. Rozycki
commit e5f5a5b06e51a36f6ddf31a4a485358263953a3d upstream. Correct a commit 515a6393dbac ("MIPS: kernel: proc: Add MIPS R6 support to /proc/cpuinfo") regression that caused MIPS I systems to show no ISA levels supported in /proc/cpuinfo, e.g.: system type : Digital DECstation 2100/3100 machine : Unknown processor : 0 cpu model : R3000 V2.0 FPU V2.0 BogoMIPS : 10.69 wait instruction : no microsecond timers : no tlb_entries : 64 extra interrupt vector : no hardware watchpoint : no isa : ASEs implemented : shadow register sets : 1 kscratch registers : 0 package : 0 core : 0 VCED exceptions : not available VCEI exceptions : not available and similarly exclude `mips1' from the ISA list for any processors below MIPSr1. This is because the condition to show `mips1' on has been made `cpu_has_mips_r1' rather than newly-introduced `cpu_has_mips_1'. Use the correct condition then. Fixes: 515a6393dbac ("MIPS: kernel: proc: Add MIPS R6 support to /proc/cpuinfo") Signed-off-by: Maciej W. Rozycki <macro@linux-mips.org> Reviewed-by: James Hogan <james.hogan@imgtec.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/16758/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-27MIPS: Negate error syscall return in traceJames Hogan
commit 4f32a39d49b25eaa66d2420f1f03d371ea4cd906 upstream. The sys_exit trace event takes a single return value for the system call, which MIPS passes the value of the $v0 (result) register, however MIPS returns positive error codes in $v0 with $a3 specifying that $v0 contains an error code. As a result erroring system calls are traced returning positive error numbers that can't always be distinguished from success. Use regs_return_value() to negate the error code if $a3 is set. Fixes: 1d7bf993e073 ("MIPS: ftrace: Add support for syscall tracepoints.") Signed-off-by: James Hogan <james.hogan@imgtec.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/16651/ Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-27MIPS: Fix mips_atomic_set() with EVAJames Hogan
commit 4915e1b043d6286928207b1f6968197b50407294 upstream. EVA linked loads (LLE) and conditional stores (SCE) should be used on EVA kernels for the MIPS_ATOMIC_SET operation of the sysmips system call, or else the atomic set will apply to the kernel view of the virtual address space (potentially unmapped on EVA kernels) rather than the user view (TLB mapped). Signed-off-by: James Hogan <james.hogan@imgtec.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/16151/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-27MIPS: Fix mips_atomic_set() retry conditionJames Hogan
commit 2ec420b26f7b6ff332393f0bb5a7d245f7ad87f0 upstream. The inline asm retry check in the MIPS_ATOMIC_SET operation of the sysmips system call has been backwards since commit f1e39a4a616c ("MIPS: Rewrite sysmips(MIPS_ATOMIC_SET, ...) in C with inline assembler") merged in v2.6.32, resulting in the non R10000_LLSC_WAR case retrying until the operation was inatomic, before returning the new value that was probably just written multiple times instead of the old value. Invert the branch condition to fix that particular issue. Fixes: f1e39a4a616c ("MIPS: Rewrite sysmips(MIPS_ATOMIC_SET, ...) in C with inline assembler") Signed-off-by: James Hogan <james.hogan@imgtec.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/16148/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-05MIPS: Fix IRQ tracing & lockdep when reschedulingPaul Burton
commit d8550860d910c6b7b70f830f59003b33daaa52c9 upstream. When the scheduler sets TIF_NEED_RESCHED & we call into the scheduler from arch/mips/kernel/entry.S we disable interrupts. This is true regardless of whether we reach work_resched from syscall_exit_work, resume_userspace or by looping after calling schedule(). Although we disable interrupts in these paths we don't call trace_hardirqs_off() before calling into C code which may acquire locks, and we therefore leave lockdep with an inconsistent view of whether interrupts are disabled or not when CONFIG_PROVE_LOCKING & CONFIG_DEBUG_LOCKDEP are both enabled. Without tracing this interrupt state lockdep will print warnings such as the following once a task returns from a syscall via syscall_exit_partial with TIF_NEED_RESCHED set: [ 49.927678] ------------[ cut here ]------------ [ 49.934445] WARNING: CPU: 0 PID: 1 at kernel/locking/lockdep.c:3687 check_flags.part.41+0x1dc/0x1e8 [ 49.946031] DEBUG_LOCKS_WARN_ON(current->hardirqs_enabled) [ 49.946355] CPU: 0 PID: 1 Comm: init Not tainted 4.10.0-00439-gc9fd5d362289-dirty #197 [ 49.963505] Stack : 0000000000000000 ffffffff81bb5d6a 0000000000000006 ffffffff801ce9c4 [ 49.974431] 0000000000000000 0000000000000000 0000000000000000 000000000000004a [ 49.985300] ffffffff80b7e487 ffffffff80a24498 a8000000ff160000 ffffffff80ede8b8 [ 49.996194] 0000000000000001 0000000000000000 0000000000000000 0000000077c8030c [ 50.007063] 000000007fd8a510 ffffffff801cd45c 0000000000000000 a8000000ff127c88 [ 50.017945] 0000000000000000 ffffffff801cf928 0000000000000001 ffffffff80a24498 [ 50.028827] 0000000000000000 0000000000000001 0000000000000000 0000000000000000 [ 50.039688] 0000000000000000 a8000000ff127bd0 0000000000000000 ffffffff805509bc [ 50.050575] 00000000140084e0 0000000000000000 0000000000000000 0000000000040a00 [ 50.061448] 0000000000000000 ffffffff8010e1b0 0000000000000000 ffffffff805509bc [ 50.072327] ... [ 50.076087] Call Trace: [ 50.079869] [<ffffffff8010e1b0>] show_stack+0x80/0xa8 [ 50.086577] [<ffffffff805509bc>] dump_stack+0x10c/0x190 [ 50.093498] [<ffffffff8015dde0>] __warn+0xf0/0x108 [ 50.099889] [<ffffffff8015de34>] warn_slowpath_fmt+0x3c/0x48 [ 50.107241] [<ffffffff801c15b4>] check_flags.part.41+0x1dc/0x1e8 [ 50.114961] [<ffffffff801c239c>] lock_is_held_type+0x8c/0xb0 [ 50.122291] [<ffffffff809461b8>] __schedule+0x8c0/0x10f8 [ 50.129221] [<ffffffff80946a60>] schedule+0x30/0x98 [ 50.135659] [<ffffffff80106278>] work_resched+0x8/0x34 [ 50.142397] ---[ end trace 0cb4f6ef5b99fe21 ]--- [ 50.148405] possible reason: unannotated irqs-off. [ 50.154600] irq event stamp: 400463 [ 50.159566] hardirqs last enabled at (400463): [<ffffffff8094edc8>] _raw_spin_unlock_irqrestore+0x40/0xa8 [ 50.171981] hardirqs last disabled at (400462): [<ffffffff8094eb98>] _raw_spin_lock_irqsave+0x30/0xb0 [ 50.183897] softirqs last enabled at (400450): [<ffffffff8016580c>] __do_softirq+0x4ac/0x6a8 [ 50.195015] softirqs last disabled at (400425): [<ffffffff80165e78>] irq_exit+0x110/0x128 Fix this by using the TRACE_IRQS_OFF macro to call trace_hardirqs_off() when CONFIG_TRACE_IRQFLAGS is enabled. This is done before invoking schedule() following the work_resched label because: 1) Interrupts are disabled regardless of the path we take to reach work_resched() & schedule(). 2) Performing the tracing here avoids the need to do it in paths which disable interrupts but don't call out to C code before hitting a path which uses the RESTORE_SOME macro that will call trace_hardirqs_on() or trace_hardirqs_off() as appropriate. We call trace_hardirqs_on() using the TRACE_IRQS_ON macro before calling syscall_trace_leave() for similar reasons, ensuring that lockdep has a consistent view of state after we re-enable interrupts. Signed-off-by: Paul Burton <paul.burton@imgtec.com> Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/15385/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-05MIPS: pm-cps: Drop manual cache-line alignment of ready_countPaul Burton
commit 161c51ccb7a6faf45ffe09aa5cf1ad85ccdad503 upstream. We allocate memory for a ready_count variable per-CPU, which is accessed via a cached non-coherent TLB mapping to perform synchronisation between threads within the core using LL/SC instructions. In order to ensure that the variable is contained within its own data cache line we allocate 2 lines worth of memory & align the resulting pointer to a line boundary. This is however unnecessary, since kmalloc is guaranteed to return memory which is at least cache-line aligned (see ARCH_DMA_MINALIGN). Stop the redundant manual alignment. Besides cleaning up the code & avoiding needless work, this has the side effect of avoiding an arithmetic error found by Bryan on 64 bit systems due to the 32 bit size of the former dlinesz. This led the ready_count variable to have its upper 32b cleared erroneously for MIPS64 kernels, causing problems when ready_count was later used on MIPS64 via cpuidle. Signed-off-by: Paul Burton <paul.burton@imgtec.com> Fixes: 3179d37ee1ed ("MIPS: pm-cps: add PM state entry code for CPS systems") Reported-by: Bryan O'Donoghue <bryan.odonoghue@imgtec.com> Reviewed-by: Bryan O'Donoghue <bryan.odonoghue@imgtec.com> Tested-by: Bryan O'Donoghue <bryan.odonoghue@imgtec.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/15383/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-05MIPS: Avoid accidental raw backtraceJames Hogan
commit 854236363370995a609a10b03e35fd3dc5e9e4a1 upstream. Since commit 81a76d7119f6 ("MIPS: Avoid using unwind_stack() with usermode") show_backtrace() invokes the raw backtracer when cp0_status & ST0_KSU indicates user mode to fix issues on EVA kernels where user and kernel address spaces overlap. However this is used by show_stack() which creates its own pt_regs on the stack and leaves cp0_status uninitialised in most of the code paths. This results in the non deterministic use of the raw back tracer depending on the previous stack content. show_stack() deals exclusively with kernel mode stacks anyway, so explicitly initialise regs.cp0_status to KSU_KERNEL (i.e. 0) to ensure we get a useful backtrace. Fixes: 81a76d7119f6 ("MIPS: Avoid using unwind_stack() with usermode") Signed-off-by: James Hogan <james.hogan@imgtec.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/16656/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-05MIPS: head: Reorder instructions missing a delay slotKarl Beldan
commit 25d8b92e0af75d72ce8b99e63e5a449cc0888efa upstream. In this sequence the 'move' is assumed in the delay slot of the 'beq', but head.S is in reorder mode and the former gets pushed one 'nop' farther by the assembler. The corrected behavior made booting with an UHI supplied dtb erratic. Fixes: 15f37e158892 ("MIPS: store the appended dtb address in a variable") Signed-off-by: Karl Beldan <karl.beldan+oss@gmail.com> Reviewed-by: James Hogan <james.hogan@imgtec.com> Cc: Jonas Gorski <jogo@openwrt.org> Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/16614/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-06-24mm: larger stack guard gap, between vmasHugh Dickins
commit 1be7107fbe18eed3e319a6c3e83c78254b693acb upstream. Stack guard page is a useful feature to reduce a risk of stack smashing into a different mapping. We have been using a single page gap which is sufficient to prevent having stack adjacent to a different mapping. But this seems to be insufficient in the light of the stack usage in userspace. E.g. glibc uses as large as 64kB alloca() in many commonly used functions. Others use constructs liks gid_t buffer[NGROUPS_MAX] which is 256kB or stack strings with MAX_ARG_STRLEN. This will become especially dangerous for suid binaries and the default no limit for the stack size limit because those applications can be tricked to consume a large portion of the stack and a single glibc call could jump over the guard page. These attacks are not theoretical, unfortunatelly. Make those attacks less probable by increasing the stack guard gap to 1MB (on systems with 4k pages; but make it depend on the page size because systems with larger base pages might cap stack allocations in the PAGE_SIZE units) which should cover larger alloca() and VLA stack allocations. It is obviously not a full fix because the problem is somehow inherent, but it should reduce attack space a lot. One could argue that the gap size should be configurable from userspace, but that can be done later when somebody finds that the new 1MB is wrong for some special case applications. For now, add a kernel command line option (stack_guard_gap) to specify the stack gap size (in page units). Implementation wise, first delete all the old code for stack guard page: because although we could get away with accounting one extra page in a stack vma, accounting a larger gap can break userspace - case in point, a program run with "ulimit -S -v 20000" failed when the 1MB gap was counted for RLIMIT_AS; similar problems could come with RLIMIT_MLOCK and strict non-overcommit mode. Instead of keeping gap inside the stack vma, maintain the stack guard gap as a gap between vmas: using vm_start_gap() in place of vm_start (or vm_end_gap() in place of vm_end if VM_GROWSUP) in just those few places which need to respect the gap - mainly arch_get_unmapped_area(), and and the vma tree's subtree_gap support for that. Original-patch-by: Oleg Nesterov <oleg@redhat.com> Original-patch-by: Michal Hocko <mhocko@suse.com> Signed-off-by: Hugh Dickins <hughd@google.com> Acked-by: Michal Hocko <mhocko@suse.com> Tested-by: Helge Deller <deller@gmx.de> # parisc Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> [wt: backport to 4.11: adjust context] [wt: backport to 4.9: adjust context ; kernel doc was not in admin-guide] Signed-off-by: Willy Tarreau <w@1wt.eu> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-06-24MIPS: .its targets depend on vmlinuxPaul Burton
commit bcd7c45e0d5a82be9a64b90050f0e09d41a50758 upstream. The .its targets require information about the kernel binary, such as its entry point, which is extracted from the vmlinux ELF. We therefore require that the ELF is built before the .its files are generated. Declare this requirement in the Makefile such that make will ensure this is always the case, otherwise in corner cases we can hit issues as the .its is generated with an incorrect (either invalid or stale) entry point. Signed-off-by: Paul Burton <paul.burton@imgtec.com> Fixes: cf2a5e0bb4c6 ("MIPS: Support generating Flattened Image Trees (.itb)") Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/16179/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>