kernel.git/arch/mips/kernel/ptrace.c, branch linux-4.19.y

MIPS: Add FP_MODE regset support

2018-07-19T20:58:44Z

Define an NT_MIPS_FP_MODE core file note and implement a corresponding regset holding the state handled by PR_SET_FP_MODE and PR_GET_FP_MODE prctl(2) requests. This lets debug software correctly interpret the contents of floating-point general registers both in live debugging and in core files, and also switch floating-point modes of a live process. [paul.burton@mips.com: - Changed NT_MIPS_FP_MODE to 0x801 to match first nibble of NT_MIPS_DSP, which was also changed to avoid a conflict.] Signed-off-by: Maciej W. Rozycki Signed-off-by: Paul Burton Patchwork: https://patchwork.linux-mips.org/patch/19331/ Cc: James Hogan Cc: Ralf Baechle Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org

MIPS: Add DSP ASE regset support

2018-07-19T20:47:51Z

Define an NT_MIPS_DSP core file note type and implement a corresponding regset holding the DSP ASE register context, following the layout of the `mips_dsp_state' structure, except for the DSPControl register stored as a 64-bit rather than 32-bit quantity in a 64-bit note. The lack of DSP ASE register saving to core files can be considered a design flaw with commit e50c0a8fa60d ("Support the MIPS32 / MIPS64 DSP ASE."), leading to an incomplete state being saved. Consequently no DSP ASE regset has been created with commit 7aeb753b5353 ("MIPS: Implement task_user_regset_view."), when regset support was added to the MIPS port. Additionally there is no way for ptrace(2) to correctly access the DSP accumulator registers in n32 processes with the existing interfaces. This is due to 32-bit truncation of data passed with PTRACE_PEEKUSR and PTRACE_POKEUSR requests, which cannot be avoided owing to how the data types for ptrace(3) have been defined. This new NT_MIPS_DSP regset fills the missing interface gap. [paul.burton@mips.com: - Change NT_MIPS_DSP to 0x800 to avoid conflict with NT_VMCOREDD introduced by commit 2724273e8fd0 ("vmcore: add API to collect hardware dump in second kernel"). - Drop stable tag. Whilst I agree the lack of this functionality can be considered a flaw in earlier DSP ASE support, it's still new functionality which doesn't meet up to the requirements set out in Documentation/process/stable-kernel-rules.rst.] Signed-off-by: Maciej W. Rozycki Signed-off-by: Paul Burton References: 7aeb753b5353 ("MIPS: Implement task_user_regset_view.") Patchwork: https://patchwork.linux-mips.org/patch/19330/ Cc: Alexander Viro Cc: James Hogan Cc: Ralf Baechle Cc: linux-fsdevel@vger.kernel.org Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org

MIPS: Correct the 64-bit DSP accumulator register size

2018-07-19T20:47:21Z

Use the `unsigned long' rather than `__u32' type for DSP accumulator registers, like with the regular MIPS multiply/divide accumulator and general-purpose registers, as all are 64-bit in 64-bit implementations and using a 32-bit data type leads to contents truncation on context saving. Update `arch_ptrace' and `compat_arch_ptrace' accordingly, removing casts that are similarly not used with multiply/divide accumulator or general-purpose register accesses. Signed-off-by: Maciej W. Rozycki Signed-off-by: Paul Burton Fixes: e50c0a8fa60d ("Support the MIPS32 / MIPS64 DSP ASE.") Patchwork: https://patchwork.linux-mips.org/patch/19329/ Cc: Alexander Viro Cc: James Hogan Cc: Ralf Baechle Cc: linux-fsdevel@vger.kernel.org Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org Cc: stable@vger.kernel.org # 2.6.15+

Merge tag 'mips_4.18' of git://git.kernel.org/pub/scm/linux/kernel/git/mips/linux

2018-06-12T19:56:02Z

Pull MIPS updates from James Hogan: "These are the main MIPS changes for 4.18. Rough overview: - MAINTAINERS: Add Paul Burton as MIPS co-maintainer - Misc: Generic compiler intrinsics, Y2038 improvements, Perf+MT fixes - Platform support: Netgear WNR1000 V3, Microsemi Ocelot integrated switch, Ingenic watchdog cleanups More detailed summary: Maintainers: - Add Paul Burton as MIPS co-maintainer, as I soon won't have access to much MIPS hardware, nor enough time to properly maintain MIPS on my own. Miscellaneous: - Use generic GCC library routines from lib/ - Add notrace to generic ucmpdi2 implementation - Rename compiler intrinsic selects to GENERIC_LIB_* - vmlinuz: Use generic ashldi3 - y2038: Convert update/read_persistent_clock() to *_clock64() - sni: Remove read_persistent_clock() - perf: Fix perf with MT counting other threads - Probe for per-TC perf counters in cpu-probe.c - Use correct VPE ID for VPE tracing Minor cleanups: - Avoid unneeded built-in.a in DTS dirs - sc-debugfs: Re-use kstrtobool_from_user - memset.S: Reinstate delay slot indentation - VPE: Fix spelling "uneeded" -> "Unneeded" Platform support: BCM47xx: - Add support for Netgear WNR1000 V3 - firmware: Support small NVRAM partitions - Use __initdata for LEDs platform data Ingenic: - Watchdog driver & platform code improvements: - Disable clock after stopping counter - Use devm_* functions - Drop module remove function - Move platform reset code to restart handler in driver - JZ4740: Convert watchdog instantiation to DT - JZ4780: Fix watchdog DT node - qi_lb60_defconfig: Enable watchdog driver Microsemi: - Ocelot: Add support for integrated switch - pcb123: Connect phys to ports" * tag 'mips_4.18' of git://git.kernel.org/pub/scm/linux/kernel/git/mips/linux: (30 commits) MAINTAINERS: Add Paul Burton as MIPS co-maintainer MIPS: ptrace: Make FPU context layout comments match reality MIPS: memset.S: Reinstate delay slot indentation MIPS: perf: Fix perf with MT counting other threads MIPS: perf: Use correct VPE ID when setting up VPE tracing MIPS: perf: More robustly probe for the presence of per-tc counters MIPS: Probe for MIPS MT perf counters per TC MIPS: mscc: Connect phys to ports on ocelot_pcb123 MIPS: mscc: Add switch to ocelot MIPS: JZ4740: Drop old platform reset code MIPS: qi_lb60: Enable the jz4740-wdt driver MIPS: JZ4780: dts: Fix watchdog node MIPS: JZ4740: dts: Add bindings for the jz4740-wdt driver watchdog: JZ4740: Drop module remove function watchdog: JZ4740: Register a restart handler watchdog: JZ4740: Use devm_* functions watchdog: JZ4740: Disable clock after stopping counter MIPS: VPE: Fix spelling mistake: "uneeded" -> "unneeded" MIPS: Re-use kstrtobool_from_user() MIPS: Convert update_persistent_clock() to update_persistent_clock64() ...

MIPS: ptrace: Fix PTRACE_PEEKUSR requests for 64-bit FGRs

2018-05-24T13:03:14Z

Use 64-bit accesses for 64-bit floating-point general registers with PTRACE_PEEKUSR, removing the truncation of their upper halves in the FR=1 mode, caused by commit bbd426f542cb ("MIPS: Simplify FP context access"), which inadvertently switched them to using 32-bit accesses. The PTRACE_POKEUSR side is fine as it's never been broken and continues using 64-bit accesses. Fixes: bbd426f542cb ("MIPS: Simplify FP context access") Signed-off-by: Maciej W. Rozycki Cc: Ralf Baechle Cc: linux-mips@linux-mips.org Cc: # 3.15+ Patchwork: https://patchwork.linux-mips.org/patch/19334/ Signed-off-by: James Hogan

MIPS: ptrace: Make FPU context layout comments match reality

2018-05-24T12:37:07Z

Correct comments across ptrace(2) handlers about an FPU register context layout discrepancy between MIPS I and later ISAs, which was fixed with `linux-mips.org' (LMO) commit 42533948caac ("Major pile of FP emulator changes."), the fix corrected with LMO commit 849fa7a50dff ("R3k FPU ptrace() handling fixes."), and then broken and fixed over and over again, until last time fixed with commit 80cbfad79096 ("MIPS: Correct MIPS I FP context layout"). NB running the GDB test suite for the relevant ABI/ISA and watching out for regressions is advisable when poking around ptrace(2). Signed-off-by: Maciej W. Rozycki Cc: Ralf Baechle Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/19326/ Signed-off-by: James Hogan

MIPS: Fix ptrace(2) PTRACE_PEEKUSR and PTRACE_POKEUSR accesses to o32 FGRs

2018-05-14T22:54:25Z

Check the TIF_32BIT_FPREGS task setting of the tracee rather than the tracer in determining the layout of floating-point general registers in the floating-point context, correcting access to odd-numbered registers for o32 tracees where the setting disagrees between the two processes. Fixes: 597ce1723e0f ("MIPS: Support for 64-bit FP with O32 binaries") Signed-off-by: Maciej W. Rozycki Cc: Ralf Baechle Cc: linux-mips@linux-mips.org Cc: # 3.14+ Signed-off-by: James Hogan

MIPS: ptrace: Expose FIR register through FP regset

2018-05-14T22:54:25Z

Correct commit 7aeb753b5353 ("MIPS: Implement task_user_regset_view.") and expose the FIR register using the unused 4 bytes at the end of the NT_PRFPREG regset. Without that register included clients cannot use the PTRACE_GETREGSET request to retrieve the complete FPU register set and have to resort to one of the older interfaces, either PTRACE_PEEKUSR or PTRACE_GETFPREGS, to retrieve the missing piece of data. Also the register is irreversibly missing from core dumps. This register is architecturally hardwired and read-only so the write path does not matter. Ignore data supplied on writes then. Fixes: 7aeb753b5353 ("MIPS: Implement task_user_regset_view.") Signed-off-by: James Hogan Signed-off-by: Maciej W. Rozycki Cc: Ralf Baechle Cc: linux-mips@linux-mips.org Cc: # 3.13+ Patchwork: https://patchwork.linux-mips.org/patch/19273/ Signed-off-by: James Hogan

MIPS: Disallow outsized PTRACE_SETREGSET NT_PRFPREG regset accesses

2017-12-12T18:14:12Z

Complement commit c23b3d1a5311 ("MIPS: ptrace: Change GP regset to use correct core dump register layout") and also reject outsized PTRACE_SETREGSET requests to the NT_PRFPREG regset, like with the NT_PRSTATUS regset. Signed-off-by: Maciej W. Rozycki Fixes: c23b3d1a5311 ("MIPS: ptrace: Change GP regset to use correct core dump register layout") Cc: James Hogan Cc: Paul Burton Cc: Alex Smith Cc: Dave Martin Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org Cc: stable@vger.kernel.org # v3.17+ Patchwork: https://patchwork.linux-mips.org/patch/17930/ Signed-off-by: Ralf Baechle

MIPS: Also verify sizeof `elf_fpreg_t' with PTRACE_SETREGSET

2017-12-12T18:13:42Z

Complement commit d614fd58a283 ("mips/ptrace: Preserve previous registers for short regset write") and like with the PTRACE_GETREGSET ptrace(2) request also apply a BUILD_BUG_ON check for the size of the `elf_fpreg_t' type in the PTRACE_SETREGSET request handler. Signed-off-by: Maciej W. Rozycki Fixes: d614fd58a283 ("mips/ptrace: Preserve previous registers for short regset write") Cc: James Hogan Cc: Paul Burton Cc: Alex Smith Cc: Dave Martin Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org Cc: stable@vger.kernel.org # v4.11+ Patchwork: https://patchwork.linux-mips.org/patch/17929/ Signed-off-by: Ralf Baechle