[PATCH v14 00/12] powerpc: Switch to CONFIG_THREAD_INFO_IN_TASK

From: Christophe Leroy
Date: Thu Jan 24 2019 - 11:19:33 EST


The purpose of this serie is to activate CONFIG_THREAD_INFO_IN_TASK which
moves the thread_info into task_struct.

Moving thread_info into task_struct has the following advantages:
- It protects thread_info from corruption in the case of stack
overflows.
- Its address is harder to determine if stack addresses are
leaked, making a number of attacks more difficult.

Added Mark Rutland in copy as he did the work on arm64 and may have recommendations for us.

Changes in v14 (ie since v13):
- Added in front a fixup patch which conflicts with this serie
- Added a patch for using try_get_task_stack()/put_task_stack() in stack walkers.
- Fixed compilation failure in the preparation patch (by moving the modification
of klp_init_thread_info() to the following patch)

Changes since v12:
- Patch 1: Taken comment from Mike (re-introduced the 'panic' in case memblock allocation fails in setup_64.c
- Patch 1: Added alloc_stack() function in setup_32.c to also panic in case of allocation failure.

Changes since v11:
- Rebased on 81775f5563fa ("Automatic merge of branches 'master', 'next' and 'fixes' into merge")
- Added a first patch to change memblock allocs to functions returning virtual addrs. This removes
the memset() which were the only remaining stuff in irq_ctx_init() and exc_lvl_ctx_init() at the end.
- dropping irq_ctx_init() and exc_lvl_ctx_init() in patch 5 (powerpc: Activate CONFIG_THREAD_INFO_IN_TASK)
- A few cosmetic changes in commit log and code.

Changes since v10:
- Rebased on 21622a0d2023 ("Automatic merge of branches 'master', 'next' and 'fixes' into merge")
==> Fixed conflict in setup_32.S

Changes since v9:
- Rebased on 183cbf93be88 ("Automatic merge of branches 'master', 'next' and 'fixes' into merge")
==> Fixed conflict on xmon

Changes since v8:
- Rebased on e589b79e40d9 ("Automatic merge of branches 'master', 'next' and 'fixes' into merge")
==> Main impact was conflicts due to commit 9a8dd708d547 ("memblock: rename memblock_alloc{_nid,_try_nid} to memblock_phys_alloc*")

Changes since v7:
- Rebased on fb6c6ce7907d ("Automatic merge of branches 'master', 'next' and 'fixes' into merge")

Changes since v6:
- Fixed validate_sp() to exclude NULL sp in 'regain entire stack space' patch (early crash with CONFIG_KMEMLEAK)

Changes since v5:
- Fixed livepatch_sp setup by using end_of_stack() instead of hardcoding
- Fixed PPC_BPF_LOAD_CPU() macro

Changes since v4:
- Fixed a build failure on 32bits SMP when include/generated/asm-offsets.h is not
already existing, was due to spaces instead of a tab in the Makefile

Changes since RFC v3: (based on Nick's review)
- Renamed task_size.h to task_size_user64.h to better relate to what it contains.
- Handling of the isolation of thread_info cpu field inside CONFIG_SMP #ifdefs moved to a separate patch.
- Removed CURRENT_THREAD_INFO macro completely.
- Added a guard in asm/smp.h to avoid build failure before _TASK_CPU is defined.
- Added a patch at the end to rename 'tp' pointers to 'sp' pointers
- Renamed 'tp' into 'sp' pointers in preparation patch when relevant
- Fixed a few commit logs
- Fixed checkpatch report.

Changes since RFC v2:
- Removed the modification of names in asm-offsets
- Created a rule in arch/powerpc/Makefile to append the offset of current->cpu in CFLAGS
- Modified asm/smp.h to use the offset set in CFLAGS
- Squashed the renaming of THREAD_INFO to TASK_STACK in the preparation patch
- Moved the modification of current_pt_regs in the patch activating CONFIG_THREAD_INFO_IN_TASK

Changes since RFC v1:
- Removed the first patch which was modifying header inclusion order in timer
- Modified some names in asm-offsets to avoid conflicts when including asm-offsets in C files
- Modified asm/smp.h to avoid having to include linux/sched.h (using asm-offsets instead)
- Moved some changes from the activation patch to the preparation patch.

Christophe Leroy (12):
powerpc/32: Fix CONFIG_VIRT_CPU_ACCOUNTING_NATIVE for 40x/booke
powerpc/irq: use memblock functions returning virtual address
book3s/64: avoid circular header inclusion in mmu-hash.h
powerpc: Only use task_struct 'cpu' field on SMP
powerpc: prep stack walkers for THREAD_INFO_IN_TASK
powerpc: Prepare for moving thread_info into task_struct
powerpc: Activate CONFIG_THREAD_INFO_IN_TASK
powerpc: regain entire stack space
powerpc: 'current_set' is now a table of task_struct pointers
powerpc/32: Remove CURRENT_THREAD_INFO and rename TI_CPU
powerpc/64: Remove CURRENT_THREAD_INFO
powerpc: clean stack pointers naming

arch/powerpc/Kconfig | 1 +
arch/powerpc/Makefile | 7 ++
arch/powerpc/include/asm/asm-prototypes.h | 4 +-
arch/powerpc/include/asm/book3s/64/mmu-hash.h | 2 +-
arch/powerpc/include/asm/exception-64s.h | 4 +-
arch/powerpc/include/asm/irq.h | 18 ++--
arch/powerpc/include/asm/livepatch.h | 6 +-
arch/powerpc/include/asm/processor.h | 39 +--------
arch/powerpc/include/asm/ptrace.h | 2 +-
arch/powerpc/include/asm/reg.h | 2 +-
arch/powerpc/include/asm/smp.h | 17 +++-
arch/powerpc/include/asm/task_size_user64.h | 42 +++++++++
arch/powerpc/include/asm/thread_info.h | 19 -----
arch/powerpc/kernel/asm-offsets.c | 10 ++-
arch/powerpc/kernel/entry_32.S | 75 ++++++----------
arch/powerpc/kernel/entry_64.S | 12 +--
arch/powerpc/kernel/epapr_hcalls.S | 5 +-
arch/powerpc/kernel/exceptions-64e.S | 13 +--
arch/powerpc/kernel/exceptions-64s.S | 2 +-
arch/powerpc/kernel/head_32.S | 14 +--
arch/powerpc/kernel/head_40x.S | 4 +-
arch/powerpc/kernel/head_44x.S | 8 +-
arch/powerpc/kernel/head_64.S | 1 +
arch/powerpc/kernel/head_8xx.S | 2 +-
arch/powerpc/kernel/head_booke.h | 12 +--
arch/powerpc/kernel/head_fsl_booke.S | 16 ++--
arch/powerpc/kernel/idle_6xx.S | 8 +-
arch/powerpc/kernel/idle_book3e.S | 2 +-
arch/powerpc/kernel/idle_e500.S | 8 +-
arch/powerpc/kernel/idle_power4.S | 2 +-
arch/powerpc/kernel/irq.c | 114 +++----------------------
arch/powerpc/kernel/kgdb.c | 28 ------
arch/powerpc/kernel/machine_kexec_64.c | 6 +-
arch/powerpc/kernel/misc_32.S | 17 ++--
arch/powerpc/kernel/process.c | 63 ++++++++------
arch/powerpc/kernel/setup-common.c | 2 +-
arch/powerpc/kernel/setup_32.c | 25 +++---
arch/powerpc/kernel/setup_64.c | 51 +++--------
arch/powerpc/kernel/smp.c | 16 ++--
arch/powerpc/kernel/stacktrace.c | 29 ++++++-
arch/powerpc/kernel/trace/ftrace_64_mprofile.S | 6 +-
arch/powerpc/kvm/book3s_hv_hmi.c | 1 +
arch/powerpc/mm/hash_low_32.S | 14 ++-
arch/powerpc/net/bpf_jit32.h | 5 +-
arch/powerpc/sysdev/6xx-suspend.S | 5 +-
arch/powerpc/xmon/xmon.c | 2 +-
46 files changed, 300 insertions(+), 441 deletions(-)
create mode 100644 arch/powerpc/include/asm/task_size_user64.h

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2.13.3