kernel.git/arch/arm/kernel/ftrace.c, branch linux-4.19.y

ARM: 9079/1: ftrace: Add MODULE_PLTS support

2021-10-06T13:31:26Z

commit 79f32b221b18c15a98507b101ef4beb52444cc6f upstream Teach ftrace_make_call() and ftrace_make_nop() about PLTs. Teach PLT code about FTRACE and all its callbacks. Otherwise the following might happen: ------------[ cut here ]------------ WARNING: CPU: 14 PID: 2265 at .../arch/arm/kernel/insn.c:14 __arm_gen_branch+0x83/0x8c() ... Hardware name: LSI Axxia AXM55XX [] (unwind_backtrace) from [] (show_stack+0x11/0x14) [] (show_stack) from [] (dump_stack+0x81/0xa8) [] (dump_stack) from [] (warn_slowpath_common+0x69/0x90) [] (warn_slowpath_common) from [] (warn_slowpath_null+0x17/0x1c) [] (warn_slowpath_null) from [] (__arm_gen_branch+0x83/0x8c) [] (__arm_gen_branch) from [] (ftrace_make_nop+0xf/0x24) [] (ftrace_make_nop) from [] (ftrace_process_locs+0x27b/0x3e8) [] (ftrace_process_locs) from [] (load_module+0x11e9/0x1a44) [] (load_module) from [] (SyS_finit_module+0x59/0x84) [] (SyS_finit_module) from [] (ret_fast_syscall+0x1/0x18) ---[ end trace e1b64ced7a89adcc ]--- ------------[ cut here ]------------ WARNING: CPU: 14 PID: 2265 at .../kernel/trace/ftrace.c:1979 ftrace_bug+0x1b1/0x234() ... Hardware name: LSI Axxia AXM55XX [] (unwind_backtrace) from [] (show_stack+0x11/0x14) [] (show_stack) from [] (dump_stack+0x81/0xa8) [] (dump_stack) from [] (warn_slowpath_common+0x69/0x90) [] (warn_slowpath_common) from [] (warn_slowpath_null+0x17/0x1c) [] (warn_slowpath_null) from [] (ftrace_bug+0x1b1/0x234) [] (ftrace_bug) from [] (ftrace_process_locs+0x285/0x3e8) [] (ftrace_process_locs) from [] (load_module+0x11e9/0x1a44) [] (load_module) from [] (SyS_finit_module+0x59/0x84) [] (SyS_finit_module) from [] (ret_fast_syscall+0x1/0x18) ---[ end trace e1b64ced7a89adcd ]--- ftrace failed to modify [] 0xe9ef7006 actual: 02:f0:3b:fa ftrace record flags: 0 (0) expected tramp: c0314265 [florian: resolved merge conflict with struct dyn_arch_ftrace::old_mcount] Signed-off-by: Alexander Sverdlin Signed-off-by: Russell King Signed-off-by: Florian Fainelli Signed-off-by: Greg Kroah-Hartman

ARM: 9078/1: Add warn suppress parameter to arm_gen_branch_link()

2021-10-06T13:31:26Z

commit 890cb057a46d323fd8c77ebecb6485476614cd21 upstream Will be used in the following patch. No functional change. Signed-off-by: Alexander Sverdlin Signed-off-by: Russell King Signed-off-by: Florian Fainelli Signed-off-by: Greg Kroah-Hartman

ARM: function_graph: Simplify with function_graph_enter()

2018-12-05T18:32:09Z

commit f1f5b14afd7cce39e6a9b25c685e1ea34c231096 upstream. The function_graph_enter() function does the work of calling the function graph hook function and the management of the shadow stack, simplifying the work done in the architecture dependent prepare_ftrace_return(). Have ARM use the new code, and remove the shadow stack management as well as having to set up the trace structure. This is needed to prepare for a fix of a design bug on how the curr_ret_stack is used. Cc: Russell King Cc: linux-arm-kernel@lists.infradead.org Cc: stable@kernel.org Fixes: 03274a3ffb449 ("tracing/fgraph: Adjust fgraph depth before calling trace return callback") Reviewed-by: Masami Hiramatsu Signed-off-by: Steven Rostedt (VMware) Signed-off-by: Greg Kroah-Hartman

ARM: 8678/1: ftrace: Adds support for CONFIG_DYNAMIC_FTRACE_WITH_REGS

2017-06-18T21:25:16Z

The DYNAMIC_FTRACE_WITH_REGS configuration makes it possible for a ftrace operation to specify if registers need to saved/restored by the ftrace handler. This is needed by kgraft and possibly other ftrace-based tools, and the ARM architecture is currently lacking this feature. It would also be the first step to support the "Kprobes-on-ftrace" optimization on ARM. This patch introduces a new ftrace handler that stores the registers on the stack before calling the next stage. The registers are restored from the stack before going back to the instrumented function. A side-effect of this patch is to activate the support for ftrace_modify_call() as it defines ARCH_SUPPORTS_FTRACE_OPS for the ARM architecture. Signed-off-by: Abel Vesa Signed-off-by: Russell King

Merge branch 'akpm' (patches from Andrew)

2017-05-09T01:17:56Z

Merge more updates from Andrew Morton: - the rest of MM - various misc things - procfs updates - lib/ updates - checkpatch updates - kdump/kexec updates - add kvmalloc helpers, use them - time helper updates for Y2038 issues. We're almost ready to remove current_fs_time() but that awaits a btrfs merge. - add tracepoints to DAX * emailed patches from Andrew Morton : (114 commits) drivers/staging/ccree/ssi_hash.c: fix build with gcc-4.4.4 selftests/vm: add a test for virtual address range mapping dax: add tracepoint to dax_insert_mapping() dax: add tracepoint to dax_writeback_one() dax: add tracepoints to dax_writeback_mapping_range() dax: add tracepoints to dax_load_hole() dax: add tracepoints to dax_pfn_mkwrite() dax: add tracepoints to dax_iomap_pte_fault() mtd: nand: nandsim: convert to memalloc_noreclaim_*() treewide: convert PF_MEMALLOC manipulations to new helpers mm: introduce memalloc_noreclaim_{save,restore} mm: prevent potential recursive reclaim due to clearing PF_MEMALLOC mm/huge_memory.c: deposit a pgtable for DAX PMD faults when required mm/huge_memory.c: use zap_deposited_table() more time: delete CURRENT_TIME_SEC and CURRENT_TIME gfs2: replace CURRENT_TIME with current_time apparmorfs: replace CURRENT_TIME with current_time() lustre: replace CURRENT_TIME macro fs: ubifs: replace CURRENT_TIME_SEC with current_time fs: ufs: use ktime_get_real_ts64() for birthtime ...

arm: use set_memory.h header

2017-05-09T00:15:13Z

set_memory_* functions have moved to set_memory.h. Switch to this explicitly Link: http://lkml.kernel.org/r/1488920133-27229-3-git-send-email-labbott@redhat.com Signed-off-by: Laura Abbott Acked-by: Russell King Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

ARM: 8668/1: ftrace: Fix dynamic ftrace with DEBUG_RODATA and !FRAME_POINTER

2017-04-20T10:19:43Z

The support for dynamic ftrace with CONFIG_DEBUG_RODATA involves overriding the weak arch_ftrace_update_code() with a variant which makes the kernel text writable around the patching. This override was however added under the CONFIG_OLD_MCOUNT ifdef, and CONFIG_OLD_MCOUNT is only enabled if frame pointers are enabled. This leads to non-functional dynamic ftrace (ftrace triggers a WARN_ON()) when CONFIG_DEBUG_RODATA is enabled and CONFIG_FRAME_POINTER is not. Move the override out of that ifdef and into the CONFIG_DYNAMIC_FTRACE ifdef where it belongs. Fixes: 80d6b0c2eed2a ("ARM: mm: allow text and rodata sections to be read-only") Suggested-by: Nicolai Stange Suggested-by: Rabin Vincent Signed-off-by: Abel Vesa Acked-by: Rabin Vincent Signed-off-by: Russell King

ftrace: Add return address pointer to ftrace_ret_stack

2016-08-24T10:15:14Z

Storing this value will help prevent unwinders from getting out of sync with the function graph tracer ret_stack. Now instead of needing a stateful iterator, they can compare the return address pointer to find the right ret_stack entry. Note that an array of 50 ftrace_ret_stack structs is allocated for every task. So when an arch implements this, it will add either 200 or 400 bytes of memory usage per task (depending on whether it's a 32-bit or 64-bit platform). Signed-off-by: Josh Poimboeuf Acked-by: Steven Rostedt Cc: Andy Lutomirski Cc: Andy Lutomirski Cc: Borislav Petkov Cc: Brian Gerst Cc: Byungchul Park Cc: Denys Vlasenko Cc: Frederic Weisbecker Cc: H. Peter Anvin Cc: Kees Cook Cc: Linus Torvalds Cc: Nilay Vaish Cc: Peter Zijlstra Cc: Thomas Gleixner Link: http://lkml.kernel.org/r/a95cfcc39e8f26b89a430c56926af0bb217bc0a1.1471607358.git.jpoimboe@redhat.com Signed-off-by: Ingo Molnar

ARM: kprobes: enable OPTPROBES for ARM 32

2015-01-13T16:10:17Z

This patch introduce kprobeopt for ARM 32. Limitations: - Currently only kernel compiled with ARM ISA is supported. - Offset between probe point and optinsn slot must not larger than 32MiB. Masami Hiramatsu suggests replacing 2 words, it will make things complex. Futher patch can make such optimization. Kprobe opt on ARM is relatively simpler than kprobe opt on x86 because ARM instruction is always 4 bytes aligned and 4 bytes long. This patch replace probed instruction by a 'b', branch to trampoline code and then calls optimized_callback(). optimized_callback() calls opt_pre_handler() to execute kprobe handler. It also emulate/simulate replaced instruction. When unregistering kprobe, the deferred manner of unoptimizer may leave branch instruction before optimizer is called. Different from x86_64, which only copy the probed insn after optprobe_template_end and reexecute them, this patch call singlestep to emulate/simulate the insn directly. Futher patch can optimize this behavior. Signed-off-by: Wang Nan Acked-by: Masami Hiramatsu Cc: Will Deacon Reviewed-by: Jon Medhurst (Tixy) Signed-off-by: Jon Medhurst

ARM: mm: allow text and rodata sections to be read-only

2014-10-16T21:38:54Z

This introduces CONFIG_DEBUG_RODATA, making kernel text and rodata read-only. Additionally, this splits rodata from text so that rodata can also be NX, which may lead to wasted memory when aligning to SECTION_SIZE. The read-only areas are made writable during ftrace updates and kexec. Signed-off-by: Kees Cook Tested-by: Laura Abbott Acked-by: Nicolas Pitre