kernel.git/arch/riscv/kernel/ftrace.c, branch linux-5.8.y

RISC-V: Take text_mutex in ftrace_init_nop()

2020-10-01T15:36:24Z

[ Upstream commit 66d18dbda8469a944dfec6c49d26d5946efba218 ] Without this we get lockdep failures. They're spurious failures as SMP isn't up when ftrace_init_nop() is called. As far as I can tell the easiest fix is to just take the lock, which also seems like the safest fix. Signed-off-by: Palmer Dabbelt Acked-by: Guo Ren Signed-off-by: Palmer Dabbelt Signed-off-by: Sasha Levin

maccess: rename probe_kernel_{read,write} to copy_{from,to}_kernel_nofault

2020-06-17T17:57:41Z

Better describe what these functions do. Suggested-by: Linus Torvalds Signed-off-by: Christoph Hellwig Signed-off-by: Linus Torvalds

riscv: Use text_mutex instead of patch_lock

2020-05-18T18:38:16Z

We don't need the additional lock protection when patching the text. There are two patching interfaces here: - patch_text: patch code and always synchronize with stop_machine() - patch_text_nosync: patch code without synchronization, it's caller's responsibility to synchronize all CPUs if needed. For the first one, stop_machine() is protected by its own mutex, and also the irq is already disabled here. For the second one, in risc-v real case now, it would be used to ftrace patching the mcount function, since it already running under kstop_machine(), no other thread will run, so we could use text_mutex on ftrace side. Signed-off-by: Zong Li Reviewed-by: Masami Hiramatsu Reviewed-by: Palmer Dabbelt Signed-off-by: Palmer Dabbelt

riscv: Remove the 'riscv_' prefix of function name

2020-05-18T18:38:13Z

Refactor the function name by removing the 'riscv_' prefix, it would be better unless it could mix up with arch-independent functions. Signed-off-by: Zong Li Reviewed-by: Masami Hiramatsu Reviewed-by: Palmer Dabbelt Signed-off-by: Palmer Dabbelt

riscv: patch code by fixmap mapping

2020-03-26T16:24:55Z

On strict kernel memory permission, the ftrace have to change the permission of text for dynamic patching the intructions. Use riscv_patch_text_nosync() to patch code instead of probe_kernel_write. Signed-off-by: Zong Li Signed-off-by: Palmer Dabbelt

riscv: ftrace: correct the condition logic in function graph tracer

2020-01-03T08:56:37Z

The condition should be logical NOT to assign the hook address to parent address. Because the return value 0 of function_graph_enter upon success. Fixes: e949b6db51dc (riscv/function_graph: Simplify with function_graph_enter()) Signed-off-by: Zong Li Reviewed-by: Steven Rostedt (VMware) Cc: stable@vger.kernel.org Signed-off-by: Paul Walmsley

riscv: add missing newlines to printk messages

2019-02-11T23:34:56Z

Add missing newline characters to printk messages. Also replace two pr_warning with the shorter pr_warn, and fix up the tense of one error message while at it. Signed-off-by: Johan Hovold Signed-off-by: Palmer Dabbelt

riscv: remove unused variable in ftrace

2018-12-21T16:11:26Z

Noticed while building kernel-4.20.0-0.rc5.git2.1.fc30 for Fedora 30/RISCV. [..] BUILDSTDERR: arch/riscv/kernel/ftrace.c: In function 'prepare_ftrace_return': BUILDSTDERR: arch/riscv/kernel/ftrace.c:135:6: warning: unused variable 'err' [-Wunused-variable] BUILDSTDERR: int err; BUILDSTDERR: ^~~ [..] Signed-off-by: David Abdurachmanov Fixes: e949b6db51dc1 ("riscv/function_graph: Simplify with function_graph_enter()") Reviewed-by: Olof Johansson Acked-by: Steven Rostedt (VMware) Signed-off-by: Palmer Dabbelt

riscv/function_graph: Simplify with function_graph_enter()

2018-11-28T01:31:16Z

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 riscv 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: Greentime Hu Cc: Alan Kao Cc: stable@kernel.org Fixes: 03274a3ffb449 ("tracing/fgraph: Adjust fgraph depth before calling trace return callback") Reviewed-by: Palmer Dabbelt Reviewed-by: Masami Hiramatsu Signed-off-by: Steven Rostedt (VMware)

riscv/ftrace: Add HAVE_FUNCTION_GRAPH_RET_ADDR_PTR support

2018-04-03T02:59:13Z

In walk_stackframe, the pc now receives the address from calling ftrace_graph_ret_addr instead of manual calculation. Note that the original calculation, pc = frame->ra - 4 is buggy when the instruction at the return address happened to be a compressed inst. But since it is not a critical part of ftrace, it is ignored for now to ease the review process. Cc: Greentime Hu Signed-off-by: Alan Kao Signed-off-by: Palmer Dabbelt