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The execution of sys_read end up hitting a BUG_ON() in __find_get_block
after installing kprobe at sys_read, the BUG message like the following:
[ 65.708663] ------------[ cut here ]------------
[ 65.709987] kernel BUG at fs/buffer.c:1251!
[ 65.711283] Kernel BUG [#1]
[ 65.712032] Modules linked in:
[ 65.712925] CPU: 0 PID: 51 Comm: sh Not tainted 5.12.0-rc4 #1
[ 65.714407] Hardware name: riscv-virtio,qemu (DT)
[ 65.715696] epc : __find_get_block+0x218/0x2c8
[ 65.716835] ra : __getblk_gfp+0x1c/0x4a
[ 65.717831] epc : ffffffe00019f11e ra : ffffffe00019f56a sp : ffffffe002437930
[ 65.719553] gp : ffffffe000f06030 tp : ffffffe0015abc00 t0 : ffffffe00191e038
[ 65.721290] t1 : ffffffe00191e038 t2 : 000000000000000a s0 : ffffffe002437960
[ 65.723051] s1 : ffffffe00160ad00 a0 : ffffffe00160ad00 a1 : 000000000000012a
[ 65.724772] a2 : 0000000000000400 a3 : 0000000000000008 a4 : 0000000000000040
[ 65.726545] a5 : 0000000000000000 a6 : ffffffe00191e000 a7 : 0000000000000000
[ 65.728308] s2 : 000000000000012a s3 : 0000000000000400 s4 : 0000000000000008
[ 65.730049] s5 : 000000000000006c s6 : ffffffe00240f800 s7 : ffffffe000f080a8
[ 65.731802] s8 : 0000000000000001 s9 : 000000000000012a s10: 0000000000000008
[ 65.733516] s11: 0000000000000008 t3 : 00000000000003ff t4 : 000000000000000f
[ 65.734434] t5 : 00000000000003ff t6 : 0000000000040000
[ 65.734613] status: 0000000000000100 badaddr: 0000000000000000 cause: 0000000000000003
[ 65.734901] Call Trace:
[ 65.735076] [<ffffffe00019f11e>] __find_get_block+0x218/0x2c8
[ 65.735417] [<ffffffe00020017a>] __ext4_get_inode_loc+0xb2/0x2f6
[ 65.735618] [<ffffffe000201b6c>] ext4_get_inode_loc+0x3a/0x8a
[ 65.735802] [<ffffffe000203380>] ext4_reserve_inode_write+0x2e/0x8c
[ 65.735999] [<ffffffe00020357a>] __ext4_mark_inode_dirty+0x4c/0x18e
[ 65.736208] [<ffffffe000206bb0>] ext4_dirty_inode+0x46/0x66
[ 65.736387] [<ffffffe000192914>] __mark_inode_dirty+0x12c/0x3da
[ 65.736576] [<ffffffe000180dd2>] touch_atime+0x146/0x150
[ 65.736748] [<ffffffe00010d762>] filemap_read+0x234/0x246
[ 65.736920] [<ffffffe00010d834>] generic_file_read_iter+0xc0/0x114
[ 65.737114] [<ffffffe0001f5d7a>] ext4_file_read_iter+0x42/0xea
[ 65.737310] [<ffffffe000163f2c>] new_sync_read+0xe2/0x15a
[ 65.737483] [<ffffffe000165814>] vfs_read+0xca/0xf2
[ 65.737641] [<ffffffe000165bae>] ksys_read+0x5e/0xc8
[ 65.737816] [<ffffffe000165c26>] sys_read+0xe/0x16
[ 65.737973] [<ffffffe000003972>] ret_from_syscall+0x0/0x2
[ 65.738858] ---[ end trace fe93f985456c935d ]---
A simple reproducer looks like:
echo 'p:myprobe sys_read fd=%a0 buf=%a1 count=%a2' > /sys/kernel/debug/tracing/kprobe_events
echo 1 > /sys/kernel/debug/tracing/events/kprobes/myprobe/enable
cat /sys/kernel/debug/tracing/trace
Here's what happens to hit that BUG_ON():
1) After installing kprobe at entry of sys_read, the first instruction
is replaced by 'ebreak' instruction on riscv64 platform.
2) Once kernel reach the 'ebreak' instruction at the entry of sys_read,
it trap into the riscv breakpoint handler, where it do something to
setup for coming single-step of origin instruction, including backup
the 'sstatus' in pt_regs, followed by disable interrupt during single
stepping via clear 'SIE' bit of 'sstatus' in pt_regs.
3) Then kernel restore to the instruction slot contains two instructions,
one is original instruction at entry of sys_read, the other is 'ebreak'.
Here it trigger a 'Instruction page fault' exception (value at 'scause'
is '0xc'), if PF is not filled into PageTabe for that slot yet.
4) Again kernel trap into page fault exception handler, where it choose
different policy according to the state of running kprobe. Because
afte 2) the state is KPROBE_HIT_SS, so kernel reset the current kprobe
and 'pc' points back to the probe address.
5) Because 'epc' point back to 'ebreak' instrution at sys_read probe,
kernel trap into breakpoint handler again, and repeat the operations
at 2), however 'sstatus' without 'SIE' is keep at 4), it cause the
real 'sstatus' saved at 2) is overwritten by the one withou 'SIE'.
6) When kernel cross the probe the 'sstatus' CSR restore with value
without 'SIE', and reach __find_get_block where it requires the
interrupt must be enabled.
Fix this is very trivial, just restore the value of 'sstatus' in pt_regs
with backup one at 2) when the instruction being single stepped cause a
page fault.
Fixes: c22b0bcb1dd02 ("riscv: Add kprobes supported")
Signed-off-by: Liao Chang <liaochang1@huawei.com>
Cc: stable@vger.kernel.org
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
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The core code manages the executable permissions of code regions of
modules explicitly, it is not necessary to create the module vmalloc
regions with RWX permissions. Create them with RW- permissions instead.
Signed-off-by: Jisheng Zhang <jszhang@kernel.org>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
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Allocate PAGE_KERNEL_READ_EXEC(read only, executable) page for kprobes
insn page. This is to prepare for STRICT_MODULE_RWX.
Signed-off-by: Jisheng Zhang <jszhang@kernel.org>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
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Constify the sbi_ipi_ops so that it will be placed in the .rodata
section. This will cause attempts to modify it to fail when strict
page permissions are in place.
Signed-off-by: Jisheng Zhang <jszhang@kernel.org>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
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Constify the sys_call_table so that it will be placed in the .rodata
section. This will cause attempts to modify the table to fail when
strict page permissions are in place.
Signed-off-by: Jisheng Zhang <jszhang@kernel.org>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
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All of these are never modified after init, so they can be
__ro_after_init.
Signed-off-by: Jisheng Zhang <jszhang@kernel.org>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
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They are not needed after booting, so mark them as __init to move them
to the __init section.
Signed-off-by: Jisheng Zhang <jszhang@kernel.org>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
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This is a preparatory patch for relocatable kernel and sv48 support.
The kernel used to be linked at PAGE_OFFSET address therefore we could use
the linear mapping for the kernel mapping. But the relocated kernel base
address will be different from PAGE_OFFSET and since in the linear mapping,
two different virtual addresses cannot point to the same physical address,
the kernel mapping needs to lie outside the linear mapping so that we don't
have to copy it at the same physical offset.
The kernel mapping is moved to the last 2GB of the address space, BPF
is now always after the kernel and modules use the 2GB memory range right
before the kernel, so BPF and modules regions do not overlap. KASLR
implementation will simply have to move the kernel in the last 2GB range
and just take care of leaving enough space for BPF.
In addition, by moving the kernel to the end of the address space, both
sv39 and sv48 kernels will be exactly the same without needing to be
relocated at runtime.
Suggested-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Alexandre Ghiti <alex@ghiti.fr>
[Palmer: Squash the STRICT_RWX fix, and a !MMU fix]
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
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Prior to clang 13.0.0, the RISC-V name for the mcount symbol was
"mcount", which differs from the GCC version of "_mcount", which results
in the following errors:
riscv64-linux-gnu-ld: init/main.o: in function `__traceiter_initcall_level':
main.c:(.text+0xe): undefined reference to `mcount'
riscv64-linux-gnu-ld: init/main.o: in function `__traceiter_initcall_start':
main.c:(.text+0x4e): undefined reference to `mcount'
riscv64-linux-gnu-ld: init/main.o: in function `__traceiter_initcall_finish':
main.c:(.text+0x92): undefined reference to `mcount'
riscv64-linux-gnu-ld: init/main.o: in function `.LBB32_28':
main.c:(.text+0x30c): undefined reference to `mcount'
riscv64-linux-gnu-ld: init/main.o: in function `free_initmem':
main.c:(.text+0x54c): undefined reference to `mcount'
This has been corrected in https://reviews.llvm.org/D98881 but the
minimum supported clang version is 10.0.1. To avoid build errors and to
gain a working function tracer, adjust the name of the mcount symbol for
older versions of clang in mount.S and recordmcount.pl.
Link: https://github.com/ClangBuiltLinux/linux/issues/1331
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
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Currently, the VDSO is being linked through $(CC). This does not match
how the rest of the kernel links objects, which is through the $(LD)
variable.
When linking with clang, there are a couple of warnings about flags that
will not be used during the link:
clang-12: warning: argument unused during compilation: '-no-pie' [-Wunused-command-line-argument]
clang-12: warning: argument unused during compilation: '-pg' [-Wunused-command-line-argument]
'-no-pie' was added in commit 85602bea297f ("RISC-V: build vdso-dummy.o
with -no-pie") to override '-pie' getting added to the ld command from
distribution versions of GCC that enable PIE by default. It is
technically no longer needed after commit c2c81bb2f691 ("RISC-V: Fix the
VDSO symbol generaton for binutils-2.35+"), which removed vdso-dummy.o
in favor of generating vdso-syms.S from vdso.so with $(NM) but this also
resolves the issue in case it ever comes back due to having full control
over the $(LD) command. '-pg' is for function tracing, it is not used
during linking as clang states.
These flags could be removed/filtered to fix the warnings but it is
easier to just match the rest of the kernel and use $(LD) directly for
linking. See commits
fe00e50b2db8 ("ARM: 8858/1: vdso: use $(LD) instead of $(CC) to link VDSO")
691efbedc60d ("arm64: vdso: use $(LD) instead of $(CC) to link VDSO")
2ff906994b6c ("MIPS: VDSO: Use $(LD) instead of $(CC) to link VDSO")
2b2a25845d53 ("s390/vdso: Use $(LD) instead of $(CC) to link vDSO")
for more information.
The flags are converted to linker flags and '--eh-frame-hdr' is added to
match what is added by GCC implicitly, which can be seen by adding '-v'
to GCC's invocation.
Additionally, since this area is being modified, use the $(OBJCOPY)
variable instead of an open coded $(CROSS_COMPILE)objcopy so that the
user's choice of objcopy binary is respected.
Link: https://github.com/ClangBuiltLinux/linux/issues/803
Link: https://github.com/ClangBuiltLinux/linux/issues/970
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Reviewed-by: Fangrui Song <maskray@google.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
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Add sign extension to the $badaddr before addressing the instruction page
fault and instruction access fault to workaround the issue "cip-453".
To avoid affecting the existing code sequence, this patch will creates two
trampolines to add sign extension to the $badaddr. By the "alternative"
mechanism, these two trampolines will replace the original exception
handler of instruction page fault and instruction access fault in the
excp_vect_table. In this case, only the specific SiFive CPU core jumps to
the do_page_fault and do_trap_insn_fault through these two trampolines.
Other CPUs are not affected.
Signed-off-by: Vincent Chen <vincent.chen@sifive.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
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Introduce the "alternative" mechanism from ARM64 and x86 to apply the CPU
vendors' errata solution at runtime. The main purpose of this patch is
to provide a framework. Therefore, the implementation is quite basic for
now so that some scenarios could not use this schemei, such as patching
code to a module, relocating the patching code and heterogeneous CPU
topology.
Users could use the macro ALTERNATIVE to apply an errata to the existing
code flow. In the macro ALTERNATIVE, users need to specify the manufacturer
information(vendorid, archid, and impid) for this errata. Therefore, kernel
will know this errata is suitable for which CPU core. During the booting
procedure, kernel will select the errata required by the CPU core and then
patch it. It means that the kernel only applies the errata to the specified
CPU core. In this case, the vendor's errata does not affect each other at
runtime. The above patching procedure only occurs during the booting phase,
so we only take the overhead of the "alternative" mechanism once.
This "alternative" mechanism is enabled by default to ensure that all
required errata will be applied. However, users can disable this feature by
the Kconfig "CONFIG_RISCV_ERRATA_ALTERNATIVE".
Signed-off-by: Vincent Chen <vincent.chen@sifive.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
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Add 3 wrapper functions to get vendor id, architecture id and implement id
from M-mode
Signed-off-by: Vincent Chen <vincent.chen@sifive.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
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Current riscv's kprobe handlers are run with both preemption and
interrupt enabled, this violates kprobe requirements. Fix this issue
by keeping interrupts disabled for BREAKPOINT exception.
Fixes: c22b0bcb1dd0 ("riscv: Add kprobes supported")
Cc: stable@vger.kernel.org
Signed-off-by: Jisheng Zhang <jszhang@kernel.org>
Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org>
[Palmer: add a comment]
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
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Currently, the riscv's kprobes(powerred by ftrace) handler is
preemptible. Futher check indicates we miss something similar as the
commit c536aa1c5b17 ("kprobes/ftrace: Add recursion protection to the
ftrace callback"), so do similar modifications as the commit does.
Fixes: 829adda597fe ("riscv: Add KPROBES_ON_FTRACE supported")
Cc: stable@vger.kernel.org
Signed-off-by: Jisheng Zhang <jszhang@kernel.org>
Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
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These two functions are used to implement the kprobes feature so they
can't be kprobed.
Fixes: c22b0bcb1dd0 ("riscv: Add kprobes supported")
Cc: stable@vger.kernel.org
Signed-off-by: Jisheng Zhang <jszhang@kernel.org>
Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
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In RV64, the size of each entry in excp_vect_table is 8 bytes. If the
base of the table is not 8-byte aligned, loading an entry in the table
will raise a misaligned exception. Although such exception will be
handled by opensbi/bbl, this still causes performance degradation.
Signed-off-by: Zihao Yu <yuzihao@ict.ac.cn>
Reviewed-by: Anup Patel <anup@brainfault.org>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
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The const annotation should not be used for 'sp', or it will
become read only and lead to bad stack output.
Fixes: dec822771b01 ("riscv: stacktrace: Move register keyword to beginning of declaration")
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
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The sbi_init() already prints SBI version before detecting
various SBI extensions so we don't need to print SBI version
for all detected SBI extensions.
Signed-off-by: Anup Patel <anup.patel@wdc.com>
Reviewed-by: Atish Patra <atish.patra@wdc.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
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init_resources() allocates an array of resources, based on the current
total number of memory regions and reserved memory regions. However,
allocating this array using memblock_alloc() might increase the number
of reserved memory regions. If that happens, populating the array later
based on the new number of regions will cause out-of-bounds writes
beyond the end of the allocated array.
Fix this by allocating one more entry, which may or may not be used.
Fixes: 797f0375dd2ef5cd ("RISC-V: Do not allocate memblock while iterating reserved memblocks")
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Reviewed-by: Atish Patra <atish.patra@wdc.com>
Cc: stable@vger.kernel.org
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
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There is a spelling mistake in a comment, fix it.
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
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When percpu-timers are stopped by deep power saving mode, we
need system timer help to broadcast IPI_TIMER.
This is first introduced by broken x86 hardware, where the local apic
timer stops in C3 state. But many other architectures(powerpc, mips,
arm, hexagon, openrisc, sh) have supported the infrastructure to
deal with Power Management issues.
Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
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Use BUG_ON instead of a if condition followed by BUG.
Generated by: scripts/coccinelle/misc/bugon.cocci
Fixes: c22b0bcb1dd0 ("riscv: Add kprobes supported")
CC: Guo Ren <guoren@linux.alibaba.com>
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: kernel test robot <lkp@intel.com>
Signed-off-by: Julia Lawall <julia.lawall@inria.fr>
Reviewed-by: Pekka Enberg <penberg@kernel.org>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
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Use ftrace_get_regs() helper call to get pt_regs from ftrace_regs struct,
this makes the code simpler.
Signed-off-by: Nanyong Sun <sunnanyong@huawei.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
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Include header file to fix the following W=1 compilation warning:
arch/riscv/kernel/process.c:78:6: warning: no previous prototype for ‘show_regs’ [-Wmissing-prototypes]
78 | void show_regs(struct pt_regs *regs)
| ^~~~~~~~~
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Nanyong Sun <sunnanyong@huawei.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
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Building riscv syscall table with W=1 throws the warning as
following pattern:
arch/riscv/kernel/syscall_table.c:14:36: warning: initialized field overwritten [-Woverride-init]
14 | #define __SYSCALL(nr, call) [nr] = (call),
| ^
./include/uapi/asm-generic/unistd.h:29:37: note: in expansion of macro ‘__SYSCALL’
29 | #define __SC_COMP(_nr, _sys, _comp) __SYSCALL(_nr, _sys)
| ^~~~~~~~~
./include/uapi/asm-generic/unistd.h:34:1: note: in expansion of macro ‘__SC_COMP’
34 | __SC_COMP(__NR_io_setup, sys_io_setup, compat_sys_io_setup)
| ^~~~~~~~~
arch/riscv/kernel/syscall_table.c:14:36: note: (near initialization for ‘sys_call_table[0]’)
14 | #define __SYSCALL(nr, call) [nr] = (call),
| ^
./include/uapi/asm-generic/unistd.h:29:37: note: in expansion of macro ‘__SYSCALL’
29 | #define __SC_COMP(_nr, _sys, _comp) __SYSCALL(_nr, _sys)
| ^~~~~~~~~
./include/uapi/asm-generic/unistd.h:34:1: note: in expansion of macro ‘__SC_COMP’
34 | __SC_COMP(__NR_io_setup, sys_io_setup, compat_sys_io_setup)
| ^~~~~~~~~
arch/riscv/kernel/syscall_table.c:14:36: warning: initialized field overwritten [-Woverride-init]
...
Since we intentionally build the syscall tables this way,ignore the warning.
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Nanyong Sun <sunnanyong@huawei.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
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Fix the following W=1 compilation warning:
arch/riscv/kernel/time.c:16:13: warning: no previous prototype for ‘time_init’ [-Wmissing-prototypes]
16 | void __init time_init(void)
| ^~~~~~~~~
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Nanyong Sun <sunnanyong@huawei.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
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Fix the comment of __sbi_set_timer_v01, the function name in comment
is missing '__'
Signed-off-by: Nanyong Sun <sunnanyong@huawei.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
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Fix all W=1 compilation warnings:'no previous prototype for' in arch/riscv/kernel/traps.c:
arch/riscv/kernel/traps.c:96:15: warning: no previous prototype for ‘do_trap_unknown’ [-Wmissing-prototypes]
96 | DO_ERROR_INFO(do_trap_unknown,
| ^~~~~~~~~~~~~~~
arch/riscv/kernel/traps.c:91:27: note: in definition of macro ‘DO_ERROR_INFO’
91 | asmlinkage __visible void name(struct pt_regs *regs) \
| ^~~~
arch/riscv/kernel/traps.c:98:15: warning: no previous prototype for ‘do_trap_insn_misaligned’ [-Wmissing-prototypes]
98 | DO_ERROR_INFO(do_trap_insn_misaligned,
| ^~~~~~~~~~~~~~~~~~~~~~~
arch/riscv/kernel/traps.c:91:27: note: in definition of macro ‘DO_ERROR_INFO’
91 | asmlinkage __visible void name(struct pt_regs *regs) \
| ^~~~
arch/riscv/kernel/traps.c:100:15: warning: no previous prototype for ‘do_trap_insn_fault’ [-Wmissing-prototypes]
...
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Nanyong Sun <sunnanyong@huawei.com>
[Palmer: fix checkpatch warnings]
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
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Pull io_uring thread rewrite from Jens Axboe:
"This converts the io-wq workers to be forked off the tasks in question
instead of being kernel threads that assume various bits of the
original task identity.
This kills > 400 lines of code from io_uring/io-wq, and it's the worst
part of the code. We've had several bugs in this area, and the worry
is always that we could be missing some pieces for file types doing
unusual things (recent /dev/tty example comes to mind, userfaultfd
reads installing file descriptors is another fun one... - both of
which need special handling, and I bet it's not the last weird oddity
we'll find).
With these identical workers, we can have full confidence that we're
never missing anything. That, in itself, is a huge win. Outside of
that, it's also more efficient since we're not wasting space and code
on tracking state, or switching between different states.
I'm sure we're going to find little things to patch up after this
series, but testing has been pretty thorough, from the usual
regression suite to production. Any issue that may crop up should be
manageable.
There's also a nice series of further reductions we can do on top of
this, but I wanted to get the meat of it out sooner rather than later.
The general worry here isn't that it's fundamentally broken. Most of
the little issues we've found over the last week have been related to
just changes in how thread startup/exit is done, since that's the main
difference between using kthreads and these kinds of threads. In fact,
if all goes according to plan, I want to get this into the 5.10 and
5.11 stable branches as well.
That said, the changes outside of io_uring/io-wq are:
- arch setup, simple one-liner to each arch copy_thread()
implementation.
- Removal of net and proc restrictions for io_uring, they are no
longer needed or useful"
* tag 'io_uring-worker.v3-2021-02-25' of git://git.kernel.dk/linux-block: (30 commits)
io-wq: remove now unused IO_WQ_BIT_ERROR
io_uring: fix SQPOLL thread handling over exec
io-wq: improve manager/worker handling over exec
io_uring: ensure SQPOLL startup is triggered before error shutdown
io-wq: make buffered file write hashed work map per-ctx
io-wq: fix race around io_worker grabbing
io-wq: fix races around manager/worker creation and task exit
io_uring: ensure io-wq context is always destroyed for tasks
arch: ensure parisc/powerpc handle PF_IO_WORKER in copy_thread()
io_uring: cleanup ->user usage
io-wq: remove nr_process accounting
io_uring: flag new native workers with IORING_FEAT_NATIVE_WORKERS
net: remove cmsg restriction from io_uring based send/recvmsg calls
Revert "proc: don't allow async path resolution of /proc/self components"
Revert "proc: don't allow async path resolution of /proc/thread-self components"
io_uring: move SQPOLL thread io-wq forked worker
io-wq: make io_wq_fork_thread() available to other users
io-wq: only remove worker from free_list, if it was there
io_uring: remove io_identity
io_uring: remove any grabbing of context
...
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux
Pull RISC-V updates from Palmer Dabbelt:
"A handful of new RISC-V related patches for this merge window:
- A check to ensure drivers are properly using uaccess. This isn't
manifesting with any of the drivers I'm currently using, but may
catch errors in new drivers.
- Some preliminary support for the FU740, along with the HiFive
Unleashed it will appear on.
- NUMA support for RISC-V, which involves making the arm64 code
generic.
- Support for kasan on the vmalloc region.
- A handful of new drivers for the Kendryte K210, along with the DT
plumbing required to boot on a handful of K210-based boards.
- Support for allocating ASIDs.
- Preliminary support for kernels larger than 128MiB.
- Various other improvements to our KASAN support, including the
utilization of huge pages when allocating the KASAN regions.
We may have already found a bug with the KASAN_VMALLOC code, but it's
passing my tests. There's a fix in the works, but that will probably
miss the merge window.
* tag 'riscv-for-linus-5.12-mw0' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux: (75 commits)
riscv: Improve kasan population by using hugepages when possible
riscv: Improve kasan population function
riscv: Use KASAN_SHADOW_INIT define for kasan memory initialization
riscv: Improve kasan definitions
riscv: Get rid of MAX_EARLY_MAPPING_SIZE
soc: canaan: Sort the Makefile alphabetically
riscv: Disable KSAN_SANITIZE for vDSO
riscv: Remove unnecessary declaration
riscv: Add Canaan Kendryte K210 SD card defconfig
riscv: Update Canaan Kendryte K210 defconfig
riscv: Add Kendryte KD233 board device tree
riscv: Add SiPeed MAIXDUINO board device tree
riscv: Add SiPeed MAIX GO board device tree
riscv: Add SiPeed MAIX DOCK board device tree
riscv: Add SiPeed MAIX BiT board device tree
riscv: Update Canaan Kendryte K210 device tree
dt-bindings: add resets property to dw-apb-timer
dt-bindings: fix sifive gpio properties
dt-bindings: update sifive uart compatible string
dt-bindings: update sifive clint compatible string
...
|
|
We use the generic C VDSO implementations of a handful of clock-related
functions. When kasan is enabled this results in asan stub calls that
are unlikely to be resolved by userspace, this just disables KASAN
when building the VDSO.
Verified the fix on a kernel with KASAN enabled using vDSO selftests.
Link: https://lore.kernel.org/lkml/CACT4Y+ZNJBnkKHXUf=tm_yuowvZvHwN=0rmJ=7J+xFd+9r_6pQ@mail.gmail.com/
Tested-by: Tobias Klauser <tklauser@distanz.ch>
Signed-off-by: Tobias Klauser <tklauser@distanz.ch>
Tested-by: Dmitry Vyukov <dvyukov@google.com>
[Palmer: commit text]
Fixes: ad5d1122b82f ("riscv: use vDSO common flow to reduce the latency of the time-related functions")
Cc: stable@vger.kernel.org
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
|
|
SBI v0.2 functions can return an error code from SBI implementation.
We are already processing the SBI error code and coverts it to the Linux
error code.
Propagate to the error code to the caller as well. As of now, kvm is the
only user of these error codes.
Signed-off-by: Atish Patra <atish.patra@wdc.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
|
|
PF_IO_WORKER are kernel threads too, but they aren't PF_KTHREAD in the
sense that we don't assign ->set_child_tid with our own structure. Just
ensure that every arch sets up the PF_IO_WORKER threads like kthreads
in the arch implementation of copy_thread().
Signed-off-by: Jens Axboe <axboe@kernel.dk>
|
|
Neither of these are actually correct: the instruction stream is defined
(for versions of the ISA manual newer than 2.2) as a stream of 16-bit
little-endian parcels, which is different than just being little-endian.
In theory we should represent this as a type, but we don't have any
concrete plans for the big endian stuff so it doesn't seem worth the
time -- we've got variants of this all over the place.
Instead I'm just dropping the unnecessary type conversion, which is a
NOP on LE systems but causes an sparse error as the types are all mixed
up.
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
Acked-by: Guo Ren <guoren@kernel.org>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
|
|
"kerne" -> "kernel"
Signed-off-by: WenZhang <zhangwen@yulong.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
|
|
Sometimes, especially in a production system we may not want to
use a "smart bootloader" like u-boot to load kernel, ramdisk and
device tree from a filesystem on eMMC, but rather load the kernel
from a NAND partition and just run it as soon as we can, and in
this case it is convenient to have device tree compiled into the
kernel binary. Since this case is not limited to MMU-less systems,
let's support it for these which have MMU enabled too.
While at it, provide __dtb_start as a parameter to setup_vm() in
BUILTIN_DTB case, so we don't have to duplicate BUILTIN_DTB specific
processing in MMU-enabled and MMU-disabled versions of setup_vm().
Signed-off-by: Vitaly Wool <vitaly.wool@konsulko.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
|
|
.init section permission should only updated to non-execute if
STRICT_KERNEL_RWX is enabled. Otherwise, this will lead to a kernel hang.
Fixes: 19a00869028f ("RISC-V: Protect all kernel sections including init early")
Cc: stable@vger.kernel.org
Suggested-by: Geert Uytterhoeven <geert@linux-m68k.org>
Reported-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Atish Patra <atish.patra@wdc.com>
Reviewed-by: Atish Patra <atish.patra@wdc.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
|
|
Currently, resource tree allocates memory blocks while iterating on the
list. It leads to following kernel warning because memblock allocation
also invokes memory block reservation API.
[ 0.000000] ------------[ cut here ]------------
[ 0.000000] WARNING: CPU: 0 PID: 0 at kernel/resource.c:795
__insert_resource+0x8e/0xd0
[ 0.000000] Modules linked in:
[ 0.000000] CPU: 0 PID: 0 Comm: swapper Not tainted
5.10.0-00022-ge20097fb37e2-dirty #549
[ 0.000000] epc: c00125c2 ra : c001262c sp : c1c01f50
[ 0.000000] gp : c1d456e0 tp : c1c0a980 t0 : ffffcf20
[ 0.000000] t1 : 00000000 t2 : 00000000 s0 : c1c01f60
[ 0.000000] s1 : ffffcf00 a0 : ffffff00 a1 : c1c0c0c4
[ 0.000000] a2 : 80c12b15 a3 : 80402000 a4 : 80402000
[ 0.000000] a5 : c1c0c0c4 a6 : 80c12b15 a7 : f5faf600
[ 0.000000] s2 : c1c0c0c4 s3 : c1c0e000 s4 : c1009a80
[ 0.000000] s5 : c1c0c000 s6 : c1d48000 s7 : c1613b4c
[ 0.000000] s8 : 00000fff s9 : 80000200 s10: c1613b40
[ 0.000000] s11: 00000000 t3 : c1d4a000 t4 : ffffffff
This is also unnecessary as we can pre-compute the total memblocks required
for each memory region and allocate it before the loop. It save precious
boot time not going through memblock allocation code every time.
Fixes: 00ab027a3b82 ("RISC-V: Add kernel image sections to the resource tree")
Reviewed-by: Anup Patel <anup@brainfault.org>
Tested-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Atish Patra <atish.patra@wdc.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
|
|
Using global sp_in_global directly to fix the following warning,
arch/riscv/kernel/stacktrace.c:31:3: warning: ‘register’ is not at beginning of declaration [-Wold-style-declaration]
31 | const register unsigned long current_sp = sp_in_global;
| ^~~~~
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
|
|
When a function doesn't have a callee, then it will not
push ra into the stack, such as lkdtm_BUG() function,
addi sp,sp,-16
sd s0,8(sp)
addi s0,sp,16
ebreak
The struct stackframe use {fp,ra} to get information from
stack, if walk_stackframe() with pr_regs, we will obtain
wrong value and bad stacktrace,
[<ffffffe00066c56c>] lkdtm_BUG+0x6/0x8
---[ end trace 18da3fbdf08e25d5 ]---
Correct the next fp and pc, after that, full stacktrace
shown as expects,
[<ffffffe00066c56c>] lkdtm_BUG+0x6/0x8
[<ffffffe0008b24a4>] lkdtm_do_action+0x14/0x1c
[<ffffffe00066c372>] direct_entry+0xc0/0x10a
[<ffffffe000439f86>] full_proxy_write+0x42/0x6a
[<ffffffe000309626>] vfs_write+0x7e/0x214
[<ffffffe00030992a>] ksys_write+0x98/0xc0
[<ffffffe000309960>] sys_write+0xe/0x16
[<ffffffe0002014bc>] ret_from_syscall+0x0/0x2
---[ end trace 61917f3d9a9fadcd ]---
Signed-off-by: Chen Huang <chenhuang5@huawei.com>
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
|
|
Show the function symbols of epc and ra to improve the
readability of crash reports, and align the printing
formats about the raw epc value.
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
|
|
Like commit 1149aad10b1e ("arm64: Add dump_backtrace() in show_regs"),
dump the stack in riscv show_regs as common code expects.
Reviewed-by: Atish Patra <atish.patra@wdc.com>
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
|
|
This enables the use of per-task stack canary values if GCC has
support for emitting the stack canary reference relative to the
value of tp, which holds the task struct pointer in the riscv
kernel.
After compare arm64 and x86 implementations, seems arm64's is more
flexible and readable. The key point is how gcc get the offset of
stack_canary from gs/el0_sp.
x86: Use a fix offset from gs, not flexible.
struct fixed_percpu_data {
/*
* GCC hardcodes the stack canary as %gs:40. Since the
* irq_stack is the object at %gs:0, we reserve the bottom
* 48 bytes of the irq stack for the canary.
*/
char gs_base[40]; // :(
unsigned long stack_canary;
};
arm64: Use -mstack-protector-guard-offset & guard-reg
gcc options:
-mstack-protector-guard=sysreg
-mstack-protector-guard-reg=sp_el0
-mstack-protector-guard-offset=xxx
riscv: Use -mstack-protector-guard-offset & guard-reg
gcc options:
-mstack-protector-guard=tls
-mstack-protector-guard-reg=tp
-mstack-protector-guard-offset=xxx
GCC's implementation has been merged:
commit c931e8d5a96463427040b0d11f9c4352ac22b2b0
Author: Cooper Qu <cooper.qu@linux.alibaba.com>
Date: Mon Jul 13 16:15:08 2020 +0800
RISC-V: Add support for TLS stack protector canary access
In the end, these codes are inserted by gcc before return:
* 0xffffffe00020b396 <+120>: ld a5,1008(tp) # 0x3f0
* 0xffffffe00020b39a <+124>: xor a5,a5,a4
* 0xffffffe00020b39c <+126>: mv a0,s5
* 0xffffffe00020b39e <+128>: bnez a5,0xffffffe00020b61c <_do_fork+766>
0xffffffe00020b3a2 <+132>: ld ra,136(sp)
0xffffffe00020b3a4 <+134>: ld s0,128(sp)
0xffffffe00020b3a6 <+136>: ld s1,120(sp)
0xffffffe00020b3a8 <+138>: ld s2,112(sp)
0xffffffe00020b3aa <+140>: ld s3,104(sp)
0xffffffe00020b3ac <+142>: ld s4,96(sp)
0xffffffe00020b3ae <+144>: ld s5,88(sp)
0xffffffe00020b3b0 <+146>: ld s6,80(sp)
0xffffffe00020b3b2 <+148>: ld s7,72(sp)
0xffffffe00020b3b4 <+150>: addi sp,sp,144
0xffffffe00020b3b6 <+152>: ret
...
* 0xffffffe00020b61c <+766>: auipc ra,0x7f8
* 0xffffffe00020b620 <+770>: jalr -1764(ra) # 0xffffffe000a02f38 <__stack_chk_fail>
Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
Signed-off-by: Cooper Qu <cooper.qu@linux.alibaba.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
|
|
This patch adds support for uprobes on riscv architecture.
Just like kprobe, it support single-step and simulate instructions.
Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
Reviewed-by: Pekka Enberg <penberg@kernel.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Palmer Dabbelt <palmerdabbelt@google.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
|
|
This patch adds support for kprobes on ftrace call sites to avoids
much of the overhead with regular kprobes. Try it with simple
steps:
echo 'p:myprobe sys_clone a0=%a0 a1=%a1 stack_val=+4($stack)' > /sys/kernel/de
bug/tracing/kprobe_events
echo 1 > /sys/kernel/debug/tracing/events/kprobes/enable
cat /sys/kernel/debug/tracing/trace
tracer: nop
entries-in-buffer/entries-written: 1/1 #P:1
_-----=> irqs-off
/ _----=> need-resched
| / _---=> hardirq/softirq
|| / _--=> preempt-depth
||| / delay
TASK-PID CPU# |||| TIMESTAMP FUNCTION
| | | |||| | |
sh-92 [000] .... 369.899962: myprobe: (sys_clone+0x0/0x28) a0=0x1200011 a1=0x0 stack_val=0x201c20ffffffe0
cat /sys/kernel/debug/kprobes/list
ffffffe00020b584 k sys_clone+0x0 [FTRACE]
^^^^^^
Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
|
|
This patch enables "kprobe & kretprobe" to work with ftrace
interface. It utilized software breakpoint as single-step
mechanism.
Some instructions which can't be single-step executed must be
simulated in kernel execution slot, such as: branch, jal, auipc,
la ...
Some instructions should be rejected for probing and we use a
blacklist to filter, such as: ecall, ebreak, ...
We use ebreak & c.ebreak to replace origin instruction and the
kprobe handler prepares an executable memory slot for out-of-line
execution with a copy of the original instruction being probed.
In execution slot we add ebreak behind original instruction to
simulate a single-setp mechanism.
The patch is based on packi's work [1] and csky's work [2].
- The kprobes_trampoline.S is all from packi's patch
- The single-step mechanism is new designed for riscv without hw
single-step trap
- The simulation codes are from csky
- Frankly, all codes refer to other archs' implementation
[1] https://lore.kernel.org/linux-riscv/20181113195804.22825-1-me@packi.ch/
[2] https://lore.kernel.org/linux-csky/20200403044150.20562-9-guoren@kernel.org/
Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
Co-developed-by: Patrick Stählin <me@packi.ch>
Signed-off-by: Patrick Stählin <me@packi.ch>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Tested-by: Zong Li <zong.li@sifive.com>
Reviewed-by: Pekka Enberg <penberg@kernel.org>
Cc: Patrick Stählin <me@packi.ch>
Cc: Palmer Dabbelt <palmerdabbelt@google.com>
Cc: Björn Töpel <bjorn.topel@gmail.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
|
|
This patch changes the current detour mechanism of dynamic ftrace
which has been discussed during LPC 2020 RISCV-MC [1].
Before the patch, we used mcount for detour:
<funca>:
addi sp,sp,-16
sd ra,8(sp)
sd s0,0(sp)
addi s0,sp,16
mv a5,ra
mv a0,a5
auipc ra,0x0 -> nop
jalr -296(ra) <_mcount@plt> ->nop
...
After the patch, we use nop call site area for detour:
<funca>:
nop -> REG_S ra, -SZREG(sp)
nop -> auipc ra, 0x?
nop -> jalr ?(ra)
nop -> REG_L ra, -SZREG(sp)
...
The mcount mechanism is mixed with gcc function prologue which is
not very clear. The patchable function entry just put 16 bytes nop
before the front of the function prologue which could be filled
with a separated detour mechanism.
[1] https://www.linuxplumbersconf.org/event/7/contributions/807/
Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
|
|
Just like arm64, we can't trace the function in the patch_text path.
Here is the bug log:
[ 45.234334] Unable to handle kernel paging request at virtual address ffffffd38ae80900
[ 45.242313] Oops [#1]
[ 45.244600] Modules linked in:
[ 45.247678] CPU: 0 PID: 11 Comm: migration/0 Not tainted 5.9.0-00025-g9b7db83-dirty #215
[ 45.255797] epc: ffffffe00021689a ra : ffffffe00021718e sp : ffffffe01afabb58
[ 45.262955] gp : ffffffe00136afa0 tp : ffffffe01af94d00 t0 : 0000000000000002
[ 45.270200] t1 : 0000000000000000 t2 : 0000000000000001 s0 : ffffffe01afabc08
[ 45.277443] s1 : ffffffe0013718a8 a0 : 0000000000000000 a1 : ffffffe01afabba8
[ 45.284686] a2 : 0000000000000000 a3 : 0000000000000000 a4 : c4c16ad38ae80900
[ 45.291929] a5 : 0000000000000000 a6 : 0000000000000000 a7 : 0000000052464e43
[ 45.299173] s2 : 0000000000000001 s3 : ffffffe000206a60 s4 : ffffffe000206a60
[ 45.306415] s5 : 00000000000009ec s6 : ffffffe0013718a8 s7 : c4c16ad38ae80900
[ 45.313658] s8 : 0000000000000004 s9 : 0000000000000001 s10: 0000000000000001
[ 45.320902] s11: 0000000000000003 t3 : 0000000000000001 t4 : ffffffffd192fe79
[ 45.328144] t5 : ffffffffb8f80000 t6 : 0000000000040000
[ 45.333472] status: 0000000200000100 badaddr: ffffffd38ae80900 cause: 000000000000000f
[ 45.341514] ---[ end trace d95102172248fdcf ]---
[ 45.346176] note: migration/0[11] exited with preempt_count 1
(gdb) x /2i $pc
=> 0xffffffe00021689a <__do_proc_dointvec+196>: sd zero,0(s7)
0xffffffe00021689e <__do_proc_dointvec+200>: li s11,0
(gdb) bt
0 __do_proc_dointvec (tbl_data=0x0, table=0xffffffe01afabba8,
write=0, buffer=0x0, lenp=0x7bf897061f9a0800, ppos=0x4, conv=0x0,
data=0x52464e43) at kernel/sysctl.c:581
1 0xffffffe00021718e in do_proc_dointvec (data=<optimized out>,
conv=<optimized out>, ppos=<optimized out>, lenp=<optimized out>,
buffer=<optimized out>, write=<optimized out>, table=<optimized out>)
at kernel/sysctl.c:964
2 proc_dointvec_minmax (ppos=<optimized out>, lenp=<optimized out>,
buffer=<optimized out>, write=<optimized out>, table=<optimized out>)
at kernel/sysctl.c:964
3 proc_do_static_key (table=<optimized out>, write=1, buffer=0x0,
lenp=0x0, ppos=0x7bf897061f9a0800) at kernel/sysctl.c:1643
4 0xffffffe000206792 in ftrace_make_call (rec=<optimized out>,
addr=<optimized out>) at arch/riscv/kernel/ftrace.c:109
5 0xffffffe0002c9c04 in __ftrace_replace_code
(rec=0xffffffe01ae40c30, enable=3) at kernel/trace/ftrace.c:2503
6 0xffffffe0002ca0b2 in ftrace_replace_code (mod_flags=<optimized
out>) at kernel/trace/ftrace.c:2530
7 0xffffffe0002ca26a in ftrace_modify_all_code (command=5) at
kernel/trace/ftrace.c:2677
8 0xffffffe0002ca30e in __ftrace_modify_code (data=<optimized out>)
at kernel/trace/ftrace.c:2703
9 0xffffffe0002c13b0 in multi_cpu_stop (data=0x0) at kernel/stop_machine.c:224
10 0xffffffe0002c0fde in cpu_stopper_thread (cpu=<optimized out>) at
kernel/stop_machine.c:491
11 0xffffffe0002343de in smpboot_thread_fn (data=0x0) at kernel/smpboot.c:165
12 0xffffffe00022f8b4 in kthread (_create=0xffffffe01af0c040) at
kernel/kthread.c:292
13 0xffffffe000201fac in handle_exception () at arch/riscv/kernel/entry.S:236
0xffffffe00020678a <+114>: auipc ra,0xffffe
0xffffffe00020678e <+118>: jalr -118(ra) # 0xffffffe000204714 <patch_text_nosync>
0xffffffe000206792 <+122>: snez a0,a0
(gdb) disassemble patch_text_nosync
Dump of assembler code for function patch_text_nosync:
0xffffffe000204714 <+0>: addi sp,sp,-32
0xffffffe000204716 <+2>: sd s0,16(sp)
0xffffffe000204718 <+4>: sd ra,24(sp)
0xffffffe00020471a <+6>: addi s0,sp,32
0xffffffe00020471c <+8>: auipc ra,0x0
0xffffffe000204720 <+12>: jalr -384(ra) # 0xffffffe00020459c <patch_insn_write>
0xffffffe000204724 <+16>: beqz a0,0xffffffe00020472e <patch_text_nosync+26>
0xffffffe000204726 <+18>: ld ra,24(sp)
0xffffffe000204728 <+20>: ld s0,16(sp)
0xffffffe00020472a <+22>: addi sp,sp,32
0xffffffe00020472c <+24>: ret
0xffffffe00020472e <+26>: sd a0,-24(s0)
0xffffffe000204732 <+30>: auipc ra,0x4
0xffffffe000204736 <+34>: jalr -1464(ra) # 0xffffffe00020817a <flush_icache_all>
0xffffffe00020473a <+38>: ld a0,-24(s0)
0xffffffe00020473e <+42>: ld ra,24(sp)
0xffffffe000204740 <+44>: ld s0,16(sp)
0xffffffe000204742 <+46>: addi sp,sp,32
0xffffffe000204744 <+48>: ret
(gdb) disassemble flush_icache_all-4
Dump of assembler code for function flush_icache_all:
0xffffffe00020817a <+0>: addi sp,sp,-8
0xffffffe00020817c <+2>: sd ra,0(sp)
0xffffffe00020817e <+4>: auipc ra,0xfffff
0xffffffe000208182 <+8>: jalr -1822(ra) # 0xffffffe000206a60 <ftrace_caller>
0xffffffe000208186 <+12>: ld ra,0(sp)
0xffffffe000208188 <+14>: addi sp,sp,8
0xffffffe00020818a <+0>: addi sp,sp,-16
0xffffffe00020818c <+2>: sd s0,0(sp)
0xffffffe00020818e <+4>: sd ra,8(sp)
0xffffffe000208190 <+6>: addi s0,sp,16
0xffffffe000208192 <+8>: li a0,0
0xffffffe000208194 <+10>: auipc ra,0xfffff
0xffffffe000208198 <+14>: jalr -410(ra) # 0xffffffe000206ffa <sbi_remote_fence_i>
0xffffffe00020819c <+18>: ld s0,0(sp)
0xffffffe00020819e <+20>: ld ra,8(sp)
0xffffffe0002081a0 <+22>: addi sp,sp,16
0xffffffe0002081a2 <+24>: ret
(gdb) frame 5
(rec=0xffffffe01ae40c30, enable=3) at kernel/trace/ftrace.c:2503
2503 return ftrace_make_call(rec, ftrace_addr);
(gdb) p /x rec->ip
$2 = 0xffffffe00020817a -> flush_icache_all !
When we modified flush_icache_all's patchable-entry with ftrace_caller:
- Insert ftrace_caller at flush_icache_all prologue.
- Call flush_icache_all to sync I/Dcache, but flush_icache_all is
just we modified by half.
Link: https://lore.kernel.org/linux-riscv/CAJF2gTT=oDWesWe0JVWvTpGi60-gpbNhYLdFWN_5EbyeqoEDdw@mail.gmail.com/T/#t
Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
Reviewed-by: Atish Patra <atish.patra@wdc.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
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We must use $(CC_FLAGS_FTRACE) instead of directly using -pg. It
will cause -fpatchable-function-entry error.
Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
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