linux-stable.git/arch/riscv, branch linux-6.3.y

riscv: uprobes: Restore thread.bad_cause

2023-07-11T17:39:48+00:00

[ Upstream commit 58b1294dd1d65bb62f08dddbf418f954210c2057 ]

thread.bad_cause is saved in arch_uprobe_pre_xol(), it should be restored
in arch_uprobe_{post,abort}_xol() accordingly, otherwise the save operation
is meaningless, this change is similar with x86 and powerpc.

Signed-off-by: Tiezhu Yang 
Acked-by: Oleg Nesterov 
Reviewed-by: Guo Ren 
Fixes: 74784081aac8 ("riscv: Add uprobes supported")
Link: https://lore.kernel.org/r/1682214146-3756-1-git-send-email-yangtiezhu@loongson.cn
Signed-off-by: Palmer Dabbelt 
Signed-off-by: Sasha Levin

riscv/mm: Convert to using lock_mm_and_find_vma()

2023-07-01T11:14:45+00:00

commit 7267ef7b0b77f4ed23b7b3c87d8eca7bd9c2d007 upstream.

Signed-off-by: Ben Hutchings 
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman

riscv: Link with '-z norelro'

2023-06-28T09:13:59+00:00

This patch fixes a stable only patch, so it has no direct upstream
equivalent.

After a stable only patch to explicitly handle the '.got' section to
handle an orphan section warning from the linker, certain configurations
error when linking with ld.lld, which enables relro by default:

  ld.lld: error: section: .got is not contiguous with other relro sections

This has come up with other architectures before, such as arm and arm64
in commit 0cda9bc15dfc ("ARM: 9038/1: Link with '-z norelro'") and
commit 3b92fa7485eb ("arm64: link with -z norelro regardless of
CONFIG_RELOCATABLE"). Additionally, '-z norelro' is used unconditionally
for RISC-V upstream after commit 26e7aacb83df ("riscv: Allow to
downgrade paging mode from the command line"), which alluded to this
issue for the same reason. Bring 6.3 in line with mainline and link with
'-z norelro', which resolves the above link failure.

Fixes: e6d1562dd4e9 ("riscv: vmlinux.lds.S: Explicitly handle '.got' section")
Reported-by: kernel test robot 
Closes: https://lore.kernel.org/oe-kbuild-all/202306192231.DJmWr6BX-lkp@intel.com/
Signed-off-by: Nathan Chancellor 
Acked-by: Palmer Dabbelt 
Signed-off-by: Greg Kroah-Hartman

riscv/purgatory: remove PGO flags

2023-06-21T14:02:09+00:00

commit 88ac3bbcf73853880a9b2a65c67e6854390741cc upstream.

If profile-guided optimization is enabled, the purgatory ends up with
multiple .text sections.  This is not supported by kexec and crashes the
system.

Link: https://lkml.kernel.org/r/20230321-kexec_clang16-v7-4-b05c520b7296@chromium.org
Fixes: 930457057abe ("kernel/kexec_file.c: split up __kexec_load_puragory")
Signed-off-by: Ricardo Ribalda 
Acked-by: Palmer Dabbelt 
Cc: 
Cc: Albert Ou 
Cc: Baoquan He 
Cc: Borislav Petkov (AMD) 
Cc: Christophe Leroy 
Cc: Dave Hansen 
Cc: Dave Young 
Cc: Eric W. Biederman 
Cc: "H. Peter Anvin" 
Cc: Ingo Molnar 
Cc: Michael Ellerman 
Cc: Nathan Chancellor 
Cc: Nicholas Piggin 
Cc: Nick Desaulniers 
Cc: Palmer Dabbelt 
Cc: Paul Walmsley 
Cc: Philipp Rudo 
Cc: Ross Zwisler 
Cc: Simon Horman 
Cc: Steven Rostedt (Google) 
Cc: Thomas Gleixner 
Cc: Tom Rix 
Signed-off-by: Andrew Morton 
Signed-off-by: Greg Kroah-Hartman

riscv: fix kprobe __user string arg print fault issue

2023-06-14T09:17:03+00:00

[ Upstream commit 99a670b2069c725a7b50318aa681d9cae8f89325 ]

On riscv qemu platform, when add kprobe event on do_sys_open() to show
filename string arg, it just print fault as follow:

echo 'p:myprobe do_sys_open dfd=$arg1 filename=+0($arg2):string flags=$arg3
mode=$arg4' > kprobe_events

bash-166     [000] ...1.   360.195367: myprobe: (do_sys_open+0x0/0x84)
dfd=0xffffffffffffff9c filename=(fault) flags=0x8241 mode=0x1b6

bash-166     [000] ...1.   360.219369: myprobe: (do_sys_open+0x0/0x84)
dfd=0xffffffffffffff9c filename=(fault) flags=0x8241 mode=0x1b6

bash-191     [000] ...1.   360.378827: myprobe: (do_sys_open+0x0/0x84)
dfd=0xffffffffffffff9c filename=(fault) flags=0x98800 mode=0x0

As riscv do not select ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE,
the +0($arg2) addr is processed as a kernel address though it is a
userspace address, cause the above filename=(fault) print. So select
ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE to avoid the issue, after that the
kprobe trace is ok as below:

bash-166     [000] ...1.    96.767641: myprobe: (do_sys_open+0x0/0x84)
dfd=0xffffffffffffff9c filename="/dev/null" flags=0x8241 mode=0x1b6

bash-166     [000] ...1.    96.793751: myprobe: (do_sys_open+0x0/0x84)
dfd=0xffffffffffffff9c filename="/dev/null" flags=0x8241 mode=0x1b6

bash-177     [000] ...1.    96.962354: myprobe: (do_sys_open+0x0/0x84)
dfd=0xffffffffffffff9c filename="/sys/kernel/debug/tracing/events/kprobes/"
flags=0x98800 mode=0x0

Signed-off-by: Ruan Jinjie 
Acked-by: Björn Töpel 
Fixes: 0ebeea8ca8a4 ("bpf: Restrict bpf_probe_read{, str}() only to archs where they work")
Link: https://lore.kernel.org/r/20230504072910.3742842-1-ruanjinjie@huawei.com
Signed-off-by: Palmer Dabbelt 
Signed-off-by: Sasha Levin

riscv: mm: Ensure prot of VM_WRITE and VM_EXEC must be readable

2023-06-14T09:17:03+00:00

[ Upstream commit 6569fc12e442ea973d96db39e542aa19a7bc3a79 ]

Commit 8aeb7b17f04e ("RISC-V: Make mmap() with PROT_WRITE imply PROT_READ")
allows riscv to use mmap with PROT_WRITE only, and meanwhile mmap with w+x
is also permitted. However, when userspace tries to access this page with
PROT_WRITE|PROT_EXEC, which causes infinite loop at load page fault as
well as it triggers soft lockup. According to riscv privileged spec,
"Writable pages must also be marked readable". The fix to drop the
`PAGE_COPY_READ_EXEC` and then `PAGE_COPY_EXEC` would be just used instead.
This aligns the other arches (i.e arm64) for protection_map.

Fixes: 8aeb7b17f04e ("RISC-V: Make mmap() with PROT_WRITE imply PROT_READ")
Signed-off-by: Hsieh-Tseng Shen 
Reviewed-by: Alexandre Ghiti 
Link: https://lore.kernel.org/r/20230425102828.1616812-1-woodrow.shen@sifive.com
Signed-off-by: Palmer Dabbelt 
Signed-off-by: Sasha Levin

riscv: vmlinux.lds.S: Explicitly handle '.got' section

2023-06-09T08:48:25+00:00

This patch is for linux-6.3.y only, it has no direct mainline
equivalent.

LLVM 17 will now use the GOT for extern weak symbols when using the
medany model, which causes a linker orphan section warning on
linux-6.3.y:

  ld.lld: warning: :(.got) is being placed in '.got'

This is not an issue in mainline because handling of the .got section
was added by commit 39b33072941f ("riscv: Introduce CONFIG_RELOCATABLE")
and further extended by commit 26e7aacb83df ("riscv: Allow to downgrade
paging mode from the command line") in 6.4-rc1. Neither of these changes
are suitable for stable, so add explicit handling of the .got section in
a standalone change to align 6.3 and mainline, which addresses the
warning.

This is only an issue for 6.3 because commit f4b71bff8d85 ("riscv:
select ARCH_WANT_LD_ORPHAN_WARN for !XIP_KERNEL") landed in 6.3-rc1, so
earlier releases will not see this warning because it will not be
enabled.

Closes: https://github.com/ClangBuiltLinux/linux/issues/1865
Link: https://github.com/llvm/llvm-project/commit/a178ba9fbd0a27057dc2fa4cb53c76caa013caac
Signed-off-by: Nathan Chancellor 
Reviewed-by: Conor Dooley 
Signed-off-by: Greg Kroah-Hartman

riscv: perf: Fix callchain parse error with kernel tracepoint events

2023-06-09T08:48:19+00:00

commit 9a7e8ec0d4cc64870ea449b4fce5779b77496cbb upstream.

For RISC-V, when tracing with tracepoint events, the IP and status are
set to 0, preventing the perf code parsing the callchain and resolving
the symbols correctly.

 ./ply 'tracepoint:kmem/kmem_cache_alloc { @[stack]=count(); }'
 @:
 {  }: 1

The fix is to implement perf_arch_fetch_caller_regs for riscv, which
fills several necessary registers used for callchain unwinding,
including epc, sp, s0 and status. It's similar to commit b3eac0265bf6
("arm: perf: Fix callchain parse error with kernel tracepoint events")
and commit 5b09a094f2fb ("arm64: perf: Fix callchain parse error with
kernel tracepoint events").

With this patch, callchain can be parsed correctly as:

 ./ply 'tracepoint:kmem/kmem_cache_alloc { @[stack]=count(); }'
 @:
 {
         __traceiter_kmem_cache_alloc+68
         __traceiter_kmem_cache_alloc+68
         kmem_cache_alloc+354
         __sigqueue_alloc+94
         __send_signal_locked+646
         send_signal_locked+154
         do_send_sig_info+84
         __kill_pgrp_info+130
         kill_pgrp+60
         isig+150
         n_tty_receive_signal_char+36
         n_tty_receive_buf_standard+2214
         n_tty_receive_buf_common+280
         n_tty_receive_buf2+26
         tty_ldisc_receive_buf+34
         tty_port_default_receive_buf+62
         flush_to_ldisc+158
         process_one_work+458
         worker_thread+138
         kthread+178
         riscv_cpufeature_patch_func+832
  }: 1

Signed-off-by: Ism Hong 
Link: https://lore.kernel.org/r/20230601095355.1168910-1-ism.hong@gmail.com
Fixes: 178e9fc47aae ("perf: riscv: preliminary RISC-V support")
Cc: stable@vger.kernel.org
Signed-off-by: Palmer Dabbelt 
Signed-off-by: Greg Kroah-Hartman

riscv: Fix unused variable warning when BUILTIN_DTB is set

2023-06-09T08:47:48+00:00

[ Upstream commit 33d418da6f476b15e4510e0a590062583f63cd36 ]

commit ef69d2559fe9 ("riscv: Move early dtb mapping into the fixmap
region") wrongly moved the #ifndef CONFIG_BUILTIN_DTB surrounding the pa
variable definition in create_fdt_early_page_table(), so move it back to
its right place to quiet the following warning:

../arch/riscv/mm/init.c: In function ‘create_fdt_early_page_table’:
../arch/riscv/mm/init.c:925:12: warning: unused variable ‘pa’ [-Wunused-variable]
  925 |  uintptr_t pa = dtb_pa & ~(PMD_SIZE - 1);

Fixes: ef69d2559fe9 ("riscv: Move early dtb mapping into the fixmap region")
Signed-off-by: Alexandre Ghiti 
Reviewed-by: Conor Dooley 
Link: https://lore.kernel.org/r/20230519131311.391960-1-alexghiti@rivosinc.com
Signed-off-by: Palmer Dabbelt 
Signed-off-by: Sasha Levin

rethook, fprobe: do not trace rethook related functions

2023-05-24T16:30:24+00:00

commit 571a2a50a8fc546145ffd3bf673547e9fe128ed2 upstream.

These functions are already marked as NOKPROBE to prevent recursion and
we have the same reason to blacklist them if rethook is used with fprobe,
since they are beyond the recursion-free region ftrace can guard.

Link: https://lore.kernel.org/all/20230517034510.15639-5-zegao@tencent.com/

Fixes: f3a112c0c40d ("x86,rethook,kprobes: Replace kretprobe with rethook on x86")
Signed-off-by: Ze Gao 
Reviewed-by: Steven Rostedt (Google) 
Acked-by: Masami Hiramatsu (Google) 
Cc: stable@vger.kernel.org
Signed-off-by: Masami Hiramatsu (Google) 
Signed-off-by: Greg Kroah-Hartman