linux.git/arch/riscv, branch v5.12

riscv: keep interrupts disabled for BREAKPOINT exception

2021-04-16T04:32:40+00:00

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 
Reviewed-by: Masami Hiramatsu 
[Palmer: add a comment]
Signed-off-by: Palmer Dabbelt

riscv: kprobes/ftrace: Add recursion protection to the ftrace callback

2021-04-16T04:32:34+00:00

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 
Reviewed-by: Steven Rostedt (VMware) 
Signed-off-by: Palmer Dabbelt

riscv: add do_page_fault and do_trap_break into the kprobes blacklist

2021-04-16T04:32:28+00:00

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 
Reviewed-by: Masami Hiramatsu 
Signed-off-by: Palmer Dabbelt

riscv: Fix spelling mistake "SPARSEMEM" to "SPARSMEM"

2021-04-16T04:32:10+00:00

There is a spelling mistake when SPARSEMEM Kconfig copy.

Fixes: a5406a7ff56e ("riscv: Correct SPARSEMEM configuration")
Cc: stable@vger.kernel.org
Signed-off-by: Kefeng Wang 
Signed-off-by: Palmer Dabbelt

riscv: Make NUMA depend on MMU

2021-04-02T04:37:08+00:00

NUMA is useless when NOMMU, and it leads some build error,
make it depend on MMU.

Reported-by: kernel test robot 
Signed-off-by: Kefeng Wang 
Signed-off-by: Palmer Dabbelt

riscv: remove unneeded semicolon

2021-04-02T04:37:06+00:00

Eliminate the following coccicheck warning:
./arch/riscv/mm/kasan_init.c:219:2-3: Unneeded semicolon

Reported-by: Abaci Robot 
Signed-off-by: Yang Li 
Signed-off-by: Palmer Dabbelt

riscv,entry: fix misaligned base for excp_vect_table

2021-04-02T04:37:05+00:00

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 
Reviewed-by: Anup Patel 
Signed-off-by: Palmer Dabbelt

riscv: evaluate put_user() arg before enabling user access

2021-04-02T04:37:04+00:00

The  header has a problem with put_user(a, ptr) if
the 'a' is not a simple variable, such as a function. This can lead
to the compiler producing code as so:

1:	enable_user_access()
2:	evaluate 'a' into register 'r'
3:	put 'r' to 'ptr'
4:	disable_user_acess()

The issue is that 'a' is now being evaluated with the user memory
protections disabled. So we try and force the evaulation by assigning
'x' to __val at the start, and hoping the compiler barriers in
 enable_user_access() do the job of ordering step 2 before step 1.

This has shown up in a bug where 'a' sleeps and thus schedules out
and loses the SR_SUM flag. This isn't sufficient to fully fix, but
should reduce the window of opportunity. The first instance of this
we found is in scheudle_tail() where the code does:

$ less -N kernel/sched/core.c

4263  if (current->set_child_tid)
4264         put_user(task_pid_vnr(current), current->set_child_tid);

Here, the task_pid_vnr(current) is called within the block that has
enabled the user memory access. This can be made worse with KASAN
which makes task_pid_vnr() a rather large call with plenty of
opportunity to sleep.

Signed-off-by: Ben Dooks 
Reported-by: syzbot+e74b94fe601ab9552d69@syzkaller.appspotmail.com
Suggested-by: Arnd Bergman 

--
Changes since v1:
- fixed formatting and updated the patch description with more info

Changes since v2:
- fixed commenting on __put_user() (schwab@linux-m68k.org)

Change since v3:
- fixed RFC in patch title. Should be ready to merge.

Signed-off-by: Palmer Dabbelt

riscv: Drop const annotation for sp

2021-04-02T04:37:03+00:00

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 
Signed-off-by: Palmer Dabbelt

riscv: Correct SPARSEMEM configuration

2021-03-17T05:15:21+00:00

There are two issues for RV32,
1) if use FLATMEM, it is useless to enable SPARSEMEM_STATIC.
2) if use SPARSMEM, both SPARSEMEM_VMEMMAP and SPARSEMEM_STATIC is enabled.

Fixes: d95f1a542c3d ("RISC-V: Implement sparsemem")
Signed-off-by: Kefeng Wang 
Cc: stable@vger.kernel.org
Signed-off-by: Palmer Dabbelt