linux.git/arch/riscv/kernel/module.c, branch v6.16

riscv: module: Fix out-of-bounds relocation access

2025-04-14T13:07:07+00:00

The current code allows rel[j] to access one element past the end of the
relocation section. Simplify to num_relocations which is equivalent to
the existing size expression.

Fixes: 080c4324fa5e ("riscv: optimize ELF relocation function in riscv")
Signed-off-by: Samuel Holland 
Reviewed-by: Maxim Kochetkov 
Reviewed-by: Alexandre Ghiti 
Link: https://lore.kernel.org/r/20250409171526.862481-1-samuel.holland@sifive.com
Signed-off-by: Alexandre Ghiti

riscv: Use kvmalloc_array on relocation_hashtable

2025-04-07T08:21:11+00:00

The number of relocations may be a huge value that is unallocatable
by kmalloc. Use kvmalloc instead so that it does not fail.

Fixes: 8fd6c5142395 ("riscv: Add remaining module relocations")
Suggested-by: Clément Léger 
Reviewed-by: Alexandre Ghiti 
Signed-off-by: Will Pierce 
Link: https://lore.kernel.org/r/20250402081426.5197-1-wgpierce17@gmail.com
Signed-off-by: Alexandre Ghiti

riscv: module: remove relocation_head rel_entry member allocation

2025-01-08T18:22:52+00:00

relocation_head's list_head member, rel_entry, doesn't need to be
allocated, its storage can just be part of the allocated relocation_head.
Remove the pointer which allows to get rid of the allocation as well as
an existing memory leak found by Kai Zhang using kmemleak.

Fixes: 8fd6c5142395 ("riscv: Add remaining module relocations")
Reported-by: Kai Zhang 
Signed-off-by: Clément Léger 
Reviewed-by: Andrew Jones 
Reviewed-by: Charlie Jenkins 
Tested-by: Charlie Jenkins 
Link: https://lore.kernel.org/r/20241128081636.3620468-1-cleger@rivosinc.com
Signed-off-by: Palmer Dabbelt

riscv: Use LIST_HEAD() to simplify code

2024-09-17T13:26:07+00:00

list_head can be initialized automatically with LIST_HEAD()
instead of calling INIT_LIST_HEAD().

Signed-off-by: Jinjie Ruan 
Tested-by: Charlie Jenkins 
Reviewed-by: Charlie Jenkins 
Link: https://lore.kernel.org/r/20240904013344.2026738-1-ruanjinjie@huawei.com
Signed-off-by: Palmer Dabbelt

arch: make execmem setup available regardless of CONFIG_MODULES

2024-05-14T07:31:44+00:00

execmem does not depend on modules, on the contrary modules use
execmem.

To make execmem available when CONFIG_MODULES=n, for instance for
kprobes, split execmem_params initialization out from
arch/*/kernel/module.c and compile it when CONFIG_EXECMEM=y

Signed-off-by: Mike Rapoport (IBM) 
Reviewed-by: Philippe Mathieu-Daudé 
Signed-off-by: Luis Chamberlain

riscv: extend execmem_params for generated code allocations

2024-05-14T07:31:43+00:00

The memory allocations for kprobes and BPF on RISC-V are not placed in
the modules area and these custom allocations are implemented with
overrides of alloc_insn_page() and  bpf_jit_alloc_exec().

Define MODULES_VADDR and MODULES_END as VMALLOC_START and VMALLOC_END for
32 bit and slightly reorder execmem_params initialization to support both
32 and 64 bit variants, define EXECMEM_KPROBES and EXECMEM_BPF ranges in
riscv::execmem_params and drop overrides of alloc_insn_page() and
bpf_jit_alloc_exec().

Signed-off-by: Mike Rapoport (IBM) 
Reviewed-by: Alexandre Ghiti 
Signed-off-by: Luis Chamberlain

mm/execmem, arch: convert simple overrides of module_alloc to execmem

2024-05-14T07:31:43+00:00

Several architectures override module_alloc() only to define address
range for code allocations different than VMALLOC address space.

Provide a generic implementation in execmem that uses the parameters for
address space ranges, required alignment and page protections provided
by architectures.

The architectures must fill execmem_info structure and implement
execmem_arch_setup() that returns a pointer to that structure. This way the
execmem initialization won't be called from every architecture, but rather
from a central place, namely a core_initcall() in execmem.

The execmem provides execmem_alloc() API that wraps __vmalloc_node_range()
with the parameters defined by the architectures.  If an architecture does
not implement execmem_arch_setup(), execmem_alloc() will fall back to
module_alloc().

Signed-off-by: Mike Rapoport (IBM) 
Acked-by: Song Liu 
Reviewed-by: Masami Hiramatsu (Google) 
Signed-off-by: Luis Chamberlain

riscv: optimize ELF relocation function in riscv

2024-01-18T02:21:10+00:00

The patch can optimize the running times of insmod command by modify ELF
relocation function.
In the 5.10 and latest kernel, when install the riscv ELF drivers which
contains multiple symbol table items to be relocated, kernel takes a lot
of time to execute the relocation. For example, we install a 3+MB driver
need 180+s.
We focus on the riscv architecture handle R_RISCV_HI20 and R_RISCV_LO20
type items relocation function in the arch\riscv\kernel\module.c and
find that there are two-loops in the function. If we modify the begin
number in the second for-loops iteration, we could save significant time
for installation. We install the same 3+MB driver could just need 2s.

Signed-off-by: Amma Lee 
Signed-off-by: Maxim Kochetkov 
Reviewed-by: Charlie Jenkins 
Link: https://lore.kernel.org/r/20231214063906.13612-1-fido_max@inbox.ru
Signed-off-by: Palmer Dabbelt

Merge patch series "riscv: modules: Fix module loading error handling"

2024-01-11T15:36:25+00:00

Charlie Jenkins  says:

When modules are loaded while there is not ample allocatable memory,
there was previously not proper error handling. This series fixes a
use-after-free error and a different issue that caused a non graceful
exit after memory was not properly allocated.

* b4-shazam-merge:
  riscv: Fix relocation_hashtable size
  riscv: Correctly free relocation hashtable on error
  riscv: Fix module loading free order

Link: https://lore.kernel.org/r/20240104-module_loading_fix-v3-0-a71f8de6ce0f@rivosinc.com
Signed-off-by: Palmer Dabbelt

riscv: Fix relocation_hashtable size

2024-01-10T14:48:13+00:00

A second dereference is needed to get the accurate size of the
relocation_hashtable.

Signed-off-by: Charlie Jenkins 
Fixes: d8792a5734b0 ("riscv: Safely remove entries from relocation list")
Reported-by: kernel test robot 
Reported-by: Julia Lawall 
Closes: https://lore.kernel.org/r/202312120044.wTI1Uyaa-lkp@intel.com/
Reviewed-by: Dan Carpenter 
Link: https://lore.kernel.org/r/20240104-module_loading_fix-v3-3-a71f8de6ce0f@rivosinc.com
Signed-off-by: Palmer Dabbelt