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authorDmitry V. Levin <ldv@altlinux.org>2019-03-29 20:12:21 +0300
committerSteven Rostedt (VMware) <rostedt@goodmis.org>2019-04-04 10:25:31 -0400
commit10a16997db3d99fc02c026cf2c6e6c670acafab0 (patch)
treeb26a45e42c002f64ac9e34bf648b1b1b0d18ee1b /arch/riscv
parentd08e411397cb6fcb3d3fb075c27a41975c99e88f (diff)
downloadlwn-10a16997db3d99fc02c026cf2c6e6c670acafab0.tar.gz
lwn-10a16997db3d99fc02c026cf2c6e6c670acafab0.zip
riscv: Fix syscall_get_arguments() and syscall_set_arguments()
RISC-V syscall arguments are located in orig_a0,a1..a5 fields of struct pt_regs. Due to an off-by-one bug and a bug in pointer arithmetic syscall_get_arguments() was reading s3..s7 fields instead of a1..a5. Likewise, syscall_set_arguments() was writing s3..s7 fields instead of a1..a5. Link: http://lkml.kernel.org/r/20190329171221.GA32456@altlinux.org Fixes: e2c0cdfba7f69 ("RISC-V: User-facing API") Cc: Ingo Molnar <mingo@redhat.com> Cc: Kees Cook <keescook@chromium.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Will Drewry <wad@chromium.org> Cc: Albert Ou <aou@eecs.berkeley.edu> Cc: linux-riscv@lists.infradead.org Cc: stable@vger.kernel.org # v4.15+ Acked-by: Palmer Dabbelt <palmer@sifive.com> Signed-off-by: Dmitry V. Levin <ldv@altlinux.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Diffstat (limited to 'arch/riscv')
-rw-r--r--arch/riscv/include/asm/syscall.h12
1 files changed, 7 insertions, 5 deletions
diff --git a/arch/riscv/include/asm/syscall.h b/arch/riscv/include/asm/syscall.h
index bba3da6ef157..6ea9e1804233 100644
--- a/arch/riscv/include/asm/syscall.h
+++ b/arch/riscv/include/asm/syscall.h
@@ -79,10 +79,11 @@ static inline void syscall_get_arguments(struct task_struct *task,
if (i == 0) {
args[0] = regs->orig_a0;
args++;
- i++;
n--;
+ } else {
+ i--;
}
- memcpy(args, &regs->a1 + i * sizeof(regs->a1), n * sizeof(args[0]));
+ memcpy(args, &regs->a1 + i, n * sizeof(args[0]));
}
static inline void syscall_set_arguments(struct task_struct *task,
@@ -94,10 +95,11 @@ static inline void syscall_set_arguments(struct task_struct *task,
if (i == 0) {
regs->orig_a0 = args[0];
args++;
- i++;
n--;
- }
- memcpy(&regs->a1 + i * sizeof(regs->a1), args, n * sizeof(regs->a0));
+ } else {
+ i--;
+ }
+ memcpy(&regs->a1 + i, args, n * sizeof(regs->a1));
}
static inline int syscall_get_arch(void)