diff options
| author | Mathis Salmen <mathis.salmen@matsal.de> | 2023-04-06 12:11:31 +0200 |
|---|---|---|
| committer | Palmer Dabbelt <palmer@rivosinc.com> | 2023-04-11 12:52:27 -0700 |
| commit | 8d736482749f6d350892ef83a7a11d43cd49981e (patch) | |
| tree | 8b4430f45e2dc1a2b4829f34555933d2145a27cd | |
| parent | 4622f159098e098611f393cccf73d52b007e70bc (diff) | |
| download | linux-8d736482749f6d350892ef83a7a11d43cd49981e.tar.gz | |
riscv: add icache flush for nommu sigreturn trampoline
In a NOMMU kernel, sigreturn trampolines are generated on the user
stack by setup_rt_frame. Currently, these trampolines are not instruction
fenced, thus their visibility to ifetch is not guaranteed.
This patch adds a flush_icache_range in setup_rt_frame to fix this
problem.
Signed-off-by: Mathis Salmen <mathis.salmen@matsal.de>
Fixes: 6bd33e1ece52 ("riscv: add nommu support")
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20230406101130.82304-1-mathis.salmen@matsal.de
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
| -rw-r--r-- | arch/riscv/kernel/signal.c | 9 |
1 files changed, 8 insertions, 1 deletions
diff --git a/arch/riscv/kernel/signal.c b/arch/riscv/kernel/signal.c index bfb2afa4135f8..dee66c9290cce 100644 --- a/arch/riscv/kernel/signal.c +++ b/arch/riscv/kernel/signal.c @@ -19,6 +19,7 @@ #include <asm/signal32.h> #include <asm/switch_to.h> #include <asm/csr.h> +#include <asm/cacheflush.h> extern u32 __user_rt_sigreturn[2]; @@ -181,6 +182,7 @@ static int setup_rt_frame(struct ksignal *ksig, sigset_t *set, { struct rt_sigframe __user *frame; long err = 0; + unsigned long __maybe_unused addr; frame = get_sigframe(ksig, regs, sizeof(*frame)); if (!access_ok(frame, sizeof(*frame))) @@ -209,7 +211,12 @@ static int setup_rt_frame(struct ksignal *ksig, sigset_t *set, if (copy_to_user(&frame->sigreturn_code, __user_rt_sigreturn, sizeof(frame->sigreturn_code))) return -EFAULT; - regs->ra = (unsigned long)&frame->sigreturn_code; + + addr = (unsigned long)&frame->sigreturn_code; + /* Make sure the two instructions are pushed to icache. */ + flush_icache_range(addr, addr + sizeof(frame->sigreturn_code)); + + regs->ra = addr; #endif /* CONFIG_MMU */ /* |