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| author |   Christophe Leroy <christophe.leroy@csgroup.eu> | 2020-07-07 18:32:25 +0000 |
|---|---|---|
| committer |   Michael Ellerman <mpe@ellerman.id.au> | 2020-07-15 12:04:40 +1000 |
| commit | 96032f983ca32ad1d43c73da922dbc7022754c3c (patch) | |
| tree | 38106b01127522d895c83d1af9b51cd2391869a0 | |
| parent | powerpc/signal_32: Simplify loop in PPC64 save_general_regs() (diff) | |
| download | linux-dev-96032f983ca32ad1d43c73da922dbc7022754c3c.tar.xz linux-dev-96032f983ca32ad1d43c73da922dbc7022754c3c.zip | |
powerpc/signal64: Don't opencode page prefaulting
Instead of doing a __get_user() from the first and last location
into a tmp var which won't be used, use fault_in_pages_readable()
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/810bd8840ef990a200f58c9dea9abe767ca02a3a.1594146723.git.christophe.leroy@csgroup.eu
| -rw-r--r-- | arch/powerpc/kernel/signal_64.c | 7 |
1 files changed, 3 insertions, 4 deletions
diff --git a/arch/powerpc/kernel/signal_64.c b/arch/powerpc/kernel/signal_64.c index 97729642f955..bfc939360bad 100644 --- a/arch/powerpc/kernel/signal_64.c +++ b/arch/powerpc/kernel/signal_64.c @@ -21,6 +21,7 @@ #include <linux/ptrace.h> #include <linux/ratelimit.h> #include <linux/syscalls.h> +#include <linux/pagemap.h> #include <asm/sigcontext.h> #include <asm/ucontext.h> @@ -634,7 +635,6 @@ static long setup_trampoline(unsigned int syscall, unsigned int __user *tramp) SYSCALL_DEFINE3(swapcontext, struct ucontext __user *, old_ctx, struct ucontext __user *, new_ctx, long, ctx_size) { - unsigned char tmp; sigset_t set; unsigned long new_msr = 0; int ctx_has_vsx_region = 0; @@ -669,9 +669,8 @@ SYSCALL_DEFINE3(swapcontext, struct ucontext __user *, old_ctx, } if (new_ctx == NULL) return 0; - if (!access_ok(new_ctx, ctx_size) - || __get_user(tmp, (u8 __user *) new_ctx) - || __get_user(tmp, (u8 __user *) new_ctx + ctx_size - 1)) + if (!access_ok(new_ctx, ctx_size) || + fault_in_pages_readable((u8 __user *)new_ctx, ctx_size)) return -EFAULT; /* |