From: Christoph Hellwig <hch@lst.de>
To: x86@kernel.org, Alexei Starovoitov <ast@kernel.org>,
Daniel Borkmann <daniel@iogearbox.net>,
Masami Hiramatsu <mhiramat@kernel.org>,
Linus Torvalds <torvalds@linux-foundation.org>,
Andrew Morton <akpm@linux-foundation.org>
Cc: linux-parisc@vger.kernel.org, linux-um@lists.infradead.org,
netdev@vger.kernel.org, bpf@vger.kernel.org, linux-mm@kvack.org,
linux-kernel@vger.kernel.org
Subject: [PATCH 11/23] bpf: factor out a bpf_trace_copy_string helper
Date: Thu, 21 May 2020 17:22:49 +0200 [thread overview]
Message-ID: <20200521152301.2587579-12-hch@lst.de> (raw)
In-Reply-To: <20200521152301.2587579-1-hch@lst.de>
Split out a helper to do the fault free access to the string pointer
to get it out of a crazy indentation level.
Signed-off-by: Christoph Hellwig <hch@lst.de>
---
kernel/trace/bpf_trace.c | 42 +++++++++++++++++++++++-----------------
1 file changed, 24 insertions(+), 18 deletions(-)
diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c
index f5231ffea85b9..9d4080590f711 100644
--- a/kernel/trace/bpf_trace.c
+++ b/kernel/trace/bpf_trace.c
@@ -321,6 +321,28 @@ static const struct bpf_func_proto *bpf_get_probe_write_proto(void)
return &bpf_probe_write_user_proto;
}
+static void bpf_trace_copy_string(char *buf, void *unsafe_ptr, char fmt_ptype,
+ size_t bufsz)
+{
+ void __user *user_ptr = (__force void __user *)unsafe_ptr;
+
+ buf[0] = 0;
+
+ switch (fmt_ptype) {
+ case 's':
+#ifdef CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
+ strncpy_from_unsafe(buf, unsafe_ptr, bufsz);
+ break;
+#endif
+ case 'k':
+ strncpy_from_kernel_nofault(buf, unsafe_ptr, bufsz);
+ break;
+ case 'u':
+ strncpy_from_user_nofault(buf, user_ptr, bufsz);
+ break;
+ }
+}
+
/*
* Only limited trace_printk() conversion specifiers allowed:
* %d %i %u %x %ld %li %lu %lx %lld %lli %llu %llx %p %pks %pus %s
@@ -403,24 +425,8 @@ BPF_CALL_5(bpf_trace_printk, char *, fmt, u32, fmt_size, u64, arg1,
break;
}
- buf[0] = 0;
- switch (fmt_ptype) {
- case 's':
-#ifdef CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
- strncpy_from_unsafe(buf, unsafe_ptr,
- sizeof(buf));
- break;
-#endif
- case 'k':
- strncpy_from_kernel_nofault(buf, unsafe_ptr,
- sizeof(buf));
- break;
- case 'u':
- strncpy_from_user_nofault(buf,
- (__force void __user *)unsafe_ptr,
- sizeof(buf));
- break;
- }
+ bpf_trace_copy_string(buf, unsafe_ptr, fmt_ptype,
+ sizeof(buf));
goto fmt_next;
}
--
2.26.2
next prev parent reply other threads:[~2020-05-21 15:25 UTC|newest]
Thread overview: 38+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-05-21 15:22 clean up and streamline probe_kernel_* and friends v4 Christoph Hellwig
2020-05-21 15:22 ` [PATCH 01/23] maccess: unexport probe_kernel_write and probe_user_write Christoph Hellwig
2020-05-21 15:22 ` [PATCH 02/23] maccess: remove various unused weak aliases Christoph Hellwig
2020-05-21 15:22 ` [PATCH 03/23] maccess: remove duplicate kerneldoc comments Christoph Hellwig
2020-05-21 15:22 ` [PATCH 04/23] maccess: clarify " Christoph Hellwig
2020-05-21 15:22 ` [PATCH 05/23] maccess: update the top of file comment Christoph Hellwig
2020-05-21 15:22 ` [PATCH 06/23] maccess: rename strncpy_from_unsafe_user to strncpy_from_user_nofault Christoph Hellwig
2020-05-21 15:22 ` [PATCH 07/23] maccess: rename strncpy_from_unsafe_strict to strncpy_from_kernel_nofault Christoph Hellwig
2020-05-21 15:22 ` [PATCH 08/23] maccess: rename strnlen_unsafe_user to strnlen_user_nofault Christoph Hellwig
2020-05-21 15:22 ` [PATCH 09/23] maccess: remove probe_read_common and probe_write_common Christoph Hellwig
2020-05-21 15:22 ` [PATCH 10/23] maccess: unify the probe kernel arch hooks Christoph Hellwig
2020-05-28 0:55 ` Andrew Morton
2020-05-21 15:22 ` Christoph Hellwig [this message]
2020-05-21 22:10 ` [PATCH 11/23] bpf: factor out a bpf_trace_copy_string helper Andrii Nakryiko
2020-05-21 15:22 ` [PATCH 12/23] bpf: handle the compat string in bpf_trace_copy_string better Christoph Hellwig
2020-05-21 22:10 ` Andrii Nakryiko
2020-05-28 2:04 ` Andrew Morton
2020-05-28 2:26 ` Yonghong Song
2020-05-28 4:39 ` Christoph Hellwig
2020-05-28 17:06 ` Yonghong Song
2020-05-21 15:22 ` [PATCH 13/23] bpf: rework the compat kernel probe handling Christoph Hellwig
2020-05-21 22:10 ` Andrii Nakryiko
2020-05-21 15:22 ` [PATCH 14/23] tracing/kprobes: handle mixed kernel/userspace probes better Christoph Hellwig
2020-05-22 0:04 ` Masami Hiramatsu
2020-05-21 15:22 ` [PATCH 15/23] maccess: remove strncpy_from_unsafe Christoph Hellwig
2020-05-21 15:22 ` [PATCH 16/23] maccess: always use strict semantics for probe_kernel_read Christoph Hellwig
2020-05-21 15:22 ` [PATCH 17/23] maccess: move user access routines together Christoph Hellwig
2020-05-21 15:22 ` [PATCH 18/23] maccess: allow architectures to provide kernel probing directly Christoph Hellwig
2020-05-21 15:22 ` [PATCH 19/23] x86: use non-set_fs based maccess routines Christoph Hellwig
2020-05-21 15:22 ` [PATCH 20/23] maccess: rename probe_kernel_{read,write} to copy_{from,to}_kernel_nofault Christoph Hellwig
2020-05-21 15:22 ` [PATCH 21/23] maccess: rename probe_user_{read,write} to copy_{from,to}_user_nofault Christoph Hellwig
2020-05-21 15:23 ` [PATCH 22/23] maccess: rename probe_kernel_address to get_kernel_nofault Christoph Hellwig
2020-05-21 15:23 ` [PATCH 23/23] maccess: return -ERANGE when copy_from_kernel_nofault_allowed fails Christoph Hellwig
2020-05-21 18:03 ` clean up and streamline probe_kernel_* and friends v4 Linus Torvalds
2020-05-22 0:22 ` Masami Hiramatsu
2020-05-25 22:19 ` Andrew Morton
2020-05-26 6:13 ` Christoph Hellwig
2020-05-28 0:36 ` Andrew Morton
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