diff options
| author | Christoph Hellwig <hch@lst.de> | 2020-08-12 03:33:47 +0200 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2020-08-12 19:57:59 +0200 |
| commit | 3d13f313ce4c34c524ccc37986fe77172f601ff3 (patch) | |
| tree | fd71a87be80c03601ab0e3be425fe45da116b5ba /kernel/events | |
| parent | uaccess: remove segment_eq (diff) | |
| download | linux-3d13f313ce4c34c524ccc37986fe77172f601ff3.tar.xz linux-3d13f313ce4c34c524ccc37986fe77172f601ff3.zip | |
uaccess: add force_uaccess_{begin,end} helpers
Add helpers to wrap the get_fs/set_fs magic for undoing any damange done
by set_fs(KERNEL_DS). There is no real functional benefit, but this
documents the intent of these calls better, and will allow stubbing the
functions out easily for kernels builds that do not allow address space
overrides in the future.
[hch@lst.de: drop two incorrect hunks, fix a commit log typo]
Link: http://lkml.kernel.org/r/20200714105505.935079-6-hch@lst.de
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Greentime Hu <green.hu@gmail.com>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Nick Hu <nickhu@andestech.com>
Cc: Vincent Chen <deanbo422@gmail.com>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Link: http://lkml.kernel.org/r/20200710135706.537715-6-hch@lst.de
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'kernel/events')
| -rw-r--r-- | kernel/events/callchain.c | 5 | ||||
| -rw-r--r-- | kernel/events/core.c | 5 |
2 files changed, 4 insertions, 6 deletions
diff --git a/kernel/events/callchain.c b/kernel/events/callchain.c index c6ce894e4ce9..58cbe357fb2b 100644 --- a/kernel/events/callchain.c +++ b/kernel/events/callchain.c @@ -217,10 +217,9 @@ get_perf_callchain(struct pt_regs *regs, u32 init_nr, bool kernel, bool user, if (add_mark) perf_callchain_store_context(&ctx, PERF_CONTEXT_USER); - fs = get_fs(); - set_fs(USER_DS); + fs = force_uaccess_begin(); perf_callchain_user(&ctx, regs); - set_fs(fs); + force_uaccess_end(fs); } } diff --git a/kernel/events/core.c b/kernel/events/core.c index d1f0a7e5b182..6961333ebad5 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -6453,10 +6453,9 @@ perf_output_sample_ustack(struct perf_output_handle *handle, u64 dump_size, /* Data. */ sp = perf_user_stack_pointer(regs); - fs = get_fs(); - set_fs(USER_DS); + fs = force_uaccess_begin(); rem = __output_copy_user(handle, (void *) sp, dump_size); - set_fs(fs); + force_uaccess_end(fs); dyn_size = dump_size - rem; perf_output_skip(handle, rem); |