diff mbox series

[bpf-next,v1,2/3] bpf: Fix bpf_throw warning on 32-bit arch

Message ID 20230918143914.292526-3-memxor@gmail.com (mailing list archive)
State Superseded
Delegated to: BPF
Headers show
Series Fixes for Exceptions | expand

Checks

Context Check Description
netdev/series_format success Posting correctly formatted
netdev/tree_selection success Clearly marked for bpf-next
netdev/fixes_present success Fixes tag not required for -next series
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 1384 this patch: 1383
netdev/cc_maintainers fail 1 blamed authors not CCed: andreyknvl@gmail.com; 7 maintainers not CCed: andreyknvl@gmail.com jolsa@kernel.org haoluo@google.com sdf@google.com john.fastabend@gmail.com kpsingh@kernel.org song@kernel.org
netdev/build_clang success Errors and warnings before: 1364 this patch: 1364
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/deprecated_api success None detected
netdev/check_selftest success No net selftest shell script
netdev/verify_fixes success Fixes tag looks correct
netdev/build_allmodconfig_warn success Errors and warnings before: 1406 this patch: 1406
netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 8 lines checked
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0

Commit Message

Kumar Kartikeya Dwivedi Sept. 18, 2023, 2:39 p.m. UTC
On 32-bit architectures, the pointer width is 32-bit, while we try to
cast from a u64 down to it, the compiler complains on mismatch in
integer size. Fix this by first casting to long which should match
the pointer width on targets supported by Linux.

Fixes: ec5290a178b7 ("bpf: Prevent KASAN false positive with bpf_throw")
Reported-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
---
 kernel/bpf/helpers.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
diff mbox series

Patch

diff --git a/kernel/bpf/helpers.c b/kernel/bpf/helpers.c
index 7ff2a42f1996..dd1c69ee3375 100644
--- a/kernel/bpf/helpers.c
+++ b/kernel/bpf/helpers.c
@@ -2488,7 +2488,7 @@  __bpf_kfunc void bpf_throw(u64 cookie)
 	 * deeper stack depths than ctx.sp as we do not return from bpf_throw,
 	 * which skips compiler generated instrumentation to do the same.
 	 */
-	kasan_unpoison_task_stack_below((void *)ctx.sp);
+	kasan_unpoison_task_stack_below((void *)(long)ctx.sp);
 	ctx.aux->bpf_exception_cb(cookie, ctx.sp, ctx.bp);
 	WARN(1, "A call to BPF exception callback should never return\n");
 }