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mirror of https://mirrors.bfsu.edu.cn/git/linux.git synced 2025-01-11 00:04:33 +08:00
linux/arch/x86
Alexei Starovoitov 13fac1d851 bpf: Fix trampoline generation for fmod_ret programs
fmod_ret progs are emitted as:

start = __bpf_prog_enter();
call fmod_ret
*(u64 *)(rbp - 8) = rax
__bpf_prog_exit(, start);
test eax, eax
jne do_fexit

That 'test eax, eax' is working by accident. The compiler is free to use rax
inside __bpf_prog_exit() or inside functions that __bpf_prog_exit() is calling.
Which caused "test_progs -t modify_return" to sporadically fail depending on
compiler version and kconfig. Fix it by using 'cmp [rbp - 8], 0' instead of
'test eax, eax'.

Fixes: ae24082331 ("bpf: Introduce BPF_MODIFY_RETURN")
Reported-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Acked-by: KP Singh <kpsingh@google.com>
Link: https://lore.kernel.org/bpf/20200311003906.3643037-1-ast@kernel.org
2020-03-11 14:07:32 +01:00
..
boot x86/boot/compressed: Don't declare __force_order in kaslr_64.c 2020-02-19 17:23:59 +01:00
configs x86: Remove the calgary IOMMU driver 2019-11-15 10:36:59 +01:00
crypto crypto: x86/poly1305 - emit does base conversion itself 2020-01-22 16:21:11 +08:00
entry kbuild: rename hostprogs-y/always to hostprogs/always-y 2020-02-04 01:53:07 +09:00
events perf/x86/intel: Fix inaccurate period in context switch for auto-reload 2020-02-11 13:23:27 +01:00
hyperv x86/hyperv: Suspend/resume the hypercall page for hibernation 2020-02-01 09:41:16 +01:00
ia32 x86: Remove force_iret() 2020-01-08 19:40:51 +01:00
include Bugfixes, including the fix for CVE-2020-2732 and a few 2020-02-24 11:48:17 -08:00
kernel Two fixes for the AMD MCE driver: 2020-02-22 18:02:10 -08:00
kvm Revert "KVM: x86: enable -Werror" 2020-02-26 09:59:58 -08:00
lib Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2020-01-31 11:05:33 -08:00
math-emu Merge branch 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2019-11-26 10:42:40 -08:00
mm x86: mm: avoid allocating struct mm_struct on the stack 2020-02-04 03:05:25 +00:00
net bpf: Fix trampoline generation for fmod_ret programs 2020-03-11 14:07:32 +01:00
oprofile x86: Use pr_warn instead of pr_warning 2019-10-18 15:00:18 +02:00
pci pci-v5.6-changes 2020-01-31 14:48:54 -08:00
platform A single fix for a EFI boot regression on X86 which was caused by the 2020-02-09 11:54:50 -08:00
power x86/asm/32: Change all ENTRY+ENDPROC to SYM_FUNC_* 2019-10-18 12:03:43 +02:00
purgatory Merge branch 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2019-11-26 10:42:40 -08:00
ras
realmode kbuild: rename hostprogs-y/always to hostprogs/always-y 2020-02-04 01:53:07 +09:00
tools kbuild: rename hostprogs-y/always to hostprogs/always-y 2020-02-04 01:53:07 +09:00
um um: Implement copy_thread_tls 2020-01-07 13:31:29 +01:00
video
xen xen: branch for v5.6-rc3 2020-02-21 16:10:10 -08:00
.gitignore
Kbuild
Kconfig asm-generic/tlb: rename HAVE_RCU_TABLE_FREE 2020-02-04 03:05:26 +00:00
Kconfig.cpu x86/cpu: Detect VMX features on Intel, Centaur and Zhaoxin CPUs 2020-01-13 18:02:53 +01:00
Kconfig.debug x86: mm: convert dump_pagetables to use walk_page_range 2020-02-04 03:05:25 +00:00
Makefile x86/build: Add -Wnoaddress-of-packed-member to REALMODE_CFLAGS, to silence GCC9 build warning 2019-08-28 17:31:31 +02:00
Makefile_32.cpu x86/math-emu: Limit MATH_EMULATION to 486SX compatibles 2019-10-03 10:51:17 +02:00
Makefile.um