From: Andy Lutomirski <luto(a)kernel.org>
[ Upstream commit 716572b0003ef67a4889bd7d85baf5099c5a0248 ]
Setting GS to 1, 2, or 3 causes a nonsensical part of the IRET microcode
to change GS back to zero on a return from kernel mode to user mode. The
result is that these tests fail randomly depending on when interrupts
happen. Detect when this happens and let the test pass.
Signed-off-by: Andy Lutomirski <luto(a)kernel.org>
Signed-off-by: Borislav Petkov <bp(a)suse.de>
Link: https://lkml.kernel.org/r/7567fd44a1d60a9424f25b19a998f12149993b0d.16043465…
Signed-off-by: Sasha Levin <sashal(a)kernel.org>
---
tools/testing/selftests/x86/fsgsbase.c | 12 ++++++++++--
1 file changed, 10 insertions(+), 2 deletions(-)
diff --git a/tools/testing/selftests/x86/fsgsbase.c b/tools/testing/selftests/x86/fsgsbase.c
index 757bdb218a661..f2916838a7eb5 100644
--- a/tools/testing/selftests/x86/fsgsbase.c
+++ b/tools/testing/selftests/x86/fsgsbase.c
@@ -391,8 +391,8 @@ static void set_gs_and_switch_to(unsigned long local,
local = read_base(GS);
/*
- * Signal delivery seems to mess up weird selectors. Put it
- * back.
+ * Signal delivery is quite likely to change a selector
+ * of 1, 2, or 3 back to 0 due to IRET being defective.
*/
asm volatile ("mov %0, %%gs" : : "rm" (force_sel));
} else {
@@ -410,6 +410,14 @@ static void set_gs_and_switch_to(unsigned long local,
if (base == local && sel_pre_sched == sel_post_sched) {
printf("[OK]\tGS/BASE remained 0x%hx/0x%lx\n",
sel_pre_sched, local);
+ } else if (base == local && sel_pre_sched >= 1 && sel_pre_sched <= 3 &&
+ sel_post_sched == 0) {
+ /*
+ * IRET is misdesigned and will squash selectors 1, 2, or 3
+ * to zero. Don't fail the test just because this happened.
+ */
+ printf("[OK]\tGS/BASE changed from 0x%hx/0x%lx to 0x%hx/0x%lx because IRET is defective\n",
+ sel_pre_sched, local, sel_post_sched, base);
} else {
nerrs++;
printf("[FAIL]\tGS/BASE changed from 0x%hx/0x%lx to 0x%hx/0x%lx\n",
--
2.27.0
From: Jean-Philippe Brucker <jean-philippe(a)linaro.org>
[ Upstream commit 77ce220c0549dcc3db8226c61c60e83fc59dfafc ]
The test fails because of a recent fix to the verifier, even though this
program is valid. In details what happens is:
7: (61) r1 = *(u32 *)(r0 +0)
Load a 32-bit value, with signed bounds [S32_MIN, S32_MAX]. The bounds
of the 64-bit value are [0, U32_MAX]...
8: (65) if r1 s> 0xffffffff goto pc+1
... therefore this is always true (the operand is sign-extended).
10: (b4) w2 = 11
11: (6d) if r2 s> r1 goto pc+1
When true, the 64-bit bounds become [0, 10]. The 32-bit bounds are still
[S32_MIN, 10].
13: (64) w1 <<= 2
Because this is a 32-bit operation, the verifier propagates the new
32-bit bounds to the 64-bit ones, and the knowledge gained from insn 11
is lost.
14: (0f) r0 += r1
15: (7a) *(u64 *)(r0 +0) = 4
Then the verifier considers r0 unbounded here, rejecting the test. To
make the test work, change insn 8 to check the sign of the 32-bit value.
Signed-off-by: Jean-Philippe Brucker <jean-philippe(a)linaro.org>
Acked-by: John Fastabend <john.fastabend(a)gmail.com>
Signed-off-by: Alexei Starovoitov <ast(a)kernel.org>
Signed-off-by: Sasha Levin <sashal(a)kernel.org>
---
tools/testing/selftests/bpf/verifier/array_access.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/tools/testing/selftests/bpf/verifier/array_access.c b/tools/testing/selftests/bpf/verifier/array_access.c
index f3c33e128709b..a80d806ead15f 100644
--- a/tools/testing/selftests/bpf/verifier/array_access.c
+++ b/tools/testing/selftests/bpf/verifier/array_access.c
@@ -68,7 +68,7 @@
BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, BPF_FUNC_map_lookup_elem),
BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 9),
BPF_LDX_MEM(BPF_W, BPF_REG_1, BPF_REG_0, 0),
- BPF_JMP_IMM(BPF_JSGT, BPF_REG_1, 0xffffffff, 1),
+ BPF_JMP32_IMM(BPF_JSGT, BPF_REG_1, 0xffffffff, 1),
BPF_MOV32_IMM(BPF_REG_1, 0),
BPF_MOV32_IMM(BPF_REG_2, MAX_ENTRIES),
BPF_JMP_REG(BPF_JSGT, BPF_REG_2, BPF_REG_1, 1),
--
2.27.0
On Sat, Dec 12, 2020 at 5:18 PM Guenter Roeck <linux(a)roeck-us.net> wrote:
>
> This patch results in:
>
> arch/sh/kernel/cpu/sh4a/smp-shx3.c: In function 'shx3_prepare_cpus':
> arch/sh/kernel/cpu/sh4a/smp-shx3.c:76:3: error: ignoring return value of 'request_irq' declared with attribute 'warn_unused_result'
>
> when building sh:defconfig. Checking for calls to request_irq()
> suggests that there will be other similar errors in various builds.
> Reverting the patch fixes the problem.
Which ones? From a quick grep and some filtering I could only find one
file with wrong usage apart from this one:
drivers/net/ethernet/lantiq_etop.c:
request_irq(irq, ltq_etop_dma_irq, 0, "etop_tx", priv);
drivers/net/ethernet/lantiq_etop.c:
request_irq(irq, ltq_etop_dma_irq, 0, "etop_rx", priv);
Of course, this does not cover other functions, but it means there
aren't many issues and/or people building the code if nobody complains
within a few weeks. So I think we can fix them as they come.
Cheers,
Miguel
From: Jean-Philippe Brucker <jean-philippe(a)linaro.org>
[ Upstream commit 3615bdf6d9b19db12b1589861609b4f1c6a8d303 ]
The verifier trace changed following a bugfix. After checking the 64-bit
sign, only the upper bit mask is known, not bit 31. Update the test
accordingly.
Signed-off-by: Jean-Philippe Brucker <jean-philippe(a)linaro.org>
Acked-by: John Fastabend <john.fastabend(a)gmail.com>
Signed-off-by: Alexei Starovoitov <ast(a)kernel.org>
Signed-off-by: Sasha Levin <sashal(a)kernel.org>
---
tools/testing/selftests/bpf/prog_tests/align.c | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)
diff --git a/tools/testing/selftests/bpf/prog_tests/align.c b/tools/testing/selftests/bpf/prog_tests/align.c
index c548aded65859..2a15aa3d49c74 100644
--- a/tools/testing/selftests/bpf/prog_tests/align.c
+++ b/tools/testing/selftests/bpf/prog_tests/align.c
@@ -456,10 +456,10 @@ static struct bpf_align_test tests[] = {
*/
{7, "R5_w=inv(id=0,smin_value=-9223372036854775806,smax_value=9223372036854775806,umin_value=2,umax_value=18446744073709551614,var_off=(0x2; 0xfffffffffffffffc)"},
/* Checked s>=0 */
- {9, "R5=inv(id=0,umin_value=2,umax_value=9223372034707292158,var_off=(0x2; 0x7fffffff7ffffffc)"},
+ {9, "R5=inv(id=0,umin_value=2,umax_value=9223372036854775806,var_off=(0x2; 0x7ffffffffffffffc)"},
/* packet pointer + nonnegative (4n+2) */
- {11, "R6_w=pkt(id=1,off=0,r=0,umin_value=2,umax_value=9223372034707292158,var_off=(0x2; 0x7fffffff7ffffffc)"},
- {13, "R4_w=pkt(id=1,off=4,r=0,umin_value=2,umax_value=9223372034707292158,var_off=(0x2; 0x7fffffff7ffffffc)"},
+ {11, "R6_w=pkt(id=1,off=0,r=0,umin_value=2,umax_value=9223372036854775806,var_off=(0x2; 0x7ffffffffffffffc)"},
+ {13, "R4_w=pkt(id=1,off=4,r=0,umin_value=2,umax_value=9223372036854775806,var_off=(0x2; 0x7ffffffffffffffc)"},
/* NET_IP_ALIGN + (4n+2) == (4n), alignment is fine.
* We checked the bounds, but it might have been able
* to overflow if the packet pointer started in the
@@ -467,7 +467,7 @@ static struct bpf_align_test tests[] = {
* So we did not get a 'range' on R6, and the access
* attempt will fail.
*/
- {15, "R6_w=pkt(id=1,off=0,r=0,umin_value=2,umax_value=9223372034707292158,var_off=(0x2; 0x7fffffff7ffffffc)"},
+ {15, "R6_w=pkt(id=1,off=0,r=0,umin_value=2,umax_value=9223372036854775806,var_off=(0x2; 0x7ffffffffffffffc)"},
}
},
{
--
2.27.0
From: Jean-Philippe Brucker <jean-philippe(a)linaro.org>
[ Upstream commit 77ce220c0549dcc3db8226c61c60e83fc59dfafc ]
The test fails because of a recent fix to the verifier, even though this
program is valid. In details what happens is:
7: (61) r1 = *(u32 *)(r0 +0)
Load a 32-bit value, with signed bounds [S32_MIN, S32_MAX]. The bounds
of the 64-bit value are [0, U32_MAX]...
8: (65) if r1 s> 0xffffffff goto pc+1
... therefore this is always true (the operand is sign-extended).
10: (b4) w2 = 11
11: (6d) if r2 s> r1 goto pc+1
When true, the 64-bit bounds become [0, 10]. The 32-bit bounds are still
[S32_MIN, 10].
13: (64) w1 <<= 2
Because this is a 32-bit operation, the verifier propagates the new
32-bit bounds to the 64-bit ones, and the knowledge gained from insn 11
is lost.
14: (0f) r0 += r1
15: (7a) *(u64 *)(r0 +0) = 4
Then the verifier considers r0 unbounded here, rejecting the test. To
make the test work, change insn 8 to check the sign of the 32-bit value.
Signed-off-by: Jean-Philippe Brucker <jean-philippe(a)linaro.org>
Acked-by: John Fastabend <john.fastabend(a)gmail.com>
Signed-off-by: Alexei Starovoitov <ast(a)kernel.org>
Signed-off-by: Sasha Levin <sashal(a)kernel.org>
---
tools/testing/selftests/bpf/verifier/array_access.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/tools/testing/selftests/bpf/verifier/array_access.c b/tools/testing/selftests/bpf/verifier/array_access.c
index 1c4b1939f5a8d..bed53b561e044 100644
--- a/tools/testing/selftests/bpf/verifier/array_access.c
+++ b/tools/testing/selftests/bpf/verifier/array_access.c
@@ -68,7 +68,7 @@
BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, BPF_FUNC_map_lookup_elem),
BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 9),
BPF_LDX_MEM(BPF_W, BPF_REG_1, BPF_REG_0, 0),
- BPF_JMP_IMM(BPF_JSGT, BPF_REG_1, 0xffffffff, 1),
+ BPF_JMP32_IMM(BPF_JSGT, BPF_REG_1, 0xffffffff, 1),
BPF_MOV32_IMM(BPF_REG_1, 0),
BPF_MOV32_IMM(BPF_REG_2, MAX_ENTRIES),
BPF_JMP_REG(BPF_JSGT, BPF_REG_2, BPF_REG_1, 1),
--
2.27.0