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Merge branch 's390-bpf-add-s390-jit-support-for-timed-may_goto'

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Ilya Leoshkevich says:

====================
s390/bpf: Add s390 JIT support for timed may_goto

v1: https://lore.kernel.org/bpf/20250821103256.291412-1-iii@linux.ibm.com/
v1 -> v2: Fix test_stream_errors (caught by CI).

This series adds timed may_goto implementation to the s390x JIT.
Patch 1 is the implementation itself, patches 2-5 are the associated
test changes.
====================

Link: https://patch.msgid.link/20250821113339.292434-1-iii@linux.ibm.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
This commit is contained in:
Alexei Starovoitov
2025-08-26 16:52:07 -07:00
parent d0f27ff27c 21bce56940
commit 2465bb83e0
8 changed files with 81 additions and 10 deletions
Download Patch File Download Diff File Expand all files Collapse all files
arch/s390/net/Makefile
+1 -1
View File
@@ -2,5 +2,5 @@
#
# Arch-specific network modules
#
obj-$(CONFIG_BPF_JIT) += bpf_jit_comp.o
obj-$(CONFIG_BPF_JIT) += bpf_jit_comp.o bpf_timed_may_goto.o
obj-$(CONFIG_HAVE_PNETID) += pnet.o
arch/s390/net/bpf_jit_comp.c
+21 -4
View File
@@ -1806,10 +1806,22 @@ static noinline int bpf_jit_insn(struct bpf_jit *jit, struct bpf_prog *fp,
}
}
/* brasl %r14,func */
EMIT6_PCREL_RILB_PTR(0xc0050000, REG_14, (void *)func);
/* lgr %b0,%r2: load return value into %b0 */
EMIT4(0xb9040000, BPF_REG_0, REG_2);
if ((void *)func == arch_bpf_timed_may_goto) {
/*
* arch_bpf_timed_may_goto() has a special ABI: the
* parameters are in BPF_REG_AX and BPF_REG_10; the
* return value is in BPF_REG_AX; and all GPRs except
* REG_W0, REG_W1, and BPF_REG_AX are callee-saved.
*/
/* brasl %r0,func */
EMIT6_PCREL_RILB_PTR(0xc0050000, REG_0, (void *)func);
} else {
/* brasl %r14,func */
EMIT6_PCREL_RILB_PTR(0xc0050000, REG_14, (void *)func);
/* lgr %b0,%r2: load return value into %b0 */
EMIT4(0xb9040000, BPF_REG_0, REG_2);
}
/*
* Copy the potentially updated tail call counter back.
@@ -2993,3 +3005,8 @@ void arch_bpf_stack_walk(bool (*consume_fn)(void *, u64, u64, u64),
prev_addr = addr;
}
}
bool bpf_jit_supports_timed_may_goto(void)
{
return true;
}
arch/s390/net/bpf_timed_may_goto.S
+45
View File
@@ -0,0 +1,45 @@
/* SPDX-License-Identifier: GPL-2.0 */
#include <linux/export.h>
#include <linux/linkage.h>
#include <asm/asm-offsets.h>
#include <asm/nospec-insn.h>
#define R2_OFF 0
#define R5_OFF (R2_OFF + (5 - 2 + 1) * 8)
#define R14_OFF (R5_OFF + 8)
#define RETADDR_OFF (R14_OFF + 8)
#define R15_OFF (RETADDR_OFF + 8)
#define BACKCHAIN_OFF (R15_OFF + 8)
#define FRAME_SIZE (BACKCHAIN_OFF + 8)
#define FRAME_OFF (STACK_FRAME_OVERHEAD - FRAME_SIZE)
#if (FRAME_OFF + BACKCHAIN_OFF) != __SF_BACKCHAIN
#error Stack frame layout calculation is broken
#endif
GEN_BR_THUNK %r1
SYM_FUNC_START(arch_bpf_timed_may_goto)
/*
* This function has a special ABI: the parameters are in %r12 and
* %r13; the return value is in %r12; all GPRs except %r0, %r1, and
* %r12 are callee-saved; and the return address is in %r0.
*/
stmg %r2,%r5,FRAME_OFF+R2_OFF(%r15)
stg %r14,FRAME_OFF+R14_OFF(%r15)
stg %r0,FRAME_OFF+RETADDR_OFF(%r15)
stg %r15,FRAME_OFF+R15_OFF(%r15)
lgr %r1,%r15
lay %r15,-FRAME_SIZE(%r15)
stg %r1,__SF_BACKCHAIN(%r15)
lay %r2,0(%r12,%r13)
brasl %r14,bpf_check_timed_may_goto
lgr %r12,%r2
lg %r15,FRAME_SIZE+FRAME_OFF+R15_OFF(%r15)
lmg %r2,%r5,FRAME_OFF+R2_OFF(%r15)
lg %r14,FRAME_OFF+R14_OFF(%r15)
lg %r1,FRAME_OFF+RETADDR_OFF(%r15)
BR_EX %r1
SYM_FUNC_END(arch_bpf_timed_may_goto)
tools/testing/selftests/bpf/DENYLIST.s390x
-1
View File
@@ -2,4 +2,3 @@
# Alphabetical order
get_stack_raw_tp # user_stack corrupted user stack (no backchain userspace)
stacktrace_build_id # compare_map_keys stackid_hmap vs. stackmap err -2 errno 2 (?)
verifier_iterating_callbacks
tools/testing/selftests/bpf/prog_tests/stream.c
+1 -1
View File
@@ -77,7 +77,7 @@ void test_stream_errors(void)
ASSERT_OK(ret, "ret");
ASSERT_OK(opts.retval, "retval");
#if !defined(__x86_64__)
#if !defined(__x86_64__) && !defined(__s390x__)
ASSERT_TRUE(1, "Timed may_goto unsupported, skip.");
if (i == 0) {
ret = bpf_prog_stream_read(prog_fd, 2, buf, sizeof(buf), &ropts);
tools/testing/selftests/bpf/progs/bpf_misc.h
+1
View File
@@ -136,6 +136,7 @@
#define __arch_x86_64 __arch("X86_64")
#define __arch_arm64 __arch("ARM64")
#define __arch_riscv64 __arch("RISCV64")
#define __arch_s390x __arch("s390x")
#define __caps_unpriv(caps) __attribute__((btf_decl_tag("comment:test_caps_unpriv=" EXPAND_QUOTE(caps))))
#define __load_if_JITed() __attribute__((btf_decl_tag("comment:load_mode=jited")))
#define __load_if_no_JITed() __attribute__((btf_decl_tag("comment:load_mode=no_jited")))
tools/testing/selftests/bpf/progs/verifier_may_goto_1.c
+6 -2
View File
@@ -9,6 +9,7 @@
SEC("raw_tp")
__description("may_goto 0")
__arch_x86_64
__arch_s390x
__xlated("0: r0 = 1")
__xlated("1: exit")
__success
@@ -27,6 +28,7 @@ __naked void may_goto_simple(void)
SEC("raw_tp")
__description("batch 2 of may_goto 0")
__arch_x86_64
__arch_s390x
__xlated("0: r0 = 1")
__xlated("1: exit")
__success
@@ -47,6 +49,7 @@ __naked void may_goto_batch_0(void)
SEC("raw_tp")
__description("may_goto batch with offsets 2/1/0")
__arch_x86_64
__arch_s390x
__xlated("0: r0 = 1")
__xlated("1: exit")
__success
@@ -69,8 +72,9 @@ __naked void may_goto_batch_1(void)
}
SEC("raw_tp")
__description("may_goto batch with offsets 2/0 - x86_64")
__description("may_goto batch with offsets 2/0 - x86_64 and s390x")
__arch_x86_64
__arch_s390x
__xlated("0: *(u64 *)(r10 -16) = 65535")
__xlated("1: *(u64 *)(r10 -8) = 0")
__xlated("2: r11 = *(u64 *)(r10 -16)")
@@ -84,7 +88,7 @@ __xlated("9: r0 = 1")
__xlated("10: r0 = 2")
__xlated("11: exit")
__success
__naked void may_goto_batch_2_x86_64(void)
__naked void may_goto_batch_2_x86_64_s390x(void)
{
asm volatile (
".8byte %[may_goto1];"
tools/testing/selftests/bpf/test_loader.c
+6 -1
View File
@@ -374,6 +374,7 @@ enum arch {
ARCH_X86_64 = 0x2,
ARCH_ARM64 = 0x4,
ARCH_RISCV64 = 0x8,
ARCH_S390X = 0x10,
};
static int get_current_arch(void)
@@ -384,6 +385,8 @@ static int get_current_arch(void)
return ARCH_ARM64;
#elif defined(__riscv) && __riscv_xlen == 64
return ARCH_RISCV64;
#elif defined(__s390x__)
return ARCH_S390X;
#endif
return ARCH_UNKNOWN;
}
@@ -565,8 +568,10 @@ static int parse_test_spec(struct test_loader *tester,
arch = ARCH_ARM64;
} else if (strcmp(val, "RISCV64") == 0) {
arch = ARCH_RISCV64;
} else if (strcmp(val, "s390x") == 0) {
arch = ARCH_S390X;
} else {
PRINT_FAIL("bad arch spec: '%s'", val);
PRINT_FAIL("bad arch spec: '%s'\n", val);
err = -EINVAL;
goto cleanup;
}