On 11/21/2017 07:18 AM, Mathieu Desnoyers wrote:

Fixes assembler errors: /tmp/cceKwI9a.s: Assembler messages: /tmp/cceKwI9a.s:849: Error: co-processor offset out of range

with gcc prior to gcc-7. This can trigger if multiple rseq inline asm are used within the same function.

My best guess on the cause of this issue is that gcc has a hard time figuring out the actual size of the inline asm, and therefore does not compute the offsets at which literal values can be placed from the program counter accurately.

Signed-off-by: Mathieu Desnoyers mathieu.desnoyers@efficios.com CC: "Paul E. McKenney" paulmck@linux.vnet.ibm.com CC: Peter Zijlstra peterz@infradead.org CC: Paul Turner pjt@google.com CC: Thomas Gleixner tglx@linutronix.de CC: Andrew Hunter ahh@google.com CC: Andy Lutomirski luto@amacapital.net CC: Andi Kleen andi@firstfloor.org CC: Dave Watson davejwatson@fb.com CC: Chris Lameter cl@linux.com CC: Ingo Molnar mingo@redhat.com CC: "H. Peter Anvin" hpa@zytor.com CC: Ben Maurer bmaurer@fb.com CC: Steven Rostedt rostedt@goodmis.org CC: Josh Triplett josh@joshtriplett.org CC: Linus Torvalds torvalds@linux-foundation.org CC: Andrew Morton akpm@linux-foundation.org CC: Russell King linux@arm.linux.org.uk CC: Catalin Marinas catalin.marinas@arm.com CC: Will Deacon will.deacon@arm.com CC: Michael Kerrisk mtk.manpages@gmail.com CC: Boqun Feng boqun.feng@gmail.com CC: Florian Weimer fweimer@redhat.com CC: Shuah Khan shuah@kernel.org CC: linux-kselftest@vger.kernel.org CC: linux-api@vger.kernel.org

---

tools/testing/selftests/rseq/rseq-arm.h | 33 +++++++++++++++++++++++++++++++++ 1 file changed, 33 insertions(+)

diff --git a/tools/testing/selftests/rseq/rseq-arm.h b/tools/testing/selftests/rseq/rseq-arm.h index 47953c0cef4f..6d3fda276f4d 100644 --- a/tools/testing/selftests/rseq/rseq-arm.h +++ b/tools/testing/selftests/rseq/rseq-arm.h @@ -79,12 +79,15 @@ do { \ teardown \ "b %l[" __rseq_str(cmpfail_label) "]\n\t" +#define rseq_workaround_gcc_asm_size_guess() __asm__ __volatile__("")

static inline __attribute__((always_inline)) int rseq_cmpeqv_storev(intptr_t *v, intptr_t expect, intptr_t newv, int cpu) { RSEQ_INJECT_C(9)

• rseq_workaround_gcc_asm_size_guess(); __asm__ __volatile__ goto ( RSEQ_ASM_DEFINE_TABLE(__rseq_table, 0x0, 0x0, 1f, 2f-1f, 4f) RSEQ_ASM_STORE_RSEQ_CS(1, 3f, rseq_cs)

@@ -115,11 +118,14 @@ int rseq_cmpeqv_storev(intptr_t *v, intptr_t expect, intptr_t newv, RSEQ_INJECT_CLOBBER : abort, cmpfail );

• rseq_workaround_gcc_asm_size_guess(); return 0;

abort:

• rseq_workaround_gcc_asm_size_guess(); RSEQ_INJECT_FAILED return -1;

cmpfail:

• rseq_workaround_gcc_asm_size_guess(); return 1;

} @@ -129,6 +135,7 @@ int rseq_cmpnev_storeoffp_load(intptr_t *v, intptr_t expectnot, { RSEQ_INJECT_C(9)

• rseq_workaround_gcc_asm_size_guess(); __asm__ __volatile__ goto ( RSEQ_ASM_DEFINE_TABLE(__rseq_table, 0x0, 0x0, 1f, 2f-1f, 4f) RSEQ_ASM_STORE_RSEQ_CS(1, 3f, rseq_cs)

@@ -164,11 +171,14 @@ int rseq_cmpnev_storeoffp_load(intptr_t *v, intptr_t expectnot, RSEQ_INJECT_CLOBBER : abort, cmpfail );

• rseq_workaround_gcc_asm_size_guess(); return 0;

abort:

• rseq_workaround_gcc_asm_size_guess(); RSEQ_INJECT_FAILED return -1;

cmpfail:

• rseq_workaround_gcc_asm_size_guess(); return 1;

} @@ -177,6 +187,7 @@ int rseq_addv(intptr_t *v, intptr_t count, int cpu) { RSEQ_INJECT_C(9)

• rseq_workaround_gcc_asm_size_guess(); __asm__ __volatile__ goto ( RSEQ_ASM_DEFINE_TABLE(__rseq_table, 0x0, 0x0, 1f, 2f-1f, 4f) RSEQ_ASM_STORE_RSEQ_CS(1, 3f, rseq_cs)

@@ -203,8 +214,10 @@ int rseq_addv(intptr_t *v, intptr_t count, int cpu) RSEQ_INJECT_CLOBBER : abort );

• rseq_workaround_gcc_asm_size_guess(); return 0;

abort:

• rseq_workaround_gcc_asm_size_guess(); RSEQ_INJECT_FAILED return -1;

} @@ -216,6 +229,7 @@ int rseq_cmpeqv_trystorev_storev(intptr_t *v, intptr_t expect, { RSEQ_INJECT_C(9)

• rseq_workaround_gcc_asm_size_guess(); __asm__ __volatile__ goto ( RSEQ_ASM_DEFINE_TABLE(__rseq_table, 0x0, 0x0, 1f, 2f-1f, 4f) RSEQ_ASM_STORE_RSEQ_CS(1, 3f, rseq_cs)

@@ -253,11 +267,14 @@ int rseq_cmpeqv_trystorev_storev(intptr_t *v, intptr_t expect, RSEQ_INJECT_CLOBBER : abort, cmpfail );

• rseq_workaround_gcc_asm_size_guess(); return 0;

abort:

• rseq_workaround_gcc_asm_size_guess(); RSEQ_INJECT_FAILED return -1;

cmpfail:

• rseq_workaround_gcc_asm_size_guess(); return 1;

} @@ -268,6 +285,7 @@ int rseq_cmpeqv_trystorev_storev_release(intptr_t *v, intptr_t expect, { RSEQ_INJECT_C(9)

• rseq_workaround_gcc_asm_size_guess(); __asm__ __volatile__ goto ( RSEQ_ASM_DEFINE_TABLE(__rseq_table, 0x0, 0x0, 1f, 2f-1f, 4f) RSEQ_ASM_STORE_RSEQ_CS(1, 3f, rseq_cs)

@@ -306,11 +324,14 @@ int rseq_cmpeqv_trystorev_storev_release(intptr_t *v, intptr_t expect, RSEQ_INJECT_CLOBBER : abort, cmpfail );

• rseq_workaround_gcc_asm_size_guess(); return 0;

abort:

• rseq_workaround_gcc_asm_size_guess(); RSEQ_INJECT_FAILED return -1;

cmpfail:

• rseq_workaround_gcc_asm_size_guess(); return 1;

} @@ -321,6 +342,7 @@ int rseq_cmpeqv_cmpeqv_storev(intptr_t *v, intptr_t expect, { RSEQ_INJECT_C(9)

• rseq_workaround_gcc_asm_size_guess(); __asm__ __volatile__ goto ( RSEQ_ASM_DEFINE_TABLE(__rseq_table, 0x0, 0x0, 1f, 2f-1f, 4f) RSEQ_ASM_STORE_RSEQ_CS(1, 3f, rseq_cs)

@@ -359,11 +381,14 @@ int rseq_cmpeqv_cmpeqv_storev(intptr_t *v, intptr_t expect, RSEQ_INJECT_CLOBBER : abort, cmpfail );

• rseq_workaround_gcc_asm_size_guess(); return 0;

abort:

• rseq_workaround_gcc_asm_size_guess(); RSEQ_INJECT_FAILED return -1;

cmpfail:

• rseq_workaround_gcc_asm_size_guess(); return 1;

} @@ -376,6 +401,7 @@ int rseq_cmpeqv_trymemcpy_storev(intptr_t *v, intptr_t expect, RSEQ_INJECT_C(9)

• rseq_workaround_gcc_asm_size_guess(); __asm__ __volatile__ goto ( RSEQ_ASM_DEFINE_TABLE(__rseq_table, 0x0, 0x0, 1f, 2f-1f, 4f) "str %[src], %[rseq_scratch0]\n\t"

@@ -442,11 +468,14 @@ int rseq_cmpeqv_trymemcpy_storev(intptr_t *v, intptr_t expect, RSEQ_INJECT_CLOBBER : abort, cmpfail );

• rseq_workaround_gcc_asm_size_guess(); return 0;

abort:

• rseq_workaround_gcc_asm_size_guess(); RSEQ_INJECT_FAILED return -1;

cmpfail:

• rseq_workaround_gcc_asm_size_guess(); return 1;

} @@ -459,6 +488,7 @@ int rseq_cmpeqv_trymemcpy_storev_release(intptr_t *v, intptr_t expect, RSEQ_INJECT_C(9)

• rseq_workaround_gcc_asm_size_guess(); __asm__ __volatile__ goto ( RSEQ_ASM_DEFINE_TABLE(__rseq_table, 0x0, 0x0, 1f, 2f-1f, 4f) "str %[src], %[rseq_scratch0]\n\t"

@@ -526,10 +556,13 @@ int rseq_cmpeqv_trymemcpy_storev_release(intptr_t *v, intptr_t expect, RSEQ_INJECT_CLOBBER : abort, cmpfail );

• rseq_workaround_gcc_asm_size_guess(); return 0;

abort:

• rseq_workaround_gcc_asm_size_guess(); RSEQ_INJECT_FAILED return -1;

cmpfail:

• rseq_workaround_gcc_asm_size_guess(); return 1;

}

Looks fine to me. For this patch.

Acked-by: Shuah Khan shuahkh@osg.samsung.com

I have comments on other patches in this series.

thanks, -- Shuah -- To unsubscribe from this list: send the line "unsubscribe linux-kselftest" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html