projects / thirdparty / kernel / stable-queue.git / blame
| Commit | Line | Data |
|---|---|---|
| 65418671 SL |
1 | From 42449e3341fdbe8209742950c33e313417c1284d Mon Sep 17 00:00:00 2001 |
| 2 | From: Ilya Leoshkevich <iii@linux.ibm.com> | |
| 3 | Date: Fri, 21 Jun 2019 17:39:12 +0200 | |
| 4 | Subject: s390/jump_label: Use "jdd" constraint on gcc9 | |
| 5 | ||
| 6 | [ Upstream commit 146448524bddbf6dfc62de31957e428de001cbda ] | |
| 7 | ||
| 8 | [heiko.carstens@de.ibm.com]: | |
| 9 | ----- | |
| 10 | Laura Abbott reported that the kernel doesn't build anymore with gcc 9, | |
| 11 | due to the "X" constraint. Ilya provided the gcc 9 patch "S/390: | |
| 12 | Introduce jdd constraint" which introduces the new "jdd" constraint | |
| 13 | which fixes this. | |
| 14 | ----- | |
| 15 | ||
| 16 | The support for section anchors on S/390 introduced in gcc9 has changed | |
| 17 | the behavior of "X" constraint, which can now produce register | |
| 18 | references. Since existing constraints, in particular, "i", do not fit | |
| 19 | the intended use case on S/390, the new machine-specific "jdd" | |
| 20 | constraint was introduced. This patch makes jump labels use "jdd" | |
| 21 | constraint when building with gcc9. | |
| 22 | ||
| 23 | Reported-by: Laura Abbott <labbott@redhat.com> | |
| 24 | Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com> | |
| 25 | Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> | |
| 26 | Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> | |
| 27 | Signed-off-by: Sasha Levin <sashal@kernel.org> | |
| 28 | --- | |
| 29 | arch/s390/include/asm/jump_label.h | 14 ++++++++++---- | |
| 30 | 1 file changed, 10 insertions(+), 4 deletions(-) | |
| 31 | ||
| 32 | diff --git a/arch/s390/include/asm/jump_label.h b/arch/s390/include/asm/jump_label.h | |
| 33 | index 40f651292aa7..9c7dc970e966 100644 | |
| 34 | --- a/arch/s390/include/asm/jump_label.h | |
| 35 | +++ b/arch/s390/include/asm/jump_label.h | |
| 36 | @@ -10,6 +10,12 @@ | |
| 37 | #define JUMP_LABEL_NOP_SIZE 6 | |
| 38 | #define JUMP_LABEL_NOP_OFFSET 2 | |
| 39 | ||
| 40 | +#if __GNUC__ < 9 | |
| 41 | +#define JUMP_LABEL_STATIC_KEY_CONSTRAINT "X" | |
| 42 | +#else | |
| 43 | +#define JUMP_LABEL_STATIC_KEY_CONSTRAINT "jdd" | |
| 44 | +#endif | |
| 45 | + | |
| 46 | /* | |
| 47 | * We use a brcl 0,2 instruction for jump labels at compile time so it | |
| 48 | * can be easily distinguished from a hotpatch generated instruction. | |
| 49 | @@ -19,9 +25,9 @@ static __always_inline bool arch_static_branch(struct static_key *key, bool bran | |
| 50 | asm_volatile_goto("0: brcl 0,"__stringify(JUMP_LABEL_NOP_OFFSET)"\n" | |
| 51 | ".pushsection __jump_table, \"aw\"\n" | |
| 52 | ".balign 8\n" | |
| 53 | - ".quad 0b, %l[label], %0\n" | |
| 54 | + ".quad 0b, %l[label], %0+%1\n" | |
| 55 | ".popsection\n" | |
| 56 | - : : "X" (&((char *)key)[branch]) : : label); | |
| 57 | + : : JUMP_LABEL_STATIC_KEY_CONSTRAINT (key), "i" (branch) : : label); | |
| 58 | ||
| 59 | return false; | |
| 60 | label: | |
| 61 | @@ -33,9 +39,9 @@ static __always_inline bool arch_static_branch_jump(struct static_key *key, bool | |
| 62 | asm_volatile_goto("0: brcl 15, %l[label]\n" | |
| 63 | ".pushsection __jump_table, \"aw\"\n" | |
| 64 | ".balign 8\n" | |
| 65 | - ".quad 0b, %l[label], %0\n" | |
| 66 | + ".quad 0b, %l[label], %0+%1\n" | |
| 67 | ".popsection\n" | |
| 68 | - : : "X" (&((char *)key)[branch]) : : label); | |
| 69 | + : : JUMP_LABEL_STATIC_KEY_CONSTRAINT (key), "i" (branch) : : label); | |
| 70 | ||
| 71 | return false; | |
| 72 | label: | |
| 73 | -- | |
| 74 | 2.20.1 | |
| 75 |