* [PATCH 4.9 014/102] MIPS: uprobes: remove set but not used variable epc
[not found] <20190708150525.973820964@linuxfoundation.org>
@ 2019-07-08 15:12 ` Greg Kroah-Hartman
2019-07-08 15:13 ` [PATCH 4.9 100/102] MIPS: Add missing EHB in mtc0 -> mfc0 sequence Greg Kroah-Hartman
1 sibling, 0 replies; 2+ messages in thread
From: Greg Kroah-Hartman @ 2019-07-08 15:12 UTC (permalink / raw)
To: linux-kernel
Cc: Greg Kroah-Hartman, stable, YueHaibing, Paul Burton, ralf,
jhogan, linux-mips, Sasha Levin
[ Upstream commit f532beeeff0c0a3586cc15538bc52d249eb19e7c ]
Fixes gcc '-Wunused-but-set-variable' warning:
arch/mips/kernel/uprobes.c: In function 'arch_uprobe_pre_xol':
arch/mips/kernel/uprobes.c:115:17: warning: variable 'epc' set but not used [-Wunused-but-set-variable]
It's never used since introduction in
commit 40e084a506eb ("MIPS: Add uprobes support.")
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Signed-off-by: Paul Burton <paul.burton@mips.com>
Cc: <ralf@linux-mips.org>
Cc: <jhogan@kernel.org>
Cc: <linux-kernel@vger.kernel.org>
Cc: <linux-mips@vger.kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
arch/mips/kernel/uprobes.c | 3 ---
1 file changed, 3 deletions(-)
diff --git a/arch/mips/kernel/uprobes.c b/arch/mips/kernel/uprobes.c
index dbb917403131..ec951dde0999 100644
--- a/arch/mips/kernel/uprobes.c
+++ b/arch/mips/kernel/uprobes.c
@@ -111,9 +111,6 @@ int arch_uprobe_pre_xol(struct arch_uprobe *aup, struct pt_regs *regs)
*/
aup->resume_epc = regs->cp0_epc + 4;
if (insn_has_delay_slot((union mips_instruction) aup->insn[0])) {
- unsigned long epc;
-
- epc = regs->cp0_epc;
__compute_return_epc_for_insn(regs,
(union mips_instruction) aup->insn[0]);
aup->resume_epc = regs->cp0_epc;
--
2.20.1
^ permalink raw reply related [flat|nested] 2+ messages in thread
* [PATCH 4.9 100/102] MIPS: Add missing EHB in mtc0 -> mfc0 sequence.
[not found] <20190708150525.973820964@linuxfoundation.org>
2019-07-08 15:12 ` [PATCH 4.9 014/102] MIPS: uprobes: remove set but not used variable epc Greg Kroah-Hartman
@ 2019-07-08 15:13 ` Greg Kroah-Hartman
1 sibling, 0 replies; 2+ messages in thread
From: Greg Kroah-Hartman @ 2019-07-08 15:13 UTC (permalink / raw)
To: linux-kernel
Cc: Greg Kroah-Hartman, stable, Dmitry Korotin, Paul Burton, linux-mips
From: Dmitry Korotin <dkorotin@wavecomp.com>
commit 0b24cae4d535045f4c9e177aa228d4e97bad212c upstream.
Add a missing EHB (Execution Hazard Barrier) in mtc0 -> mfc0 sequence.
Without this execution hazard barrier it's possible for the value read
back from the KScratch register to be the value from before the mtc0.
Reproducible on P5600 & P6600.
The hazard is documented in the MIPS Architecture Reference Manual Vol.
III: MIPS32/microMIPS32 Privileged Resource Architecture (MD00088), rev
6.03 table 8.1 which includes:
Producer | Consumer | Hazard
----------|----------|----------------------------
mtc0 | mfc0 | any coprocessor 0 register
Signed-off-by: Dmitry Korotin <dkorotin@wavecomp.com>
[paul.burton@mips.com:
- Commit message tweaks.
- Add Fixes tags.
- Mark for stable back to v3.15 where P5600 support was introduced.]
Signed-off-by: Paul Burton <paul.burton@mips.com>
Fixes: 3d8bfdd03072 ("MIPS: Use C0_KScratch (if present) to hold PGD pointer.")
Fixes: 829dcc0a956a ("MIPS: Add MIPS P5600 probe support")
Cc: linux-mips@vger.kernel.org
Cc: stable@vger.kernel.org # v3.15+
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
arch/mips/mm/tlbex.c | 29 ++++++++++++++++++++---------
1 file changed, 20 insertions(+), 9 deletions(-)
--- a/arch/mips/mm/tlbex.c
+++ b/arch/mips/mm/tlbex.c
@@ -386,6 +386,7 @@ static struct work_registers build_get_w
static void build_restore_work_registers(u32 **p)
{
if (scratch_reg >= 0) {
+ uasm_i_ehb(p);
UASM_i_MFC0(p, 1, c0_kscratch(), scratch_reg);
return;
}
@@ -674,10 +675,12 @@ static void build_restore_pagemask(u32 *
uasm_i_mtc0(p, 0, C0_PAGEMASK);
uasm_il_b(p, r, lid);
}
- if (scratch_reg >= 0)
+ if (scratch_reg >= 0) {
+ uasm_i_ehb(p);
UASM_i_MFC0(p, 1, c0_kscratch(), scratch_reg);
- else
+ } else {
UASM_i_LW(p, 1, scratchpad_offset(0), 0);
+ }
} else {
/* Reset default page size */
if (PM_DEFAULT_MASK >> 16) {
@@ -935,10 +938,12 @@ build_get_pgd_vmalloc64(u32 **p, struct
uasm_i_jr(p, ptr);
if (mode == refill_scratch) {
- if (scratch_reg >= 0)
+ if (scratch_reg >= 0) {
+ uasm_i_ehb(p);
UASM_i_MFC0(p, 1, c0_kscratch(), scratch_reg);
- else
+ } else {
UASM_i_LW(p, 1, scratchpad_offset(0), 0);
+ }
} else {
uasm_i_nop(p);
}
@@ -1238,6 +1243,7 @@ build_fast_tlb_refill_handler (u32 **p,
UASM_i_MTC0(p, odd, C0_ENTRYLO1); /* load it */
if (c0_scratch_reg >= 0) {
+ uasm_i_ehb(p);
UASM_i_MFC0(p, scratch, c0_kscratch(), c0_scratch_reg);
build_tlb_write_entry(p, l, r, tlb_random);
uasm_l_leave(l, *p);
@@ -1592,15 +1598,17 @@ static void build_setup_pgd(void)
uasm_i_dinsm(&p, a0, 0, 29, 64 - 29);
uasm_l_tlbl_goaround1(&l, p);
UASM_i_SLL(&p, a0, a0, 11);
- uasm_i_jr(&p, 31);
UASM_i_MTC0(&p, a0, C0_CONTEXT);
+ uasm_i_jr(&p, 31);
+ uasm_i_ehb(&p);
} else {
/* PGD in c0_KScratch */
- uasm_i_jr(&p, 31);
if (cpu_has_ldpte)
UASM_i_MTC0(&p, a0, C0_PWBASE);
else
UASM_i_MTC0(&p, a0, c0_kscratch(), pgd_reg);
+ uasm_i_jr(&p, 31);
+ uasm_i_ehb(&p);
}
#else
#ifdef CONFIG_SMP
@@ -1614,13 +1622,16 @@ static void build_setup_pgd(void)
UASM_i_LA_mostly(&p, a2, pgdc);
UASM_i_SW(&p, a0, uasm_rel_lo(pgdc), a2);
#endif /* SMP */
- uasm_i_jr(&p, 31);
/* if pgd_reg is allocated, save PGD also to scratch register */
- if (pgd_reg != -1)
+ if (pgd_reg != -1) {
UASM_i_MTC0(&p, a0, c0_kscratch(), pgd_reg);
- else
+ uasm_i_jr(&p, 31);
+ uasm_i_ehb(&p);
+ } else {
+ uasm_i_jr(&p, 31);
uasm_i_nop(&p);
+ }
#endif
if (p >= tlbmiss_handler_setup_pgd_end)
panic("tlbmiss_handler_setup_pgd space exceeded");
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[not found] <20190708150525.973820964@linuxfoundation.org>
2019-07-08 15:12 ` [PATCH 4.9 014/102] MIPS: uprobes: remove set but not used variable epc Greg Kroah-Hartman
2019-07-08 15:13 ` [PATCH 4.9 100/102] MIPS: Add missing EHB in mtc0 -> mfc0 sequence Greg Kroah-Hartman
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