From 86d4d068df573a8c2105554624796c086d6bec3d Mon Sep 17 00:00:00 2001 From: John David Anglin Date: Tue, 6 Nov 2018 12:00:01 +0100 Subject: parisc: Revert "Release spinlocks using ordered store" This reverts commit d27dfa13b9f77ae7e6ed09d70a0426ed26c1a8f9. Unfortunately, this patch needs to be reverted. We need the full sync barrier and not the limited barrier provided by using an ordered store. The sync ensures that all accesses and cache purge instructions that follow the sync are performed after all such instructions prior the sync instruction have completed executing. The patch breaks the rwlock implementation in glibc. This caused the test-lock application in the libprelude testsuite to hang. With the change reverted, the test runs correctly and the libprelude package builds successfully. Signed-off-by: John David Anglin Signed-off-by: Helge Deller --- arch/parisc/include/asm/spinlock.h | 4 ++-- arch/parisc/kernel/syscall.S | 12 ++++++++---- 2 files changed, 10 insertions(+), 6 deletions(-) (limited to 'arch/parisc') diff --git a/arch/parisc/include/asm/spinlock.h b/arch/parisc/include/asm/spinlock.h index 16aec9ba2580..8a63515f03bf 100644 --- a/arch/parisc/include/asm/spinlock.h +++ b/arch/parisc/include/asm/spinlock.h @@ -37,8 +37,8 @@ static inline void arch_spin_unlock(arch_spinlock_t *x) volatile unsigned int *a; a = __ldcw_align(x); - /* Release with ordered store. */ - __asm__ __volatile__("stw,ma %0,0(%1)" : : "r"(1), "r"(a) : "memory"); + mb(); + *a = 1; } static inline int arch_spin_trylock(arch_spinlock_t *x) diff --git a/arch/parisc/kernel/syscall.S b/arch/parisc/kernel/syscall.S index 9505c317818d..a9bc90dc4ae7 100644 --- a/arch/parisc/kernel/syscall.S +++ b/arch/parisc/kernel/syscall.S @@ -640,7 +640,8 @@ cas_action: sub,<> %r28, %r25, %r0 2: stw %r24, 0(%r26) /* Free lock */ - stw,ma %r20, 0(%sr2,%r20) + sync + stw %r20, 0(%sr2,%r20) #if ENABLE_LWS_DEBUG /* Clear thread register indicator */ stw %r0, 4(%sr2,%r20) @@ -654,7 +655,8 @@ cas_action: 3: /* Error occurred on load or store */ /* Free lock */ - stw,ma %r20, 0(%sr2,%r20) + sync + stw %r20, 0(%sr2,%r20) #if ENABLE_LWS_DEBUG stw %r0, 4(%sr2,%r20) #endif @@ -855,7 +857,8 @@ cas2_action: cas2_end: /* Free lock */ - stw,ma %r20, 0(%sr2,%r20) + sync + stw %r20, 0(%sr2,%r20) /* Enable interrupts */ ssm PSW_SM_I, %r0 /* Return to userspace, set no error */ @@ -865,7 +868,8 @@ cas2_end: 22: /* Error occurred on load or store */ /* Free lock */ - stw,ma %r20, 0(%sr2,%r20) + sync + stw %r20, 0(%sr2,%r20) ssm PSW_SM_I, %r0 ldo 1(%r0),%r28 b lws_exit -- cgit From a87532c78d291265efadc4b20a8c7a70cd59ea29 Mon Sep 17 00:00:00 2001 From: "Steven Rostedt (VMware)" Date: Sun, 18 Nov 2018 17:27:43 -0500 Subject: parisc: function_graph: Simplify with function_graph_enter() The function_graph_enter() function does the work of calling the function graph hook function and the management of the shadow stack, simplifying the work done in the architecture dependent prepare_ftrace_return(). Have parisc use the new code, and remove the shadow stack management as well as having to set up the trace structure. This is needed to prepare for a fix of a design bug on how the curr_ret_stack is used. Cc: "James E.J. Bottomley" Cc: Helge Deller Cc: linux-parisc@vger.kernel.org Cc: stable@kernel.org Fixes: 03274a3ffb449 ("tracing/fgraph: Adjust fgraph depth before calling trace return callback") Reviewed-by: Masami Hiramatsu Signed-off-by: Steven Rostedt (VMware) --- arch/parisc/kernel/ftrace.c | 17 +++-------------- 1 file changed, 3 insertions(+), 14 deletions(-) (limited to 'arch/parisc') diff --git a/arch/parisc/kernel/ftrace.c b/arch/parisc/kernel/ftrace.c index 6fa8535d3cce..e46a4157a894 100644 --- a/arch/parisc/kernel/ftrace.c +++ b/arch/parisc/kernel/ftrace.c @@ -30,7 +30,6 @@ static void __hot prepare_ftrace_return(unsigned long *parent, unsigned long self_addr) { unsigned long old; - struct ftrace_graph_ent trace; extern int parisc_return_to_handler; if (unlikely(ftrace_graph_is_dead())) @@ -41,19 +40,9 @@ static void __hot prepare_ftrace_return(unsigned long *parent, old = *parent; - trace.func = self_addr; - trace.depth = current->curr_ret_stack + 1; - - /* Only trace if the calling function expects to */ - if (!ftrace_graph_entry(&trace)) - return; - - if (ftrace_push_return_trace(old, self_addr, &trace.depth, - 0, NULL) == -EBUSY) - return; - - /* activate parisc_return_to_handler() as return point */ - *parent = (unsigned long) &parisc_return_to_handler; + if (!function_graph_enter(old, self_addr, 0, NULL)) + /* activate parisc_return_to_handler() as return point */ + *parent = (unsigned long) &parisc_return_to_handler; } #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ -- cgit From 1e8249b8a4e960018e4baca6b523b8a4500af600 Mon Sep 17 00:00:00 2001 From: Helge Deller Date: Thu, 29 Nov 2018 17:05:47 +0100 Subject: parisc: Enable -ffunction-sections for modules on 32-bit kernel Frank Schreiner reported, that since kernel 4.18 he faces sysfs-warnings when loading modules on a 32-bit kernel. Here is one such example: sysfs: cannot create duplicate filename '/module/nfs/sections/.text' CPU: 0 PID: 98 Comm: modprobe Not tainted 4.18.0-2-parisc #1 Debian 4.18.10-2 Backtrace: [<1017ce2c>] show_stack+0x3c/0x50 [<107a7210>] dump_stack+0x28/0x38 [<103f900c>] sysfs_warn_dup+0x88/0xac [<103f8b1c>] sysfs_add_file_mode_ns+0x164/0x1d0 [<103f9e70>] internal_create_group+0x11c/0x304 [<103fa0a0>] sysfs_create_group+0x48/0x60 [<1022abe8>] load_module.constprop.35+0x1f9c/0x23b8 [<1022b278>] sys_finit_module+0xd0/0x11c [<101831dc>] syscall_exit+0x0/0x14 This warning gets triggered by the fact, that due to commit 24b6c22504a2 ("parisc: Build kernel without -ffunction-sections") we now get multiple .text sections in the kernel modules for which sysfs_create_group() can't create multiple virtual files. This patch works around the problem by re-enabling the -ffunction-sections compiler option for modules, while keeping it disabled for the non-module kernel code. Reported-by: Frank Scheiner Fixes: 24b6c22504a2 ("parisc: Build kernel without -ffunction-sections") Cc: # v4.18+ Signed-off-by: Helge Deller --- arch/parisc/Makefile | 7 +++++++ 1 file changed, 7 insertions(+) (limited to 'arch/parisc') diff --git a/arch/parisc/Makefile b/arch/parisc/Makefile index d047a09d660f..1085385e1f06 100644 --- a/arch/parisc/Makefile +++ b/arch/parisc/Makefile @@ -71,6 +71,13 @@ ifdef CONFIG_MLONGCALLS KBUILD_CFLAGS_KERNEL += -mlong-calls endif +# Without this, "ld -r" results in .text sections that are too big (> 0x40000) +# for branches to reach stubs. And multiple .text sections trigger a warning +# when creating the sysfs module information section. +ifndef CONFIG_64BIT +KBUILD_CFLAGS_MODULE += -ffunction-sections +endif + # select which processor to optimise for cflags-$(CONFIG_PA7000) += -march=1.1 -mschedule=7100 cflags-$(CONFIG_PA7200) += -march=1.1 -mschedule=7200 -- cgit