From f25f9074c24f1451a74942c4bc089bb53e47f462 Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Sat, 7 Feb 2009 20:22:40 +0000 Subject: powerpc/ftrace: Fix math to calculate offset in TOC Impact: fix dynamic ftrace with large modules in PPC64 The math to calculate the offset into the TOC that is taken from reading the trampoline is incorrect. The bottom half of the offset is a signed extended short. The current code was using an OR to create the offset when it should have been using an addition. Signed-off-by: Steven Rostedt Acked-by: Geoff Levand Signed-off-by: Benjamin Herrenschmidt --- arch/powerpc/kernel/ftrace.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) (limited to 'arch/powerpc/kernel') diff --git a/arch/powerpc/kernel/ftrace.c b/arch/powerpc/kernel/ftrace.c index 5355244c99ff..60c60ccf5e3c 100644 --- a/arch/powerpc/kernel/ftrace.c +++ b/arch/powerpc/kernel/ftrace.c @@ -195,8 +195,9 @@ __ftrace_make_nop(struct module *mod, return -EINVAL; } - offset = (unsigned)((unsigned short)jmp[0]) << 16 | - (unsigned)((unsigned short)jmp[1]); + /* The bottom half is signed extended */ + offset = ((unsigned)((unsigned short)jmp[0]) << 16) + + (int)((short)jmp[1]); DEBUGP(" %x ", offset); -- cgit v1.2.2 From 5b11abfdb572bf9284e596dd198ac2aaf95b6616 Mon Sep 17 00:00:00 2001 From: Benjamin Herrenschmidt Date: Sun, 8 Feb 2009 14:27:21 +0000 Subject: powerpc/pci: mmap anonymous memory when legacy_mem doesn't exist The new legacy_mem file in sysfs is causing problems with X on machines that don't support legacy memory access. The way I initially implemented it, we would fail with -ENXIO when trying to mmap it, thus exposing to X that we do support the API but there is no legacy memory. Unfortunately, X poor error handling is causing it to fail to start when it gets this error. This implements a workaround hack that instead maps anonymous memory instead (using shmem if VM_SHARED is set, just like /dev/zero does). Signed-off-by: Benjamin Herrenschmidt --- arch/powerpc/kernel/pci-common.c | 17 +++++++++++++++-- 1 file changed, 15 insertions(+), 2 deletions(-) (limited to 'arch/powerpc/kernel') diff --git a/arch/powerpc/kernel/pci-common.c b/arch/powerpc/kernel/pci-common.c index 19b12d2cbb4b..0f4181272311 100644 --- a/arch/powerpc/kernel/pci-common.c +++ b/arch/powerpc/kernel/pci-common.c @@ -561,8 +561,21 @@ int pci_mmap_legacy_page_range(struct pci_bus *bus, (unsigned long long)(offset + size - 1)); if (mmap_state == pci_mmap_mem) { - if ((offset + size) > hose->isa_mem_size) - return -ENXIO; + /* Hack alert ! + * + * Because X is lame and can fail starting if it gets an error trying + * to mmap legacy_mem (instead of just moving on without legacy memory + * access) we fake it here by giving it anonymous memory, effectively + * behaving just like /dev/zero + */ + if ((offset + size) > hose->isa_mem_size) { + printk(KERN_DEBUG + "Process %s (pid:%d) mapped non-existing PCI legacy memory for 0%04x:%02x\n", + current->comm, current->pid, pci_domain_nr(bus), bus->number); + if (vma->vm_flags & VM_SHARED) + return shmem_zero_setup(vma); + return 0; + } offset += hose->isa_mem_phys; } else { unsigned long io_offset = (unsigned long)hose->io_base_virt - _IO_BASE; -- cgit v1.2.2