From fb20f65a01a97bdf4bb746eecfc24a08561e2648 Mon Sep 17 00:00:00 2001 From: Olaf Hering Date: Fri, 20 Oct 2006 15:57:15 +0200 Subject: [POWERPC] Fix hang in start_ldr if _end or _edata is unaligned Quick fix for lack of memset(__bss_start, 0, _end-__bss_start) in load_kernel(). If edata is unaligned, the loop will overwrite all memory because r3 and r4 will never be equal. Signed-off-by: Olaf Hering Signed-off-by: Paul Mackerras --- arch/ppc/boot/simple/relocate.S | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) (limited to 'arch/ppc') diff --git a/arch/ppc/boot/simple/relocate.S b/arch/ppc/boot/simple/relocate.S index 0c02155..1bbbcd2 100644 --- a/arch/ppc/boot/simple/relocate.S +++ b/arch/ppc/boot/simple/relocate.S @@ -154,8 +154,8 @@ do_relocate_out: start_ldr: /* Clear all of BSS and set up stack for C calls */ - lis r3,edata@h - ori r3,r3,edata@l + lis r3,__bss_start@h + ori r3,r3,__bss_start@l lis r4,end@h ori r4,r4,end@l subi r3,r3,4 @@ -163,7 +163,7 @@ start_ldr: li r0,0 50: stwu r0,4(r3) cmpw cr0,r3,r4 - bne 50b + blt 50b 90: mr r9,r1 /* Save old stack pointer (in case it matters) */ lis r1,.stack@h ori r1,r1,.stack@l -- cgit v1.1 From 42c4aaadb737e0e672b3fb86b2c41ff59f0fb8bc Mon Sep 17 00:00:00 2001 From: Benjamin Herrenschmidt Date: Tue, 24 Oct 2006 16:42:40 +1000 Subject: [POWERPC] Consolidate feature fixup code There are currently two versions of the functions for applying the feature fixups, one for CPU features and one for firmware features. In addition, they are both in assembly and with separate implementations for 32 and 64 bits. identify_cpu() is also implemented in assembly and separately for 32 and 64 bits. This patch replaces them with a pair of C functions. The call sites are slightly moved on ppc64 as well to be called from C instead of from assembly, though it's a very small change, and thus shouldn't cause any problem. Signed-off-by: Benjamin Herrenschmidt Acked-by: Olof Johansson Signed-off-by: Paul Mackerras --- arch/ppc/kernel/misc.S | 74 ------------------------------------------------- arch/ppc/kernel/setup.c | 10 ++++--- 2 files changed, 6 insertions(+), 78 deletions(-) (limited to 'arch/ppc') diff --git a/arch/ppc/kernel/misc.S b/arch/ppc/kernel/misc.S index 5f66840..d319f9b 100644 --- a/arch/ppc/kernel/misc.S +++ b/arch/ppc/kernel/misc.S @@ -110,80 +110,6 @@ _GLOBAL(reloc_got2) blr /* - * identify_cpu, - * called with r3 = data offset and r4 = CPU number - * doesn't change r3 - */ -_GLOBAL(identify_cpu) - addis r8,r3,cpu_specs@ha - addi r8,r8,cpu_specs@l - mfpvr r7 -1: - lwz r5,CPU_SPEC_PVR_MASK(r8) - and r5,r5,r7 - lwz r6,CPU_SPEC_PVR_VALUE(r8) - cmplw 0,r6,r5 - beq 1f - addi r8,r8,CPU_SPEC_ENTRY_SIZE - b 1b -1: - addis r6,r3,cur_cpu_spec@ha - addi r6,r6,cur_cpu_spec@l - sub r8,r8,r3 - stw r8,0(r6) - blr - -/* - * do_cpu_ftr_fixups - goes through the list of CPU feature fixups - * and writes nop's over sections of code that don't apply for this cpu. - * r3 = data offset (not changed) - */ -_GLOBAL(do_cpu_ftr_fixups) - /* Get CPU 0 features */ - addis r6,r3,cur_cpu_spec@ha - addi r6,r6,cur_cpu_spec@l - lwz r4,0(r6) - add r4,r4,r3 - lwz r4,CPU_SPEC_FEATURES(r4) - - /* Get the fixup table */ - addis r6,r3,__start___ftr_fixup@ha - addi r6,r6,__start___ftr_fixup@l - addis r7,r3,__stop___ftr_fixup@ha - addi r7,r7,__stop___ftr_fixup@l - - /* Do the fixup */ -1: cmplw 0,r6,r7 - bgelr - addi r6,r6,16 - lwz r8,-16(r6) /* mask */ - and r8,r8,r4 - lwz r9,-12(r6) /* value */ - cmplw 0,r8,r9 - beq 1b - lwz r8,-8(r6) /* section begin */ - lwz r9,-4(r6) /* section end */ - subf. r9,r8,r9 - beq 1b - /* write nops over the section of code */ - /* todo: if large section, add a branch at the start of it */ - srwi r9,r9,2 - mtctr r9 - add r8,r8,r3 - lis r0,0x60000000@h /* nop */ -3: stw r0,0(r8) - andi. r10,r4,CPU_FTR_SPLIT_ID_CACHE@l - beq 2f - dcbst 0,r8 /* suboptimal, but simpler */ - sync - icbi 0,r8 -2: addi r8,r8,4 - bdnz 3b - sync /* additional sync needed on g4 */ - isync - b 1b - -/* * call_setup_cpu - call the setup_cpu function for this cpu * r3 = data offset, r24 = cpu number * diff --git a/arch/ppc/kernel/setup.c b/arch/ppc/kernel/setup.c index 75fe138..41a640f 100644 --- a/arch/ppc/kernel/setup.c +++ b/arch/ppc/kernel/setup.c @@ -38,6 +38,7 @@ #include #include #include +#include #define USES_PPC_SYS (defined(CONFIG_85xx) || defined(CONFIG_83xx) || \ defined(CONFIG_MPC10X_BRIDGE) || defined(CONFIG_8260) || \ @@ -53,8 +54,6 @@ extern void platform_init(unsigned long r3, unsigned long r4, unsigned long r5, unsigned long r6, unsigned long r7); -extern void identify_cpu(unsigned long offset, unsigned long cpu); -extern void do_cpu_ftr_fixups(unsigned long offset); extern void reloc_got2(unsigned long offset); extern void ppc6xx_idle(void); @@ -301,6 +300,7 @@ early_init(int r3, int r4, int r5) { unsigned long phys; unsigned long offset = reloc_offset(); + struct cpu_spec *spec; /* Default */ phys = offset + KERNELBASE; @@ -313,8 +313,10 @@ early_init(int r3, int r4, int r5) * Identify the CPU type and fix up code sections * that depend on which cpu we have. */ - identify_cpu(offset, 0); - do_cpu_ftr_fixups(offset); + spec = identify_cpu(offset); + do_feature_fixups(offset, spec->cpu_features, + PTRRELOC(&__start___ftr_fixup), + PTRRELOC(&__stop___ftr_fixup)); return phys; } -- cgit v1.1 From 0909c8c2d547e45ca50e2492b08ec93a37b35237 Mon Sep 17 00:00:00 2001 From: Benjamin Herrenschmidt Date: Fri, 20 Oct 2006 11:47:18 +1000 Subject: [POWERPC] Support feature fixups in vdso's This patch reworks the feature fixup mecanism so vdso's can be fixed up. The main issue was that the construct: .long label (or .llong on 64 bits) will not work in the case of a shared library like the vdso. It will generate an empty placeholder in the fixup table along with a reloc, which is not something we can deal with in the vdso. The idea here (thanks Alan Modra !) is to instead use something like: 1: .long label - 1b That is, the feature fixup tables no longer contain addresses of bits of code to patch, but offsets of such code from the fixup table entry itself. That is properly resolved by ld when building the .so's. I've modified the fixup mecanism generically to use that method for the rest of the kernel as well. Another trick is that the 32 bits vDSO included in the 64 bits kernel need to have a table in the 64 bits format. However, gas does not support 32 bits code with a statement of the form: .llong label - 1b (Or even just .llong label) That is, it cannot emit the right fixup/relocation for the linker to use to assign a 32 bits address to an .llong field. Thus, in the specific case of the 32 bits vdso built as part of the 64 bits kernel, we are using a modified macro that generates: .long 0xffffffff .llong label - 1b Note that is assumes that the value is negative which is enforced by the .lds (those offsets are always negative as the .text is always before the fixup table and gas doesn't support emiting the reloc the other way around). Signed-off-by: Benjamin Herrenschmidt Signed-off-by: Paul Mackerras --- arch/ppc/kernel/setup.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'arch/ppc') diff --git a/arch/ppc/kernel/setup.c b/arch/ppc/kernel/setup.c index 41a640f..27faeca 100644 --- a/arch/ppc/kernel/setup.c +++ b/arch/ppc/kernel/setup.c @@ -314,7 +314,7 @@ early_init(int r3, int r4, int r5) * that depend on which cpu we have. */ spec = identify_cpu(offset); - do_feature_fixups(offset, spec->cpu_features, + do_feature_fixups(spec->cpu_features, PTRRELOC(&__start___ftr_fixup), PTRRELOC(&__stop___ftr_fixup)); -- cgit v1.1 From 61ce1efe6e40233663d27ab8ac9ba9710eebcaad Mon Sep 17 00:00:00 2001 From: Andrew Morton Date: Fri, 27 Oct 2006 11:41:44 -0700 Subject: [PATCH] vmlinux.lds: consolidate initcall sections Add a vmlinux.lds.h helper macro for defining the eight-level initcall table, teach all the architectures to use it. This is a prerequisite for a patch which performs initcall synchronisation for multithreaded-probing. Cc: Greg KH Signed-off-by: Andrew Morton [ Added AVR32 as well ] Signed-off-by: Haavard Skinnemoen Signed-off-by: Linus Torvalds --- arch/ppc/kernel/vmlinux.lds.S | 8 +------- 1 file changed, 1 insertion(+), 7 deletions(-) (limited to 'arch/ppc') diff --git a/arch/ppc/kernel/vmlinux.lds.S b/arch/ppc/kernel/vmlinux.lds.S index 095fd33..16e8661 100644 --- a/arch/ppc/kernel/vmlinux.lds.S +++ b/arch/ppc/kernel/vmlinux.lds.S @@ -115,13 +115,7 @@ SECTIONS __setup_end = .; __initcall_start = .; .initcall.init : { - *(.initcall1.init) - *(.initcall2.init) - *(.initcall3.init) - *(.initcall4.init) - *(.initcall5.init) - *(.initcall6.init) - *(.initcall7.init) + INITCALLS } __initcall_end = .; -- cgit v1.1 From 4393c4f6788cee65095dd838cfeca6edefbfeb52 Mon Sep 17 00:00:00 2001 From: Benjamin Herrenschmidt Date: Wed, 1 Nov 2006 15:11:39 +1100 Subject: [POWERPC] Make alignment exception always check exception table The alignment exception used to only check the exception table for -EFAULT, not for other errors. That opens an oops window if we can coerce the kernel into getting an alignment exception for other reasons in what would normally be a user-protected accessor, which can be done via some of the futex ops. This fixes it by always checking the exception tables. Signed-off-by: Benjamin Herrenschmidt Signed-off-by: Paul Mackerras --- arch/ppc/kernel/traps.c | 18 ++++++++++-------- 1 file changed, 10 insertions(+), 8 deletions(-) (limited to 'arch/ppc') diff --git a/arch/ppc/kernel/traps.c b/arch/ppc/kernel/traps.c index aafc8e8..9661a91 100644 --- a/arch/ppc/kernel/traps.c +++ b/arch/ppc/kernel/traps.c @@ -708,7 +708,7 @@ void single_step_exception(struct pt_regs *regs) void alignment_exception(struct pt_regs *regs) { - int fixed; + int sig, code, fixed = 0; fixed = fix_alignment(regs); if (fixed == 1) { @@ -717,14 +717,16 @@ void alignment_exception(struct pt_regs *regs) return; } if (fixed == -EFAULT) { - /* fixed == -EFAULT means the operand address was bad */ - if (user_mode(regs)) - _exception(SIGSEGV, regs, SEGV_ACCERR, regs->dar); - else - bad_page_fault(regs, regs->dar, SIGSEGV); - return; + sig = SIGSEGV; + code = SEGV_ACCERR; + } else { + sig = SIGBUS; + code = BUS_ADRALN; } - _exception(SIGBUS, regs, BUS_ADRALN, regs->dar); + if (user_mode(regs)) + _exception(sig, regs, code, regs->dar); + else + bad_page_fault(regs, regs->dar, sig); } void StackOverflow(struct pt_regs *regs) -- cgit v1.1