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Dynamic FTRACE for PA-RISC

PATCH Superseded Sven Schnelle 2 participants 9 messages Jun 4, 2019 – Jun 5, 2019

Subsystems (3)

v2 of 3 Superseded Latest is v3 →

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#0 lore raw

v2 cover Dynamic FTRACE for PA-RISC

Hi List,

this series adds support for dynamic ftrace. See the commit message of the patch for a explanation how it works. For testing, you need a patched version of gcc because the current version has a bug which misplaces the function label. John David Anglin can provide a patch which fixes this issue. This issue is tracked here: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=90751

Changes to v1:

- replace a few hardcoded size by sizeof()
- change len parameter of patch_text_multiple() to unsigned
- add link to gcc bugtracker

Sven Schnelle (6):
parisc: add support for patching multiple words
parisc: add spinlock to patch function
parisc: add WARN_ON() to clear_fixmap
parisc: use pr_debug() in kernel/module.c compiler.h: add CC_USING_PATCHABLE_FUNCTION_ENTRY
parisc: add dynamic ftrace

 arch/parisc/Kconfig               |   2 +
 arch/parisc/Makefile              |  18 +++++
 arch/parisc/include/asm/ftrace.h  |  15 +++-
 arch/parisc/include/asm/patch.h   |   4 +-
 arch/parisc/kernel/Makefile       |   9 ++-
 arch/parisc/kernel/entry.S        |  64 +++++++++++++++
 arch/parisc/kernel/ftrace.c       | 129 +++++++++++++++++++++++++++---
 arch/parisc/kernel/module.c       |  64 +++++++++------
 arch/parisc/kernel/module.lds     |   7 ++
 arch/parisc/kernel/patch.c        |  88 ++++++++++++++++----
 arch/parisc/kernel/vmlinux.lds.S  |   2 +
 arch/parisc/mm/fixmap.c           |   7 +-
 include/asm-generic/vmlinux.lds.h |   7 ++
 include/linux/compiler_types.h    |   2 +
 14 files changed, 358 insertions(+), 60 deletions(-)
 create mode 100644 arch/parisc/kernel/module.lds
Signature · 1 line
2.20.1
#1 lore raw

PATCH v2 1/6 parisc: add support for patching multiple words

add patch_text_multiple() which allows to patch multiple text words in memory. This can be used to copy functions.

---
 arch/parisc/include/asm/patch.h |  4 +-
 arch/parisc/kernel/patch.c      | 75 ++++++++++++++++++++++++++-------
 2 files changed, 62 insertions(+), 17 deletions(-)
arch/parisc/include/asm/patch.h +3 -1
index 685b58a13968..400d84c6e504 100644
@@ -4,8 +4,10 @@
 
 /* stop machine and patch kernel text */
 void patch_text(void *addr, unsigned int insn);
+void patch_text_multiple(void *addr, u32 *insn, unsigned int len);
 
 /* patch kernel text with machine already stopped (e.g. in kgdb) */
-void __patch_text(void *addr, unsigned int insn);
+void __patch_text(void *addr, u32 insn);
+void __patch_text_multiple(void *addr, u32 *insn, unsigned int len);
 
 #endif
arch/parisc/kernel/patch.c +59 -16

114 lines not on this page · raw message

Signature · 1 line
2.20.1
#2 lore raw

Re: [PATCH v2 1/6] parisc: add support for patching multiple words

arch/parisc/kernel/patch.c static void __kprobes patch_unmap(int fixmap) · line 67

Quoted 5 lines · Sven Schnelle
arch/parisc/kernel/patch.c +5 -0
+	while (len >= 4) {
+		*p++ = *insn++;
+		addr += sizeof(u32);
+		len -= sizeof(u32);
+		if (len && !((unsigned long)addr & ~PAGE_MASK)) {

if (len && offset_in_page(addr) == 0)

This is a bit more obvious to me. YMMV.

Eike

#3 lore raw

Re: [PATCH v2 1/6] parisc: add support for patching multiple words

Hi,

Quoted 10 lines · Rolf Eike Beer

arch/parisc/kernel/patch.c static void __kprobes patch_unmap(int fixmap) · line 67

Quoted 5 lines · Sven Schnelle
arch/parisc/kernel/patch.c +5 -0
+	while (len >= 4) {
+		*p++ = *insn++;
+		addr += sizeof(u32);
+		len -= sizeof(u32);
+		if (len && !((unsigned long)addr & ~PAGE_MASK)) {

if (len && offset_in_page(addr) == 0)

This is a bit more obvious to me. YMMV.

It is. I'll update the patch and send a v3. Thanks!

Sven

#4 lore raw

PATCH v2 2/6 parisc: add spinlock to patch function

In reply to Sven Schnelle

If multiple CPUs are patching code we need the spinlock to protect against parallel fixmap maps/unmap calls.

---
 arch/parisc/kernel/patch.c | 25 +++++++++++++++++++------
 1 file changed, 19 insertions(+), 6 deletions(-)
arch/parisc/kernel/patch.c +19 -6
index 624de41e0524..fb503f7ff60e 100644
@@ -23,7 +23,9 @@ struct patch {
 
 static DEFINE_RAW_SPINLOCK(patch_lock);
 
-static void __kprobes *patch_map(void *addr, int fixmap, int *need_unmap)
+static void __kprobes *patch_map(void *addr, int fixmap, unsigned long *flags,
+				 int *need_unmap)
+{
 	unsigned long uintaddr = (uintptr_t) addr;
 	bool module = !core_kernel_text(uintaddr);
 	struct page *page;
@@ -38,19 +40,29 @@ static void __kprobes *patch_map(void *addr, int fixmap, int *need_unmap)
 
 	*need_unmap = 1;
 	set_fixmap(fixmap, page_to_phys(page));
+	if (flags)
+		raw_spin_lock_irqsave(&patch_lock, *flags);
+	else
+		__acquire(&patch_lock);
 
 	return (void *) (__fix_to_virt(fixmap) + (uintaddr & ~PAGE_MASK));
 }
 
-static void __kprobes patch_unmap(int fixmap)
+static void __kprobes patch_unmap(int fixmap, unsigned long *flags)
 {
 	clear_fixmap(fixmap);
+
+	if (flags)
+		raw_spin_unlock_irqrestore(&patch_lock, *flags);
+	else
+		__release(&patch_lock);
 }
 
 void __kprobes __patch_text_multiple(void *addr, u32 *insn, unsigned int len)
 {
 	unsigned long start = (unsigned long)addr;
 	unsigned long end = (unsigned long)addr + len;
+	unsigned long flags;
 	u32 *p, *fixmap;
 	int mapped;
 
@@ -58,7 +70,7 @@ void __kprobes __patch_text_multiple(void *addr, u32 *insn, unsigned int len)
 	flush_kernel_vmap_range(addr, len);
 	flush_icache_range(start, end);
 
-	p = fixmap = patch_map(addr, FIX_TEXT_POKE0, &mapped);
+	p = fixmap = patch_map(addr, FIX_TEXT_POKE0, &flags, &mapped);
 
 	while (len >= 4) {
 		*p++ = *insn++;
@@ -72,14 +84,15 @@ void __kprobes __patch_text_multiple(void *addr, u32 *insn, unsigned int len)
 			flush_kernel_vmap_range((void *)fixmap,
 						(p-fixmap) * sizeof(*p));
 			if (mapped)
-				patch_unmap(FIX_TEXT_POKE0);
-			p = fixmap = patch_map(addr, FIX_TEXT_POKE0, &mapped);
+				patch_unmap(FIX_TEXT_POKE0, &flags);
+			p = fixmap = patch_map(addr, FIX_TEXT_POKE0, &flags,
+						&mapped);
 		}
 	}
 
 	flush_kernel_vmap_range((void *)fixmap, (p-fixmap) * sizeof(*p));
 	if (mapped)
-		patch_unmap(FIX_TEXT_POKE0);
+		patch_unmap(FIX_TEXT_POKE0, &flags);
 	flush_icache_range(start, end);
 }
 
Signature · 1 line
2.20.1
#5 lore raw

PATCH v2 3/6 parisc: add WARN_ON() to clear_fixmap

In reply to Sven Schnelle

Calling clear_fixmap() on an already cleared fixed mapping is a bad thing to do. Add a WARN_ON() to catch such issues.

---
 arch/parisc/mm/fixmap.c | 3 +++
 1 file changed, 3 insertions(+)
arch/parisc/mm/fixmap.c +3 -0
index c8d41b54fb19..36321bcd75ba 100644
@@ -35,6 +35,9 @@ void clear_fixmap(enum fixed_addresses idx)
 	pmd_t *pmd = pmd_offset(pgd, vaddr);
 	pte_t *pte = pte_offset_kernel(pmd, vaddr);
 
+	if (WARN_ON(pte_none(*pte)))
+		return;
+
 	pte_clear(&init_mm, vaddr, pte);
 
 	flush_tlb_kernel_range(vaddr, vaddr + PAGE_SIZE);
Signature · 1 line
2.20.1
#6 lore raw

PATCH v2 4/6 parisc: use pr_debug() in kernel/module.c

In reply to Sven Schnelle

Instead of using our own version, switch to the generic pr_() calls.

---
 arch/parisc/kernel/module.c | 44 ++++++++++++++++---------------------
 1 file changed, 19 insertions(+), 25 deletions(-)
arch/parisc/kernel/module.c +19 -25
index 43778420614b..3ff3b48df6e6 100644
@@ -48,9 +48,9 @@
  *	However, SEGREL32 is used only for PARISC unwind entries, and we want
  *	those entries to have an absolute address, and not just an offset.
  *
- *	The unwind table mechanism has the ability to specify an offset for 
+ *	The unwind table mechanism has the ability to specify an offset for
  *	the unwind table; however, because we split off the init functions into
- *	a different piece of memory, it is not possible to do this using a 
+ *	a different piece of memory, it is not possible to do this using a
  *	single offset. Instead, we use the above hack for now.
  */
 
@@ -68,12 +68,6 @@
 #include <asm/unwind.h>
 #include <asm/sections.h>
 
-#if 0
-#define DEBUGP printk
-#else
-#define DEBUGP(fmt...)
-#endif
-
 #define RELOC_REACHABLE(val, bits) \
 	(( ( !((val) & (1<<((bits)-1))) && ((val)>>(bits)) != 0 )  ||	\
 	     ( ((val) & (1<<((bits)-1))) && ((val)>>(bits)) != (((__typeof__(val))(~0))>>((bits)+2)))) ? \
@@ -315,7 +309,7 @@ unsigned int arch_mod_section_prepend(struct module *mod,
 		* sizeof(struct stub_entry);
 }
 
-#define CONST 
+#define CONST
 int module_frob_arch_sections(CONST Elf_Ehdr *hdr,
 			      CONST Elf_Shdr *sechdrs,
 			      CONST char *secstrings,
@@ -401,7 +395,7 @@ static Elf64_Word get_got(struct module *me, unsigned long value, long addend)
 
 	got[i].addr = value;
  out:
-	DEBUGP("GOT ENTRY %d[%x] val %lx\n", i, i*sizeof(struct got_entry),
+	pr_debug("GOT ENTRY %d[%lx] val %lx\n", i, i*sizeof(struct got_entry),
 	       value);
 	return i * sizeof(struct got_entry);
 }
@@ -554,7 +548,7 @@ int apply_relocate_add(Elf_Shdr *sechdrs,
 	//unsigned long dp = (unsigned long)$global$;
 	register unsigned long dp asm ("r27");
 
-	DEBUGP("Applying relocate section %u to %u\n", relsec,
+	pr_debug("Applying relocate section %u to %u\n", relsec,
 	       targetsec);
 	for (i = 0; i < sechdrs[relsec].sh_size / sizeof(*rel); i++) {
 		/* This is where to make the change */
@@ -578,7 +572,7 @@ int apply_relocate_add(Elf_Shdr *sechdrs,
 
 #if 0
 #define r(t) ELF32_R_TYPE(rel[i].r_info)==t ? #t :
-		DEBUGP("Symbol %s loc 0x%x val 0x%x addend 0x%x: %s\n",
+		pr_debug("Symbol %s loc 0x%x val 0x%x addend 0x%x: %s\n",
 			strtab + sym->st_name,
 			(uint32_t)loc, val, addend,
 			r(R_PARISC_PLABEL32)
@@ -619,7 +613,7 @@ int apply_relocate_add(Elf_Shdr *sechdrs,
 			/* See note about special handling of SEGREL32 at
 			 * the beginning of this file.
 			 */
-			*loc = fsel(val, addend); 
+			*loc = fsel(val, addend);
 			break;
 		case R_PARISC_SECREL32:
 			/* 32-bit section relative address. */
@@ -698,7 +692,7 @@ int apply_relocate_add(Elf_Shdr *sechdrs,
 	Elf_Addr loc0;
 	unsigned int targetsec = sechdrs[relsec].sh_info;
 
-	DEBUGP("Applying relocate section %u to %u\n", relsec,
+	pr_debug("Applying relocate section %u to %u\n", relsec,
 	       targetsec);
 	for (i = 0; i < sechdrs[relsec].sh_size / sizeof(*rel); i++) {
 		/* This is where to make the change */
@@ -740,7 +734,7 @@ int apply_relocate_add(Elf_Shdr *sechdrs,
 		case R_PARISC_LTOFF21L:
 			/* LT-relative; left 21 bits */
 			val = get_got(me, val, addend);
-			DEBUGP("LTOFF21L Symbol %s loc %p val %lx\n",
+			pr_debug("LTOFF21L Symbol %s loc %p val %llx\n",
 			       strtab + sym->st_name,
 			       loc, val);
 			val = lrsel(val, 0);
@@ -751,14 +745,14 @@ int apply_relocate_add(Elf_Shdr *sechdrs,
 			/* LT-relative; right 14 bits */
 			val = get_got(me, val, addend);
 			val = rrsel(val, 0);
-			DEBUGP("LTOFF14R Symbol %s loc %p val %lx\n",
+			pr_debug("LTOFF14R Symbol %s loc %p val %llx\n",
 			       strtab + sym->st_name,
 			       loc, val);
 			*loc = mask(*loc, 14) | reassemble_14(val);
 			break;
 		case R_PARISC_PCREL22F:
 			/* PC-relative; 22 bits */
-			DEBUGP("PCREL22F Symbol %s loc %p val %lx\n",
+			pr_debug("PCREL22F Symbol %s loc %p val %llx\n",
 			       strtab + sym->st_name,
 			       loc, val);
 			val += addend;
@@ -790,7 +784,7 @@ int apply_relocate_add(Elf_Shdr *sechdrs,
 					val = get_stub(me, val, addend, ELF_STUB_GOT,
 						       loc0, targetsec);
 			}
-			DEBUGP("STUB FOR %s loc %lx, val %lx+%lx at %lx\n", 
+			pr_debug("STUB FOR %s loc %px, val %llx+%llx at %llx\n",
 			       strtab + sym->st_name, loc, sym->st_value,
 			       addend, val);
 			val = (val - dot - 8)/4;
@@ -810,7 +804,7 @@ int apply_relocate_add(Elf_Shdr *sechdrs,
 			/* See note about special handling of SEGREL32 at
 			 * the beginning of this file.
 			 */
-			*loc = fsel(val, addend); 
+			*loc = fsel(val, addend);
 			break;
 		case R_PARISC_SECREL32:
 			/* 32-bit section relative address. */
@@ -820,14 +814,14 @@ int apply_relocate_add(Elf_Shdr *sechdrs,
 			/* 64-bit function address */
 			if(in_local(me, (void *)(val + addend))) {
 				*loc64 = get_fdesc(me, val+addend);
-				DEBUGP("FDESC for %s at %p points to %lx\n",
+				pr_debug("FDESC for %s at %llx points to %llx\n",
 				       strtab + sym->st_name, *loc64,
 				       ((Elf_Fdesc *)*loc64)->addr);
 			} else {
 				/* if the symbol is not local to this
 				 * module then val+addend is a pointer
 				 * to the function descriptor */
-				DEBUGP("Non local FPTR64 Symbol %s loc %p val %lx\n",
+				pr_debug("Non local FPTR64 Symbol %s loc %p val %llx\n",
 				       strtab + sym->st_name,
 				       loc, val);
 				*loc64 = val + addend;
@@ -858,7 +852,7 @@ register_unwind_table(struct module *me,
 	end = table + sechdrs[me->arch.unwind_section].sh_size;
 	gp = (Elf_Addr)me->core_layout.base + me->arch.got_offset;
 
-	DEBUGP("register_unwind_table(), sect = %d at 0x%p - 0x%p (gp=0x%lx)\n",
+	pr_debug("register_unwind_table(), sect = %d at 0x%p - 0x%p (gp=0x%lx)\n",
 	       me->arch.unwind_section, table, end, gp);
 	me->arch.unwind = unwind_table_add(me->name, 0, gp, table, end);
 }
@@ -914,7 +908,7 @@ int module_finalize(const Elf_Ehdr *hdr,
 		}
 	}
 
-	DEBUGP("module %s: strtab %p, symhdr %p\n",
+	pr_debug("module %s: strtab %p, symhdr %p\n",
 	       me->name, strtab, symhdr);
 
 	if(me->arch.got_count > MAX_GOTS) {
@@ -933,7 +927,7 @@ int module_finalize(const Elf_Ehdr *hdr,
 	oldptr = (void *)symhdr->sh_addr;
 	newptr = oldptr + 1;	/* we start counting at 1 */
 	nsyms = symhdr->sh_size / sizeof(Elf_Sym);
-	DEBUGP("OLD num_symtab %lu\n", nsyms);
+	pr_debug("OLD num_symtab %lu\n", nsyms);
 
 	for (i = 1; i < nsyms; i++) {
 		oldptr++;	/* note, count starts at 1 so preincrement */
@@ -948,7 +942,7 @@ int module_finalize(const Elf_Ehdr *hdr,
 
 	}
 	nsyms = newptr - (Elf_Sym *)symhdr->sh_addr;
-	DEBUGP("NEW num_symtab %lu\n", nsyms);
+	pr_debug("NEW num_symtab %lu\n", nsyms);
 	symhdr->sh_size = nsyms * sizeof(Elf_Sym);
 
 	/* find .altinstructions section */
Signature · 1 line
2.20.1
#7 lore raw

PATCH v2 5/6 compiler.h: add CC_USING_PATCHABLE_FUNCTION_ENTRY

In reply to Sven Schnelle

This can be used for architectures implementing dynamic ftrace via -fpatchable-function-entry.

---
 include/linux/compiler_types.h | 2 ++
 1 file changed, 2 insertions(+)
include/linux/compiler_types.h +2 -0
index 19e58b9138a0..095d55c3834d 100644
@@ -112,6 +112,8 @@ struct ftrace_likely_data {
 
 #if defined(CC_USING_HOTPATCH)
 #define notrace			__attribute__((hotpatch(0, 0)))
+#elif defined(CC_USING_PATCHABLE_FUNCTION_ENTRY)
+#define notrace			__attribute__((patchable_function_entry(0, 0)))
 #else
 #define notrace			__attribute__((__no_instrument_function__))
 #endif
Signature · 1 line
2.20.1
#8 lore raw

PATCH v2 6/6 parisc: add dynamic ftrace

In reply to Sven Schnelle

This patch implements dynamic ftrace for PA-RISC. The required mcount call sequences can get pretty long, so instead of patching the whole call sequence out of the functions, we are using -fpatchable-function-entry from gcc. This puts a configurable amount of NOPS before/at the start of the function. Taking do_sys_open() as example, which would look like this when the call is patched out:

1036b248:       08 00 02 40     nop
1036b24c:       08 00 02 40     nop
1036b250:       08 00 02 40     nop
1036b254:       08 00 02 40     nop

1036b258 <do_sys_open>:

1036b258:       08 00 02 40     nop
1036b25c:       08 03 02 41     copy r3,r1
1036b260:       6b c2 3f d9     stw rp,-14(sp)
1036b264:       08 1e 02 43     copy sp,r3
1036b268:       6f c1 01 00     stw,ma r1,80(sp)

When ftrace gets enabled for this function the kernel will patch these NOPs to:

1036b248:       10 19 57 20     <address of ftrace>
1036b24c:       6f c1 00 80     stw,ma r1,40(sp)
1036b250:       48 21 3f d1     ldw -18(r1),r1
1036b254:       e8 20 c0 02     bv,n r0(r1)

1036b258 <do_sys_open>:

1036b258:       e8 3f 1f df     b,l,n .-c,r1
1036b25c:       08 03 02 41     copy r3,r1
1036b260:       6b c2 3f d9     stw rp,-14(sp)
1036b264:       08 1e 02 43     copy sp,r3
1036b268:       6f c1 01 00     stw,ma r1,80(sp)

So the first NOP in do_sys_open() will be patched to jump backwards into some minimal trampoline code which pushes a stackframe, saves r1 which holds the return address, loads the address of the real ftrace function, and branches to that location. For 64 Bit things are getting a bit more complicated (and longer) because we must make sure that the address of ftrace location is 8 byte aligned, and the offset passed to ldd for fetching the address is 8 byte aligned as well.

Note that gcc has a bug which misplaces the function label, and needs a patch to make dynamic ftrace work. See
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=90751 for details.

---
 arch/parisc/Kconfig               |   2 +
 arch/parisc/Makefile              |  18 +++++
 arch/parisc/include/asm/ftrace.h  |  15 +++-
 arch/parisc/kernel/Makefile       |   9 ++-
 arch/parisc/kernel/entry.S        |  64 +++++++++++++++
 arch/parisc/kernel/ftrace.c       | 129 +++++++++++++++++++++++++++---
 arch/parisc/kernel/module.c       |  20 ++++-
 arch/parisc/kernel/module.lds     |   7 ++
 arch/parisc/kernel/vmlinux.lds.S  |   2 +
 arch/parisc/mm/fixmap.c           |   4 +-
 include/asm-generic/vmlinux.lds.h |   7 ++
 11 files changed, 259 insertions(+), 18 deletions(-)
 create mode 100644 arch/parisc/kernel/module.lds
arch/parisc/Kconfig +2 -0
index 4860efa91d7b..42875ff15671 100644
@@ -59,6 +59,8 @@ config PARISC
 	select HAVE_ARCH_KGDB
 	select HAVE_KPROBES
 	select HAVE_KRETPROBES
+	select HAVE_DYNAMIC_FTRACE if $(cc-option,-fpatchable-function-entry=1,1)
+	select HAVE_FTRACE_MCOUNT_RECORD if HAVE_DYNAMIC_FTRACE
 
 	help
 	  The PA-RISC microprocessor is designed by Hewlett-Packard and used
arch/parisc/Makefile +18 -0
index c19af26febe6..58d46665cad9 100644
@@ -47,6 +47,24 @@ ifneq ($(SUBARCH),$(UTS_MACHINE))
 	endif
 endif
 
+ifdef CONFIG_DYNAMIC_FTRACE
+ifdef CONFIG_64BIT
+NOP_COUNT := 8
+else
+NOP_COUNT := 5
+endif
+
+export CC_USING_RECORD_MCOUNT:=1
+export CC_USING_PATCHABLE_FUNCTION_ENTRY:=1
+
+KBUILD_AFLAGS += -DCC_USING_PATCHABLE_FUNCTION_ENTRY=1
+KBUILD_CFLAGS += -DCC_USING_PATCHABLE_FUNCTION_ENTRY=1 \
+		 -DFTRACE_PATCHABLE_FUNCTION_SIZE=$(NOP_COUNT)
+
+CC_FLAGS_FTRACE := -fpatchable-function-entry=$(NOP_COUNT),$(shell echo $$(($(NOP_COUNT)-1)))
+KBUILD_LDFLAGS_MODULE += -T $(srctree)/arch/parisc/kernel/module.lds
+endif
+
 OBJCOPY_FLAGS =-O binary -R .note -R .comment -S
 
 cflags-y	:= -pipe
arch/parisc/include/asm/ftrace.h +13 -2
index 42b2c75a1645..958c0aa5dbb2 100644
@@ -5,12 +5,23 @@
 #ifndef __ASSEMBLY__
 extern void mcount(void);
 
-#define MCOUNT_INSN_SIZE 4
-
+#define MCOUNT_ADDR		((unsigned long)mcount)
+#define MCOUNT_INSN_SIZE	4
+#define CC_USING_NOP_MCOUNT
 extern unsigned long sys_call_table[];
 
 extern unsigned long return_address(unsigned int);
 
+#ifdef CONFIG_DYNAMIC_FTRACE
+extern void ftrace_caller(void);
+
+struct dyn_arch_ftrace {
+};
+
+unsigned long ftrace_call_adjust(unsigned long addr);
+
+#endif
+
 #define ftrace_return_address(n) return_address(n)
 
 #endif /* __ASSEMBLY__ */
arch/parisc/kernel/Makefile +5 -4
index fc0df5c44468..c232266b517c 100644
@@ -14,10 +14,11 @@ obj-y	     	:= cache.o pacache.o setup.o pdt.o traps.o time.o irq.o \
 
 ifdef CONFIG_FUNCTION_TRACER
 # Do not profile debug and lowlevel utilities
-CFLAGS_REMOVE_ftrace.o = -pg
-CFLAGS_REMOVE_cache.o = -pg
-CFLAGS_REMOVE_perf.o = -pg
-CFLAGS_REMOVE_unwind.o = -pg
+CFLAGS_REMOVE_ftrace.o = $(CC_FLAGS_FTRACE)
+CFLAGS_REMOVE_cache.o =  $(CC_FLAGS_FTRACE)
+CFLAGS_REMOVE_perf.o = $(CC_FLAGS_FTRACE)
+CFLAGS_REMOVE_unwind.o = $(CC_FLAGS_FTRACE)
+CFLAGS_REMOVE_patch.o = $(CC_FLAGS_FTRACE)
 endif
 
 obj-$(CONFIG_SMP)	+= smp.o
arch/parisc/kernel/entry.S +64 -0

70 lines not on this page · raw message

arch/parisc/kernel/ftrace.c +120 -9

153 lines not on this page · raw message

arch/parisc/kernel/module.c +19 -1
index 3ff3b48df6e6..ed6640527534 100644
@@ -873,6 +873,7 @@ int module_finalize(const Elf_Ehdr *hdr,
 	const char *strtab = NULL;
 	const Elf_Shdr *s;
 	char *secstrings;
+	int err, symindex = -1;
 	Elf_Sym *newptr, *oldptr;
 	Elf_Shdr *symhdr = NULL;
 #ifdef DEBUG
@@ -899,6 +900,7 @@ int module_finalize(const Elf_Ehdr *hdr,
 		if(sechdrs[i].sh_type == SHT_SYMTAB
 		   && (sechdrs[i].sh_flags & SHF_ALLOC)) {
 			int strindex = sechdrs[i].sh_link;
+			symindex = i;
 			/* FIXME: AWFUL HACK
 			 * The cast is to drop the const from
 			 * the sechdrs pointer */
@@ -954,8 +956,24 @@ int module_finalize(const Elf_Ehdr *hdr,
 		if (!strcmp(".altinstructions", secname))
 			/* patch .altinstructions */
 			apply_alternatives(aseg, aseg + s->sh_size, me->name);
-	}
 
+		/* For 32 bit kernels we're compiling modules with
+		 * -ffunction-sections so we must relocate the addresses in the
+		 *__mcount_loc section.
+		 */
+		if (symindex != -1 && !strcmp(secname, "__mcount_loc")) {
+			if (s->sh_type == SHT_REL)
+				err = apply_relocate((Elf_Shdr *)sechdrs,
+							strtab, symindex,
+							s - sechdrs, me);
+			else if (s->sh_type == SHT_RELA)
+				err = apply_relocate_add((Elf_Shdr *)sechdrs,
+							strtab, symindex,
+							s - sechdrs, me);
+			if (err)
+				return err;
+		}
+	}
 	return 0;
 }
 
arch/parisc/kernel/module.lds new file +7 -0
new file mode 100644
index 000000000000..1a9a92aca5c8
@@ -0,0 +1,7 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+SECTIONS {
+	__mcount_loc : {
+		*(__patchable_function_entries)
+	}
+}
arch/parisc/kernel/vmlinux.lds.S +2 -0
index cd33b4feacb1..99cd24f2ea01 100644
@@ -18,6 +18,8 @@
 				*(.data..vm0.pgd) \
 				*(.data..vm0.pte)
 
+#define CC_USING_PATCHABLE_FUNCTION_ENTRY
+
 #include <asm-generic/vmlinux.lds.h>
 
 /* needed for the processor specific cache alignment size */	
arch/parisc/mm/fixmap.c +2 -2
index 36321bcd75ba..474cd241c150 100644
@@ -10,7 +10,7 @@
 #include <asm/cacheflush.h>
 #include <asm/fixmap.h>
 
-void set_fixmap(enum fixed_addresses idx, phys_addr_t phys)
+void notrace set_fixmap(enum fixed_addresses idx, phys_addr_t phys)
 {
 	unsigned long vaddr = __fix_to_virt(idx);
 	pgd_t *pgd = pgd_offset_k(vaddr);
@@ -28,7 +28,7 @@ void set_fixmap(enum fixed_addresses idx, phys_addr_t phys)
 	flush_tlb_kernel_range(vaddr, vaddr + PAGE_SIZE);
 }
 
-void clear_fixmap(enum fixed_addresses idx)
+void notrace clear_fixmap(enum fixed_addresses idx)
 {
 	unsigned long vaddr = __fix_to_virt(idx);
 	pgd_t *pgd = pgd_offset_k(vaddr);
include/asm-generic/vmlinux.lds.h +7 -0
index 088987e9a3ea..ca42182992a5 100644
@@ -110,10 +110,17 @@
 #endif
 
 #ifdef CONFIG_FTRACE_MCOUNT_RECORD
+#ifdef CC_USING_PATCHABLE_FUNCTION_ENTRY
+#define MCOUNT_REC()	. = ALIGN(8);				\
+			__start_mcount_loc = .;			\
+			KEEP(*(__patchable_function_entries))	\
+			__stop_mcount_loc = .;
+#else
 #define MCOUNT_REC()	. = ALIGN(8);				\
 			__start_mcount_loc = .;			\
 			KEEP(*(__mcount_loc))			\
 			__stop_mcount_loc = .;
+#endif
 #else
 #define MCOUNT_REC()
 #endif
Signature · 1 line
2.20.1