From: Ingo Molnar <mingo@kernel.org>
To: Linus Torvalds <torvalds@linux-foundation.org>
Cc: linux-kernel@vger.kernel.org,
Peter Zijlstra <a.p.zijlstra@chello.nl>,
Arnaldo Carvalho de Melo <acme@infradead.org>,
Oleg Nesterov <oleg@redhat.com>,
Thomas Gleixner <tglx@linutronix.de>,
Andrew Morton <akpm@linux-foundation.org>
Subject: [GIT PULL] perf fixes
Date: Tue, 23 Oct 2012 13:02:07 +0200 [thread overview]
Message-ID: <20121023110207.GA28324@gmail.com> (raw)
Linus,
Please pull the latest perf-urgent-for-linus git tree from:
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git perf-urgent-for-linus
HEAD: ef8ff74ed8dd9d4b3ba8cb9f2fc927a27c697a8b Merge branch 'tip/perf/urgent' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace into perf/urgent
Most of these are uprobes race fixes from Oleg, and their
preparatory cleanups. (It's larger than what I'd normally send
for an -rc kernel, but they looked significant enough to not
delay them.)
There's also an oprofile fix and an uncore PMU fix.
Thanks,
Ingo
------------------>
Dan Carpenter (1):
oprofile, x86: Fix wrapping bug in op_x86_get_ctrl()
Oleg Nesterov (19):
uprobes: Do not leak UTASK_BP_HIT if find_active_uprobe() fails
uprobes: Do not setup ->active_uprobe/state prematurely
uprobes: Fix UPROBE_SKIP_SSTEP checks in handle_swbp()
uprobes: Kill UTASK_BP_HIT state
uprobes: Move clear_thread_flag(TIF_UPROBE) to uprobe_notify_resume()
uprobes: Change write_opcode() to use FOLL_FORCE
uprobes: Change valid_vma() to demand VM_MAYEXEC rather than VM_EXEC
uprobes: Restrict valid_vma(false) to skip VM_SHARED vmas
uprobes: Kill set_swbp()->is_swbp_at_addr()
uprobes: Introduce copy_opcode(), kill read_opcode()
uprobes: Kill set_orig_insn()->is_swbp_at_addr()
uprobes: Simplify is_swbp_at_addr(), remove stale comments
uprobes/x86: Only rep+nop can be emulated correctly
uprobes: Don't return success if alloc_uprobe() fails
uprobes: Do not delete uprobe if uprobe_unregister() fails
uprobes: Fix handle_swbp() vs unregister() + register() race
uprobes: Introduce prepare_uprobe()
uprobes: Fix prepare_uprobe() race with itself
uprobes: Fix the racy uprobe->flags manipulation
Vaibhav Nagarnaik (1):
ring-buffer: Check for uninitialized cpu buffer before resizing
Yan, Zheng (1):
perf/x86: Disable uncore on virtualized CPUs
arch/x86/kernel/cpu/perf_event_intel_uncore.c | 3 +
arch/x86/kernel/signal.c | 4 +-
arch/x86/kernel/uprobes.c | 16 +-
arch/x86/oprofile/nmi_int.c | 2 +-
include/linux/uprobes.h | 11 -
kernel/events/uprobes.c | 345 ++++++++++++--------------
kernel/trace/ring_buffer.c | 4 +
7 files changed, 173 insertions(+), 212 deletions(-)
diff --git a/arch/x86/kernel/cpu/perf_event_intel_uncore.c b/arch/x86/kernel/cpu/perf_event_intel_uncore.c
index 99d96a4..5df8d32 100644
--- a/arch/x86/kernel/cpu/perf_event_intel_uncore.c
+++ b/arch/x86/kernel/cpu/perf_event_intel_uncore.c
@@ -2926,6 +2926,9 @@ static int __init intel_uncore_init(void)
if (boot_cpu_data.x86_vendor != X86_VENDOR_INTEL)
return -ENODEV;
+ if (cpu_has_hypervisor)
+ return -ENODEV;
+
ret = uncore_pci_init();
if (ret)
goto fail;
diff --git a/arch/x86/kernel/signal.c b/arch/x86/kernel/signal.c
index 29ad351..70b27ee 100644
--- a/arch/x86/kernel/signal.c
+++ b/arch/x86/kernel/signal.c
@@ -824,10 +824,8 @@ do_notify_resume(struct pt_regs *regs, void *unused, __u32 thread_info_flags)
mce_notify_process();
#endif /* CONFIG_X86_64 && CONFIG_X86_MCE */
- if (thread_info_flags & _TIF_UPROBE) {
- clear_thread_flag(TIF_UPROBE);
+ if (thread_info_flags & _TIF_UPROBE)
uprobe_notify_resume(regs);
- }
/* deal with pending signal delivery */
if (thread_info_flags & _TIF_SIGPENDING)
diff --git a/arch/x86/kernel/uprobes.c b/arch/x86/kernel/uprobes.c
index 9538f00..aafa555 100644
--- a/arch/x86/kernel/uprobes.c
+++ b/arch/x86/kernel/uprobes.c
@@ -651,31 +651,19 @@ void arch_uprobe_abort_xol(struct arch_uprobe *auprobe, struct pt_regs *regs)
/*
* Skip these instructions as per the currently known x86 ISA.
- * 0x66* { 0x90 | 0x0f 0x1f | 0x0f 0x19 | 0x87 0xc0 }
+ * rep=0x66*; nop=0x90
*/
static bool __skip_sstep(struct arch_uprobe *auprobe, struct pt_regs *regs)
{
int i;
for (i = 0; i < MAX_UINSN_BYTES; i++) {
- if ((auprobe->insn[i] == 0x66))
+ if (auprobe->insn[i] == 0x66)
continue;
if (auprobe->insn[i] == 0x90)
return true;
- if (i == (MAX_UINSN_BYTES - 1))
- break;
-
- if ((auprobe->insn[i] == 0x0f) && (auprobe->insn[i+1] == 0x1f))
- return true;
-
- if ((auprobe->insn[i] == 0x0f) && (auprobe->insn[i+1] == 0x19))
- return true;
-
- if ((auprobe->insn[i] == 0x87) && (auprobe->insn[i+1] == 0xc0))
- return true;
-
break;
}
return false;
diff --git a/arch/x86/oprofile/nmi_int.c b/arch/x86/oprofile/nmi_int.c
index 26b8a85..48768df 100644
--- a/arch/x86/oprofile/nmi_int.c
+++ b/arch/x86/oprofile/nmi_int.c
@@ -55,7 +55,7 @@ u64 op_x86_get_ctrl(struct op_x86_model_spec const *model,
val |= counter_config->extra;
event &= model->event_mask ? model->event_mask : 0xFF;
val |= event & 0xFF;
- val |= (event & 0x0F00) << 24;
+ val |= (u64)(event & 0x0F00) << 24;
return val;
}
diff --git a/include/linux/uprobes.h b/include/linux/uprobes.h
index e6f0331..2459457 100644
--- a/include/linux/uprobes.h
+++ b/include/linux/uprobes.h
@@ -35,16 +35,6 @@ struct inode;
# include <asm/uprobes.h>
#endif
-/* flags that denote/change uprobes behaviour */
-
-/* Have a copy of original instruction */
-#define UPROBE_COPY_INSN 0x1
-
-/* Dont run handlers when first register/ last unregister in progress*/
-#define UPROBE_RUN_HANDLER 0x2
-/* Can skip singlestep */
-#define UPROBE_SKIP_SSTEP 0x4
-
struct uprobe_consumer {
int (*handler)(struct uprobe_consumer *self, struct pt_regs *regs);
/*
@@ -59,7 +49,6 @@ struct uprobe_consumer {
#ifdef CONFIG_UPROBES
enum uprobe_task_state {
UTASK_RUNNING,
- UTASK_BP_HIT,
UTASK_SSTEP,
UTASK_SSTEP_ACK,
UTASK_SSTEP_TRAPPED,
diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c
index 98256bc..5cc4e7e 100644
--- a/kernel/events/uprobes.c
+++ b/kernel/events/uprobes.c
@@ -78,15 +78,23 @@ static struct mutex uprobes_mmap_mutex[UPROBES_HASH_SZ];
*/
static atomic_t uprobe_events = ATOMIC_INIT(0);
+/* Have a copy of original instruction */
+#define UPROBE_COPY_INSN 0
+/* Dont run handlers when first register/ last unregister in progress*/
+#define UPROBE_RUN_HANDLER 1
+/* Can skip singlestep */
+#define UPROBE_SKIP_SSTEP 2
+
struct uprobe {
struct rb_node rb_node; /* node in the rb tree */
atomic_t ref;
struct rw_semaphore consumer_rwsem;
+ struct mutex copy_mutex; /* TODO: kill me and UPROBE_COPY_INSN */
struct list_head pending_list;
struct uprobe_consumer *consumers;
struct inode *inode; /* Also hold a ref to inode */
loff_t offset;
- int flags;
+ unsigned long flags;
struct arch_uprobe arch;
};
@@ -100,17 +108,12 @@ struct uprobe {
*/
static bool valid_vma(struct vm_area_struct *vma, bool is_register)
{
- if (!vma->vm_file)
- return false;
-
- if (!is_register)
- return true;
+ vm_flags_t flags = VM_HUGETLB | VM_MAYEXEC | VM_SHARED;
- if ((vma->vm_flags & (VM_HUGETLB|VM_READ|VM_WRITE|VM_EXEC|VM_SHARED))
- == (VM_READ|VM_EXEC))
- return true;
+ if (is_register)
+ flags |= VM_WRITE;
- return false;
+ return vma->vm_file && (vma->vm_flags & flags) == VM_MAYEXEC;
}
static unsigned long offset_to_vaddr(struct vm_area_struct *vma, loff_t offset)
@@ -193,19 +196,44 @@ bool __weak is_swbp_insn(uprobe_opcode_t *insn)
return *insn == UPROBE_SWBP_INSN;
}
+static void copy_opcode(struct page *page, unsigned long vaddr, uprobe_opcode_t *opcode)
+{
+ void *kaddr = kmap_atomic(page);
+ memcpy(opcode, kaddr + (vaddr & ~PAGE_MASK), UPROBE_SWBP_INSN_SIZE);
+ kunmap_atomic(kaddr);
+}
+
+static int verify_opcode(struct page *page, unsigned long vaddr, uprobe_opcode_t *new_opcode)
+{
+ uprobe_opcode_t old_opcode;
+ bool is_swbp;
+
+ copy_opcode(page, vaddr, &old_opcode);
+ is_swbp = is_swbp_insn(&old_opcode);
+
+ if (is_swbp_insn(new_opcode)) {
+ if (is_swbp) /* register: already installed? */
+ return 0;
+ } else {
+ if (!is_swbp) /* unregister: was it changed by us? */
+ return 0;
+ }
+
+ return 1;
+}
+
/*
* NOTE:
* Expect the breakpoint instruction to be the smallest size instruction for
* the architecture. If an arch has variable length instruction and the
* breakpoint instruction is not of the smallest length instruction
- * supported by that architecture then we need to modify read_opcode /
+ * supported by that architecture then we need to modify is_swbp_at_addr and
* write_opcode accordingly. This would never be a problem for archs that
* have fixed length instructions.
*/
/*
* write_opcode - write the opcode at a given virtual address.
- * @auprobe: arch breakpointing information.
* @mm: the probed process address space.
* @vaddr: the virtual address to store the opcode.
* @opcode: opcode to be written at @vaddr.
@@ -216,8 +244,8 @@ bool __weak is_swbp_insn(uprobe_opcode_t *insn)
* For mm @mm, write the opcode at @vaddr.
* Return 0 (success) or a negative errno.
*/
-static int write_opcode(struct arch_uprobe *auprobe, struct mm_struct *mm,
- unsigned long vaddr, uprobe_opcode_t opcode)
+static int write_opcode(struct mm_struct *mm, unsigned long vaddr,
+ uprobe_opcode_t opcode)
{
struct page *old_page, *new_page;
void *vaddr_old, *vaddr_new;
@@ -226,10 +254,14 @@ static int write_opcode(struct arch_uprobe *auprobe, struct mm_struct *mm,
retry:
/* Read the page with vaddr into memory */
- ret = get_user_pages(NULL, mm, vaddr, 1, 0, 0, &old_page, &vma);
+ ret = get_user_pages(NULL, mm, vaddr, 1, 0, 1, &old_page, &vma);
if (ret <= 0)
return ret;
+ ret = verify_opcode(old_page, vaddr, &opcode);
+ if (ret <= 0)
+ goto put_old;
+
ret = -ENOMEM;
new_page = alloc_page_vma(GFP_HIGHUSER_MOVABLE, vma, vaddr);
if (!new_page)
@@ -264,63 +296,6 @@ put_old:
}
/**
- * read_opcode - read the opcode at a given virtual address.
- * @mm: the probed process address space.
- * @vaddr: the virtual address to read the opcode.
- * @opcode: location to store the read opcode.
- *
- * Called with mm->mmap_sem held (for read and with a reference to
- * mm.
- *
- * For mm @mm, read the opcode at @vaddr and store it in @opcode.
- * Return 0 (success) or a negative errno.
- */
-static int read_opcode(struct mm_struct *mm, unsigned long vaddr, uprobe_opcode_t *opcode)
-{
- struct page *page;
- void *vaddr_new;
- int ret;
-
- ret = get_user_pages(NULL, mm, vaddr, 1, 0, 1, &page, NULL);
- if (ret <= 0)
- return ret;
-
- vaddr_new = kmap_atomic(page);
- vaddr &= ~PAGE_MASK;
- memcpy(opcode, vaddr_new + vaddr, UPROBE_SWBP_INSN_SIZE);
- kunmap_atomic(vaddr_new);
-
- put_page(page);
-
- return 0;
-}
-
-static int is_swbp_at_addr(struct mm_struct *mm, unsigned long vaddr)
-{
- uprobe_opcode_t opcode;
- int result;
-
- if (current->mm == mm) {
- pagefault_disable();
- result = __copy_from_user_inatomic(&opcode, (void __user*)vaddr,
- sizeof(opcode));
- pagefault_enable();
-
- if (likely(result == 0))
- goto out;
- }
-
- result = read_opcode(mm, vaddr, &opcode);
- if (result)
- return result;
-out:
- if (is_swbp_insn(&opcode))
- return 1;
-
- return 0;
-}
-
-/**
* set_swbp - store breakpoint at a given address.
* @auprobe: arch specific probepoint information.
* @mm: the probed process address space.
@@ -331,18 +306,7 @@ out:
*/
int __weak set_swbp(struct arch_uprobe *auprobe, struct mm_struct *mm, unsigned long vaddr)
{
- int result;
- /*
- * See the comment near uprobes_hash().
- */
- result = is_swbp_at_addr(mm, vaddr);
- if (result == 1)
- return 0;
-
- if (result)
- return result;
-
- return write_opcode(auprobe, mm, vaddr, UPROBE_SWBP_INSN);
+ return write_opcode(mm, vaddr, UPROBE_SWBP_INSN);
}
/**
@@ -357,16 +321,7 @@ int __weak set_swbp(struct arch_uprobe *auprobe, struct mm_struct *mm, unsigned
int __weak
set_orig_insn(struct arch_uprobe *auprobe, struct mm_struct *mm, unsigned long vaddr)
{
- int result;
-
- result = is_swbp_at_addr(mm, vaddr);
- if (!result)
- return -EINVAL;
-
- if (result != 1)
- return result;
-
- return write_opcode(auprobe, mm, vaddr, *(uprobe_opcode_t *)auprobe->insn);
+ return write_opcode(mm, vaddr, *(uprobe_opcode_t *)auprobe->insn);
}
static int match_uprobe(struct uprobe *l, struct uprobe *r)
@@ -473,7 +428,7 @@ static struct uprobe *insert_uprobe(struct uprobe *uprobe)
spin_unlock(&uprobes_treelock);
/* For now assume that the instruction need not be single-stepped */
- uprobe->flags |= UPROBE_SKIP_SSTEP;
+ __set_bit(UPROBE_SKIP_SSTEP, &uprobe->flags);
return u;
}
@@ -495,6 +450,7 @@ static struct uprobe *alloc_uprobe(struct inode *inode, loff_t offset)
uprobe->inode = igrab(inode);
uprobe->offset = offset;
init_rwsem(&uprobe->consumer_rwsem);
+ mutex_init(&uprobe->copy_mutex);
/* add to uprobes_tree, sorted on inode:offset */
cur_uprobe = insert_uprobe(uprobe);
@@ -515,7 +471,7 @@ static void handler_chain(struct uprobe *uprobe, struct pt_regs *regs)
{
struct uprobe_consumer *uc;
- if (!(uprobe->flags & UPROBE_RUN_HANDLER))
+ if (!test_bit(UPROBE_RUN_HANDLER, &uprobe->flags))
return;
down_read(&uprobe->consumer_rwsem);
@@ -621,29 +577,43 @@ static int copy_insn(struct uprobe *uprobe, struct file *filp)
return __copy_insn(mapping, filp, uprobe->arch.insn, bytes, uprobe->offset);
}
-/*
- * How mm->uprobes_state.count gets updated
- * uprobe_mmap() increments the count if
- * - it successfully adds a breakpoint.
- * - it cannot add a breakpoint, but sees that there is a underlying
- * breakpoint (via a is_swbp_at_addr()).
- *
- * uprobe_munmap() decrements the count if
- * - it sees a underlying breakpoint, (via is_swbp_at_addr)
- * (Subsequent uprobe_unregister wouldnt find the breakpoint
- * unless a uprobe_mmap kicks in, since the old vma would be
- * dropped just after uprobe_munmap.)
- *
- * uprobe_register increments the count if:
- * - it successfully adds a breakpoint.
- *
- * uprobe_unregister decrements the count if:
- * - it sees a underlying breakpoint and removes successfully.
- * (via is_swbp_at_addr)
- * (Subsequent uprobe_munmap wouldnt find the breakpoint
- * since there is no underlying breakpoint after the
- * breakpoint removal.)
- */
+static int prepare_uprobe(struct uprobe *uprobe, struct file *file,
+ struct mm_struct *mm, unsigned long vaddr)
+{
+ int ret = 0;
+
+ if (test_bit(UPROBE_COPY_INSN, &uprobe->flags))
+ return ret;
+
+ mutex_lock(&uprobe->copy_mutex);
+ if (test_bit(UPROBE_COPY_INSN, &uprobe->flags))
+ goto out;
+
+ ret = copy_insn(uprobe, file);
+ if (ret)
+ goto out;
+
+ ret = -ENOTSUPP;
+ if (is_swbp_insn((uprobe_opcode_t *)uprobe->arch.insn))
+ goto out;
+
+ ret = arch_uprobe_analyze_insn(&uprobe->arch, mm, vaddr);
+ if (ret)
+ goto out;
+
+ /* write_opcode() assumes we don't cross page boundary */
+ BUG_ON((uprobe->offset & ~PAGE_MASK) +
+ UPROBE_SWBP_INSN_SIZE > PAGE_SIZE);
+
+ smp_wmb(); /* pairs with rmb() in find_active_uprobe() */
+ set_bit(UPROBE_COPY_INSN, &uprobe->flags);
+
+ out:
+ mutex_unlock(&uprobe->copy_mutex);
+
+ return ret;
+}
+
static int
install_breakpoint(struct uprobe *uprobe, struct mm_struct *mm,
struct vm_area_struct *vma, unsigned long vaddr)
@@ -661,24 +631,9 @@ install_breakpoint(struct uprobe *uprobe, struct mm_struct *mm,
if (!uprobe->consumers)
return 0;
- if (!(uprobe->flags & UPROBE_COPY_INSN)) {
- ret = copy_insn(uprobe, vma->vm_file);
- if (ret)
- return ret;
-
- if (is_swbp_insn((uprobe_opcode_t *)uprobe->arch.insn))
- return -ENOTSUPP;
-
- ret = arch_uprobe_analyze_insn(&uprobe->arch, mm, vaddr);
- if (ret)
- return ret;
-
- /* write_opcode() assumes we don't cross page boundary */
- BUG_ON((uprobe->offset & ~PAGE_MASK) +
- UPROBE_SWBP_INSN_SIZE > PAGE_SIZE);
-
- uprobe->flags |= UPROBE_COPY_INSN;
- }
+ ret = prepare_uprobe(uprobe, vma->vm_file, mm, vaddr);
+ if (ret)
+ return ret;
/*
* set MMF_HAS_UPROBES in advance for uprobe_pre_sstep_notifier(),
@@ -697,15 +652,15 @@ install_breakpoint(struct uprobe *uprobe, struct mm_struct *mm,
return ret;
}
-static void
+static int
remove_breakpoint(struct uprobe *uprobe, struct mm_struct *mm, unsigned long vaddr)
{
/* can happen if uprobe_register() fails */
if (!test_bit(MMF_HAS_UPROBES, &mm->flags))
- return;
+ return 0;
set_bit(MMF_RECALC_UPROBES, &mm->flags);
- set_orig_insn(&uprobe->arch, mm, vaddr);
+ return set_orig_insn(&uprobe->arch, mm, vaddr);
}
/*
@@ -820,7 +775,7 @@ static int register_for_each_vma(struct uprobe *uprobe, bool is_register)
struct mm_struct *mm = info->mm;
struct vm_area_struct *vma;
- if (err)
+ if (err && is_register)
goto free;
down_write(&mm->mmap_sem);
@@ -836,7 +791,7 @@ static int register_for_each_vma(struct uprobe *uprobe, bool is_register)
if (is_register)
err = install_breakpoint(uprobe, mm, vma, info->vaddr);
else
- remove_breakpoint(uprobe, mm, info->vaddr);
+ err |= remove_breakpoint(uprobe, mm, info->vaddr);
unlock:
up_write(&mm->mmap_sem);
@@ -893,13 +848,15 @@ int uprobe_register(struct inode *inode, loff_t offset, struct uprobe_consumer *
mutex_lock(uprobes_hash(inode));
uprobe = alloc_uprobe(inode, offset);
- if (uprobe && !consumer_add(uprobe, uc)) {
+ if (!uprobe) {
+ ret = -ENOMEM;
+ } else if (!consumer_add(uprobe, uc)) {
ret = __uprobe_register(uprobe);
if (ret) {
uprobe->consumers = NULL;
__uprobe_unregister(uprobe);
} else {
- uprobe->flags |= UPROBE_RUN_HANDLER;
+ set_bit(UPROBE_RUN_HANDLER, &uprobe->flags);
}
}
@@ -932,7 +889,7 @@ void uprobe_unregister(struct inode *inode, loff_t offset, struct uprobe_consume
if (consumer_del(uprobe, uc)) {
if (!uprobe->consumers) {
__uprobe_unregister(uprobe);
- uprobe->flags &= ~UPROBE_RUN_HANDLER;
+ clear_bit(UPROBE_RUN_HANDLER, &uprobe->flags);
}
}
@@ -1393,10 +1350,11 @@ bool uprobe_deny_signal(void)
*/
static bool can_skip_sstep(struct uprobe *uprobe, struct pt_regs *regs)
{
- if (arch_uprobe_skip_sstep(&uprobe->arch, regs))
- return true;
-
- uprobe->flags &= ~UPROBE_SKIP_SSTEP;
+ if (test_bit(UPROBE_SKIP_SSTEP, &uprobe->flags)) {
+ if (arch_uprobe_skip_sstep(&uprobe->arch, regs))
+ return true;
+ clear_bit(UPROBE_SKIP_SSTEP, &uprobe->flags);
+ }
return false;
}
@@ -1419,6 +1377,30 @@ static void mmf_recalc_uprobes(struct mm_struct *mm)
clear_bit(MMF_HAS_UPROBES, &mm->flags);
}
+static int is_swbp_at_addr(struct mm_struct *mm, unsigned long vaddr)
+{
+ struct page *page;
+ uprobe_opcode_t opcode;
+ int result;
+
+ pagefault_disable();
+ result = __copy_from_user_inatomic(&opcode, (void __user*)vaddr,
+ sizeof(opcode));
+ pagefault_enable();
+
+ if (likely(result == 0))
+ goto out;
+
+ result = get_user_pages(NULL, mm, vaddr, 1, 0, 1, &page, NULL);
+ if (result < 0)
+ return result;
+
+ copy_opcode(page, vaddr, &opcode);
+ put_page(page);
+ out:
+ return is_swbp_insn(&opcode);
+}
+
static struct uprobe *find_active_uprobe(unsigned long bp_vaddr, int *is_swbp)
{
struct mm_struct *mm = current->mm;
@@ -1489,38 +1471,41 @@ static void handle_swbp(struct pt_regs *regs)
}
return;
}
+ /*
+ * TODO: move copy_insn/etc into _register and remove this hack.
+ * After we hit the bp, _unregister + _register can install the
+ * new and not-yet-analyzed uprobe at the same address, restart.
+ */
+ smp_rmb(); /* pairs with wmb() in install_breakpoint() */
+ if (unlikely(!test_bit(UPROBE_COPY_INSN, &uprobe->flags)))
+ goto restart;
utask = current->utask;
if (!utask) {
utask = add_utask();
/* Cannot allocate; re-execute the instruction. */
if (!utask)
- goto cleanup_ret;
+ goto restart;
}
- utask->active_uprobe = uprobe;
+
handler_chain(uprobe, regs);
- if (uprobe->flags & UPROBE_SKIP_SSTEP && can_skip_sstep(uprobe, regs))
- goto cleanup_ret;
+ if (can_skip_sstep(uprobe, regs))
+ goto out;
- utask->state = UTASK_SSTEP;
if (!pre_ssout(uprobe, regs, bp_vaddr)) {
arch_uprobe_enable_step(&uprobe->arch);
+ utask->active_uprobe = uprobe;
+ utask->state = UTASK_SSTEP;
return;
}
-cleanup_ret:
- if (utask) {
- utask->active_uprobe = NULL;
- utask->state = UTASK_RUNNING;
- }
- if (!(uprobe->flags & UPROBE_SKIP_SSTEP))
-
- /*
- * cannot singlestep; cannot skip instruction;
- * re-execute the instruction.
- */
- instruction_pointer_set(regs, bp_vaddr);
-
+restart:
+ /*
+ * cannot singlestep; cannot skip instruction;
+ * re-execute the instruction.
+ */
+ instruction_pointer_set(regs, bp_vaddr);
+out:
put_uprobe(uprobe);
}
@@ -1552,13 +1537,12 @@ static void handle_singlestep(struct uprobe_task *utask, struct pt_regs *regs)
}
/*
- * On breakpoint hit, breakpoint notifier sets the TIF_UPROBE flag. (and on
- * subsequent probe hits on the thread sets the state to UTASK_BP_HIT) and
- * allows the thread to return from interrupt.
+ * On breakpoint hit, breakpoint notifier sets the TIF_UPROBE flag and
+ * allows the thread to return from interrupt. After that handle_swbp()
+ * sets utask->active_uprobe.
*
- * On singlestep exception, singlestep notifier sets the TIF_UPROBE flag and
- * also sets the state to UTASK_SSTEP_ACK and allows the thread to return from
- * interrupt.
+ * On singlestep exception, singlestep notifier sets the TIF_UPROBE flag
+ * and allows the thread to return from interrupt.
*
* While returning to userspace, thread notices the TIF_UPROBE flag and calls
* uprobe_notify_resume().
@@ -1567,11 +1551,13 @@ void uprobe_notify_resume(struct pt_regs *regs)
{
struct uprobe_task *utask;
+ clear_thread_flag(TIF_UPROBE);
+
utask = current->utask;
- if (!utask || utask->state == UTASK_BP_HIT)
- handle_swbp(regs);
- else
+ if (utask && utask->active_uprobe)
handle_singlestep(utask, regs);
+ else
+ handle_swbp(regs);
}
/*
@@ -1580,17 +1566,10 @@ void uprobe_notify_resume(struct pt_regs *regs)
*/
int uprobe_pre_sstep_notifier(struct pt_regs *regs)
{
- struct uprobe_task *utask;
-
if (!current->mm || !test_bit(MMF_HAS_UPROBES, ¤t->mm->flags))
return 0;
- utask = current->utask;
- if (utask)
- utask->state = UTASK_BP_HIT;
-
set_thread_flag(TIF_UPROBE);
-
return 1;
}
diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c
index b32ed0e..b979426 100644
--- a/kernel/trace/ring_buffer.c
+++ b/kernel/trace/ring_buffer.c
@@ -1567,6 +1567,10 @@ int ring_buffer_resize(struct ring_buffer *buffer, unsigned long size,
put_online_cpus();
} else {
+ /* Make sure this CPU has been intitialized */
+ if (!cpumask_test_cpu(cpu_id, buffer->cpumask))
+ goto out;
+
cpu_buffer = buffer->buffers[cpu_id];
if (nr_pages == cpu_buffer->nr_pages)
next reply other threads:[~2012-10-23 11:02 UTC|newest]
Thread overview: 376+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-10-23 11:02 Ingo Molnar [this message]
-- strict thread matches above, loose matches on Subject: below --
2023-01-06 11:57 [GIT PULL] perf fixes Ingo Molnar
2023-01-06 21:19 ` pr-tracker-bot
2022-10-02 10:56 Ingo Molnar
2022-10-02 16:47 ` Linus Torvalds
2022-10-03 10:55 ` Ingo Molnar
2022-10-02 17:20 ` pr-tracker-bot
2022-08-28 14:35 Ingo Molnar
2022-08-28 18:18 ` pr-tracker-bot
2022-08-06 19:10 Ingo Molnar
2022-08-07 0:50 ` pr-tracker-bot
2021-07-11 13:26 Ingo Molnar
2021-07-11 18:22 ` pr-tracker-bot
2021-06-12 12:48 Ingo Molnar
2021-06-12 19:09 ` pr-tracker-bot
2021-03-21 10:56 Ingo Molnar
2021-03-21 18:45 ` pr-tracker-bot
2020-08-15 11:21 Ingo Molnar
2020-08-16 1:55 ` pr-tracker-bot
2020-04-25 9:19 Ingo Molnar
2020-04-25 19:30 ` pr-tracker-bot
2020-03-24 9:19 Ingo Molnar
2020-03-24 17:15 ` pr-tracker-bot
2020-03-02 7:23 Ingo Molnar
2020-03-03 23:35 ` pr-tracker-bot
2020-02-15 8:53 Ingo Molnar
2020-02-15 21:25 ` pr-tracker-bot
2020-01-18 17:58 Ingo Molnar
2020-01-18 21:05 ` pr-tracker-bot
2019-12-21 16:16 Ingo Molnar
2019-12-21 18:55 ` pr-tracker-bot
2019-12-17 11:34 Ingo Molnar
2019-12-17 19:06 ` Linus Torvalds
2019-12-18 6:58 ` Ingo Molnar
2019-12-17 19:20 ` pr-tracker-bot
2019-12-01 22:15 Ingo Molnar
2019-12-02 4:40 ` pr-tracker-bot
2019-11-16 21:33 Ingo Molnar
2019-11-17 0:35 ` pr-tracker-bot
2019-11-01 17:48 Ingo Molnar
2019-11-01 18:48 ` Linus Torvalds
2019-11-01 20:30 ` Ingo Molnar
2019-11-01 21:01 ` Ingo Molnar
2019-11-01 22:15 ` Linus Torvalds
2019-11-01 19:10 ` pr-tracker-bot
2019-10-12 13:31 Ingo Molnar
2019-10-12 22:35 ` pr-tracker-bot
2019-07-14 12:01 Ingo Molnar
2019-07-14 18:45 ` pr-tracker-bot
2019-06-29 8:54 Ingo Molnar
2019-06-29 11:45 ` pr-tracker-bot
2019-06-02 17:39 Ingo Molnar
2019-06-02 18:15 ` pr-tracker-bot
2019-05-16 16:05 Ingo Molnar
2019-05-16 18:20 ` pr-tracker-bot
2019-05-05 12:47 Ingo Molnar
2019-05-05 22:10 ` pr-tracker-bot
2019-04-20 7:43 Ingo Molnar
2019-04-20 19:25 ` pr-tracker-bot
2019-04-12 13:06 Ingo Molnar
2019-04-13 4:05 ` pr-tracker-bot
2019-02-17 10:10 Ingo Molnar
2019-02-17 16:50 ` pr-tracker-bot
2019-02-10 9:01 Ingo Molnar
2019-02-10 18:30 ` pr-tracker-bot
2019-01-11 7:44 Ingo Molnar
2019-01-11 18:00 ` pr-tracker-bot
2018-11-30 6:25 Ingo Molnar
2018-11-30 21:00 ` pr-tracker-bot
2018-11-17 10:55 Ingo Molnar
2018-11-18 20:05 ` pr-tracker-bot
2018-10-20 8:10 Ingo Molnar
2018-10-20 13:28 ` Greg Kroah-Hartman
2018-10-11 9:12 Ingo Molnar
2018-10-11 12:32 ` Greg Kroah-Hartman
2018-10-11 8:59 Ingo Molnar
2018-10-05 9:42 Ingo Molnar
2018-10-05 9:55 ` Ingo Molnar
2018-10-05 23:30 ` Greg Kroah-Hartman
2018-09-15 13:11 Ingo Molnar
2018-07-30 17:53 Ingo Molnar
2018-07-13 19:59 Ingo Molnar
2018-06-30 8:44 Ingo Molnar
2018-06-04 9:04 Ingo Molnar
2018-03-31 10:40 Ingo Molnar
2018-03-25 8:53 Ingo Molnar
2018-02-06 21:29 Ingo Molnar
2017-12-06 22:17 Ingo Molnar
2017-11-26 12:40 Ingo Molnar
2017-11-05 14:40 Ingo Molnar
2017-11-09 8:13 ` Markus Trippelsdorf
2017-10-14 16:04 Ingo Molnar
2017-09-13 18:00 Ingo Molnar
2017-09-12 15:32 Ingo Molnar
2017-07-21 10:15 Ingo Molnar
2017-06-10 8:39 Ingo Molnar
2017-05-12 7:31 Ingo Molnar
2017-03-07 20:30 Ingo Molnar
2017-02-28 8:01 Ingo Molnar
2017-02-11 18:12 Ingo Molnar
2017-02-02 21:01 Ingo Molnar
2017-01-18 9:27 Ingo Molnar
2017-01-15 9:59 Ingo Molnar
2016-12-23 22:50 Ingo Molnar
2016-12-07 18:45 Ingo Molnar
2016-11-23 9:00 Ingo Molnar
2016-11-14 7:56 Ingo Molnar
2016-10-28 19:41 Ingo Molnar
2016-10-18 11:07 Ingo Molnar
2016-09-13 18:14 Ingo Molnar
2016-08-18 20:38 Ingo Molnar
2016-08-12 19:35 Ingo Molnar
2016-07-26 14:13 Ingo Molnar
2016-07-08 13:42 Ingo Molnar
2016-06-10 12:50 Ingo Molnar
2016-05-13 18:51 Ingo Molnar
2016-05-06 11:26 Ingo Molnar
2016-04-28 17:56 Ingo Molnar
2016-04-03 11:00 Ingo Molnar
2016-02-20 11:14 Ingo Molnar
2016-01-14 10:03 Ingo Molnar
2016-01-08 12:46 Ingo Molnar
2015-12-08 4:22 Ingo Molnar
2015-09-17 8:02 Ingo Molnar
2015-09-02 18:11 Ingo Molnar
2015-08-22 12:19 Ingo Molnar
2015-08-14 7:12 Ingo Molnar
2015-07-18 2:53 Ingo Molnar
2015-07-06 15:29 Ingo Molnar
2015-06-13 14:29 Ingo Molnar
2015-06-05 8:37 Ingo Molnar
2015-05-15 7:17 Ingo Molnar
2015-05-06 12:52 Ingo Molnar
2015-04-03 13:11 Ingo Molnar
2015-03-17 16:48 Ingo Molnar
2015-03-01 17:00 Ingo Molnar
2015-02-20 13:40 Ingo Molnar
2015-01-30 18:44 Ingo Molnar
2015-01-17 14:15 Ingo Molnar
2015-01-11 8:42 Ingo Molnar
2014-11-20 7:46 Ingo Molnar
2014-10-31 11:13 Ingo Molnar
2014-11-03 9:02 ` Paul Bolle
2014-11-03 10:04 ` Peter Zijlstra
2014-09-19 10:46 Ingo Molnar
2014-08-24 20:25 Ingo Molnar
2014-07-16 11:11 Ingo Molnar
2014-06-18 16:39 Ingo Molnar
2014-05-22 8:04 Ingo Molnar
2014-05-01 6:34 Ingo Molnar
2014-04-20 8:02 Ingo Molnar
2014-04-19 10:41 Ingo Molnar
2014-04-16 13:04 Ingo Molnar
2014-03-22 9:06 Ingo Molnar
2014-03-16 16:34 Ingo Molnar
2014-03-02 8:51 Ingo Molnar
2014-02-22 19:16 Ingo Molnar
2014-02-09 8:01 Ingo Molnar
2014-01-25 7:30 Ingo Molnar
2014-01-19 12:08 Ingo Molnar
2013-12-19 16:52 Ingo Molnar
2013-12-02 14:39 Ingo Molnar
2013-11-15 19:46 Ingo Molnar
2013-11-01 9:56 Ingo Molnar
2013-10-29 10:04 Ingo Molnar
2013-10-26 12:24 Ingo Molnar
2013-10-28 8:28 ` Markus Trippelsdorf
2013-10-28 9:02 ` ------------------------------ Markus Trippelsdorf
2013-10-28 9:34 ` Markus Trippelsdorf
2013-10-28 12:34 ` Arnaldo Carvalho de Melo
2013-10-28 12:42 ` Arnaldo Carvalho de Melo
2013-10-28 12:59 ` Markus Trippelsdorf
2013-10-29 9:50 ` Stephane Eranian
2013-10-29 10:06 ` Ingo Molnar
2013-10-29 12:47 ` Arnaldo Carvalho de Melo
2013-10-08 12:12 Ingo Molnar
2013-09-28 18:03 Ingo Molnar
2013-09-29 11:47 ` Markus Trippelsdorf
2013-09-29 21:33 ` Andi Kleen
2013-09-29 22:47 ` Markus Trippelsdorf
2013-09-30 6:27 ` Ingo Molnar
2013-09-30 18:54 ` Andi Kleen
2013-10-01 8:42 ` Ingo Molnar
2013-09-25 18:00 Ingo Molnar
2013-09-18 16:06 Ingo Molnar
2013-09-12 13:38 Ingo Molnar
2013-09-12 18:03 ` Linus Torvalds
2013-09-12 18:10 ` Linus Torvalds
2013-09-12 18:43 ` Arnaldo Carvalho de Melo
2013-09-12 19:12 ` Arnaldo Carvalho de Melo
2013-09-12 19:13 ` Linus Torvalds
2013-09-12 19:55 ` Ingo Molnar
2013-09-12 19:58 ` David Ahern
2013-09-12 20:02 ` Arnaldo Carvalho de Melo
2013-09-12 20:31 ` Ingo Molnar
2013-09-12 20:43 ` Ingo Molnar
2013-09-12 20:18 ` Ingo Molnar
2013-09-12 20:38 ` Arnaldo Carvalho de Melo
2013-09-12 20:46 ` Ingo Molnar
2013-09-12 21:09 ` David Ahern
2013-09-12 21:18 ` Ingo Molnar
2013-09-12 22:10 ` David Ahern
2013-09-13 5:09 ` Ingo Molnar
2013-09-13 9:32 ` Jean Pihet
2013-09-13 9:45 ` Ingo Molnar
2013-09-13 17:15 ` Jean Pihet
2013-09-12 18:51 ` Linus Torvalds
2013-09-12 20:33 ` Ingo Molnar
2013-09-12 20:38 ` Linus Torvalds
2013-09-12 20:49 ` Ingo Molnar
2013-09-12 20:52 ` Linus Torvalds
2013-09-12 21:01 ` Ingo Molnar
2013-09-12 20:10 ` Ingo Molnar
2013-08-13 16:51 Ingo Molnar
2013-07-10 8:52 Ingo Molnar
2013-06-26 8:52 Ingo Molnar
2013-06-20 8:58 Ingo Molnar
2013-05-05 10:10 Ingo Molnar
2013-04-21 8:16 Ingo Molnar
2013-04-14 15:20 Ingo Molnar
2013-03-21 9:56 Ingo Molnar
2013-03-11 14:28 Ingo Molnar
2013-02-26 7:02 Ingo Molnar
2013-03-14 20:32 ` Linus Torvalds
2013-03-14 21:06 ` Linus Torvalds
2013-03-14 22:09 ` Stephane Eranian
2013-03-14 22:17 ` Linus Torvalds
2013-03-14 22:19 ` Stephane Eranian
2013-03-14 22:42 ` Stephane Eranian
2013-03-14 22:53 ` Stephane Eranian
2013-03-14 23:11 ` Stephane Eranian
2013-03-15 0:24 ` Stephane Eranian
2013-03-15 1:06 ` Linus Torvalds
2013-03-15 8:01 ` Stephane Eranian
2013-03-15 10:50 ` Stephane Eranian
2013-02-04 18:20 Ingo Molnar
2012-12-01 11:11 Ingo Molnar
2012-10-26 14:44 Ingo Molnar
2012-10-20 0:56 Ingo Molnar
2012-09-21 19:08 Ingo Molnar
2012-09-13 14:39 Ingo Molnar
2012-08-23 10:59 Ingo Molnar
2012-08-20 9:08 Ingo Molnar
2012-08-21 7:59 ` Ingo Molnar
2012-08-05 17:43 Ingo Molnar
2012-08-03 16:40 Ingo Molnar
2012-07-14 7:51 Ingo Molnar
2012-06-22 13:36 Ingo Molnar
2012-06-22 18:07 ` Linus Torvalds
2012-06-22 18:38 ` Hagen Paul Pfeifer
2012-06-22 18:52 ` Linus Torvalds
2012-06-22 19:06 ` Hagen Paul Pfeifer
2012-06-22 19:54 ` Steven Rostedt
[not found] ` <86448d73-2e19-416f-8104-ce72aa5d76eb@email.android.com>
2012-06-22 23:18 ` Steven Rostedt
2012-06-23 0:51 ` Arjan van de Ven
2012-06-23 1:57 ` Steven Rostedt
2012-06-23 18:25 ` H. Peter Anvin
2012-06-22 18:50 ` Steven Rostedt
2012-06-15 18:48 Ingo Molnar
2012-06-08 9:20 Ingo Molnar
2012-05-30 15:39 Ingo Molnar
2012-05-17 8:19 Ingo Molnar
2012-04-27 6:32 Ingo Molnar
2012-04-16 17:48 Ingo Molnar
2012-04-14 10:54 Ingo Molnar
2012-04-03 22:40 Ingo Molnar
2012-03-13 16:56 Ingo Molnar
2012-03-05 9:27 Ingo Molnar
2012-03-02 10:47 Ingo Molnar
2012-02-10 12:45 Ingo Molnar
2012-02-02 10:00 Ingo Molnar
2012-01-26 18:11 Ingo Molnar
2011-12-29 21:02 Ingo Molnar
2011-12-09 6:16 Ingo Molnar
2011-12-05 19:13 Ingo Molnar
2011-11-07 18:49 Ingo Molnar
2011-11-07 19:00 ` Linus Torvalds
2011-11-07 19:50 ` Ingo Molnar
2011-08-22 17:00 Ingo Molnar
2011-08-11 8:17 Ingo Molnar
2011-07-07 18:11 Ingo Molnar
2011-06-19 8:44 Ingo Molnar
2011-06-13 9:53 Ingo Molnar
2011-06-08 13:46 Ingo Molnar
2011-05-28 16:34 Ingo Molnar
2011-05-24 2:41 Ingo Molnar
2011-05-23 13:41 Ingo Molnar
2011-05-23 22:10 ` Eric Dumazet
2011-05-23 22:19 ` Frederic Weisbecker
2011-05-23 22:22 ` Eric Dumazet
2011-05-20 17:18 Ingo Molnar
2011-05-17 22:07 Ingo Molnar
2011-05-07 18:20 Ingo Molnar
2011-04-29 18:17 Ingo Molnar
2011-04-22 13:42 Ingo Molnar
2011-04-19 15:56 Ingo Molnar
2011-04-16 10:03 Ingo Molnar
2011-04-07 17:48 Ingo Molnar
2011-04-02 10:25 Ingo Molnar
2011-03-25 13:11 Ingo Molnar
2011-03-10 7:53 Ingo Molnar
2011-02-28 17:34 Ingo Molnar
2011-02-22 16:03 Ingo Molnar
2011-02-15 16:58 Ingo Molnar
2011-02-06 11:27 Ingo Molnar
2011-02-03 15:47 Ingo Molnar
2011-01-24 13:34 Ingo Molnar
2011-01-24 19:48 ` Linus Torvalds
2011-01-24 20:07 ` Ingo Molnar
2011-01-24 20:11 ` Ingo Molnar
2011-01-24 20:17 ` Ingo Molnar
2011-01-24 20:17 ` Linus Torvalds
2011-01-24 20:27 ` Linus Torvalds
2011-01-24 20:38 ` Arnaldo Carvalho de Melo
2011-01-24 21:13 ` Linus Torvalds
2011-01-24 21:25 ` Ingo Molnar
2011-01-24 22:00 ` Arnaldo Carvalho de Melo
2011-01-25 0:16 ` Ingo Molnar
2011-01-24 20:37 ` Davidlohr Bueso
2011-01-24 20:14 ` Arnaldo Carvalho de Melo
2011-01-18 18:59 Ingo Molnar
2011-01-18 9:42 Ingo Molnar
2011-01-15 15:24 Ingo Molnar
2011-01-11 11:32 Ingo Molnar
2011-01-03 19:04 Ingo Molnar
2010-12-23 12:56 Ingo Molnar
2010-12-19 15:34 Ingo Molnar
2010-12-08 7:55 Ingo Molnar
2010-11-28 17:36 Ingo Molnar
2010-11-26 13:20 Ingo Molnar
2010-11-11 10:38 Ingo Molnar
2010-10-30 18:21 Ingo Molnar
2010-10-13 15:21 Ingo Molnar
2010-10-05 14:49 Ingo Molnar
2010-09-26 8:38 Ingo Molnar
2010-09-21 19:39 Ingo Molnar
2010-09-10 14:26 Ingo Molnar
2010-08-25 17:44 Ingo Molnar
2010-08-24 19:06 Ingo Molnar
2010-08-19 14:55 Ingo Molnar
2010-08-18 8:14 Ingo Molnar
2010-07-23 19:41 Ingo Molnar
2010-07-16 17:30 Ingo Molnar
2010-07-08 4:36 Frederic Weisbecker
2010-07-08 4:40 ` Frederic Weisbecker
2010-07-08 6:36 ` Ingo Molnar
2010-07-04 20:24 Ingo Molnar
2010-06-10 10:25 Ingo Molnar
2010-06-02 12:28 Ingo Molnar
2010-05-31 23:02 Frederic Weisbecker
2010-06-01 6:59 ` Ingo Molnar
2010-05-30 19:27 Ingo Molnar
2010-05-20 9:44 Frederic Weisbecker
2010-05-20 12:40 ` Ingo Molnar
2010-05-11 19:18 Ingo Molnar
2010-05-12 0:39 ` Linus Torvalds
2010-04-06 17:49 Ingo Molnar
2010-04-04 10:15 Ingo Molnar
2010-04-03 10:47 Frederic Weisbecker
2010-03-28 5:11 Frederic Weisbecker
2010-03-29 3:33 ` Ingo Molnar
2010-03-26 15:16 Ingo Molnar
2010-03-16 16:06 Ingo Molnar
2010-03-11 19:12 Ingo Molnar
2010-02-22 16:50 Ingo Molnar
2010-02-22 17:01 ` Linus Torvalds
2010-02-22 17:15 ` Frederic Weisbecker
2010-02-14 9:06 Ingo Molnar
2010-01-31 17:32 Ingo Molnar
2010-01-21 15:38 Ingo Molnar
2009-12-31 12:00 Ingo Molnar
2009-12-18 18:59 Ingo Molnar
2009-09-22 7:51 Ingo Molnar
2009-09-22 14:49 ` Linus Torvalds
2009-09-22 14:59 ` Ingo Molnar
2009-09-22 15:13 ` Linus Torvalds
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20121023110207.GA28324@gmail.com \
--to=mingo@kernel.org \
--cc=a.p.zijlstra@chello.nl \
--cc=acme@infradead.org \
--cc=akpm@linux-foundation.org \
--cc=linux-kernel@vger.kernel.org \
--cc=oleg@redhat.com \
--cc=tglx@linutronix.de \
--cc=torvalds@linux-foundation.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.