* Re: [PATCH 1/7] powerpc/spufs: simplify spufs core dumping
From: Christoph Hellwig @ 2020-04-21 19:01 UTC (permalink / raw)
To: Al Viro
Cc: Arnd Bergmann, linux-kernel, Eric W . Biederman, linux-fsdevel,
Andrew Morton, linuxppc-dev, Christoph Hellwig, Jeremy Kerr
In-Reply-To: <20200421184941.GD23230@ZenIV.linux.org.uk>
On Tue, Apr 21, 2020 at 07:49:41PM +0100, Al Viro wrote:
> > spin_lock(&ctx->csa.register_lock);
> > - ret = __spufs_proxydma_info_read(ctx, buf, len, pos);
> > + __spufs_proxydma_info_read(ctx, &info);
> > + ret = simple_read_from_buffer(buf, len, pos, &info, sizeof(info));
>
> IDGI... What's that access_ok() for? If you are using simple_read_from_buffer(),
> the damn thing goes through copy_to_user(). Why bother with separate access_ok()
> here?
I have no idea at all, this just refactors the code.
^ permalink raw reply
* Re: [PATCH 1/7] powerpc/spufs: simplify spufs core dumping
From: Al Viro @ 2020-04-21 18:49 UTC (permalink / raw)
To: Christoph Hellwig
Cc: Arnd Bergmann, linux-kernel, Jeremy Kerr, linux-fsdevel,
Andrew Morton, linuxppc-dev, Eric W . Biederman
In-Reply-To: <20200421154204.252921-2-hch@lst.de>
On Tue, Apr 21, 2020 at 05:41:58PM +0200, Christoph Hellwig wrote:
> static ssize_t spufs_proxydma_info_read(struct file *file, char __user *buf,
> size_t len, loff_t *pos)
> {
> struct spu_context *ctx = file->private_data;
> + struct spu_proxydma_info info;
> int ret;
>
> + if (len < sizeof(info))
> + return -EINVAL;
> + if (!access_ok(buf, len))
> + return -EFAULT;
> +
> ret = spu_acquire_saved(ctx);
> if (ret)
> return ret;
> spin_lock(&ctx->csa.register_lock);
> - ret = __spufs_proxydma_info_read(ctx, buf, len, pos);
> + __spufs_proxydma_info_read(ctx, &info);
> + ret = simple_read_from_buffer(buf, len, pos, &info, sizeof(info));
IDGI... What's that access_ok() for? If you are using simple_read_from_buffer(),
the damn thing goes through copy_to_user(). Why bother with separate access_ok()
here?
^ permalink raw reply
* Re: [PATCH v2 5/5] uaccess: Rename user_access_begin/end() to user_full_access_begin/end()
From: Linus Torvalds @ 2020-04-21 18:34 UTC (permalink / raw)
To: Al Viro
Cc: linux-arch, Kees Cook, Dave Airlie, intel-gfx, Peter Anvin,
Linux Kernel Mailing List, Russell King, Linux-MM, Paul Mackerras,
Daniel Vetter, Andrew Morton, linuxppc-dev
In-Reply-To: <20200421024919.GA23230@ZenIV.linux.org.uk>
On Mon, Apr 20, 2020 at 7:49 PM Al Viro <viro@zeniv.linux.org.uk> wrote:
>
> The only source I'd been able to find speaks of >= 60 cycles
> (and possibly much more) for non-pipelined coprocessor instructions;
> the list of such does contain loads and stores to a bunch of registers.
> However, the register in question (p15/c3) has only store mentioned there,
> so loads might be cheap; no obvious reasons for those to be slow.
> That's a question to arm folks, I'm afraid... rmk?
_If_ it turns out to be expensive, is there any reason we couldn't
just cache the value in general?
That's what x86 tends to do with expensive system registers. One
example would be "msr_misc_features_shadow".
But maybe that's something to worry about when/if it turns out to
actually be a problem?
Linus
^ permalink raw reply
* Re: [PATCH v9 0/7] ASoC: Add new module driver for new ASRC
From: Mark Brown @ 2020-04-21 18:22 UTC (permalink / raw)
To: Xiubo.Lee, devicetree, nicoleotsuka, perex, lgirdwood, alsa-devel,
Shengjiu Wang, timur, robh+dt, mark.rutland, festevam, tiwai
Cc: linuxppc-dev, linux-kernel
In-Reply-To: <cover.1587038908.git.shengjiu.wang@nxp.com>
On Thu, 16 Apr 2020 20:25:30 +0800, Shengjiu Wang wrote:
> Add new module driver for new ASRC in i.MX8MN, several commits
> are added for new property fsl,asrc-format
>
> Shengjiu Wang (7):
> ASoC: fsl_asrc: rename asrc_priv to asrc
> ASoC: dt-bindings: fsl_asrc: Add new property fsl,asrc-format
> ASoC: fsl-asoc-card: Support new property fsl,asrc-format
> ASoC: fsl_asrc: Support new property fsl,asrc-format
> ASoC: fsl_asrc: Move common definition to fsl_asrc_common
> ASoC: dt-bindings: fsl_easrc: Add document for EASRC
> ASoC: fsl_easrc: Add EASRC ASoC CPU DAI drivers
>
> [...]
Applied to
https://git.kernel.org/pub/scm/linux/kernel/git/broonie/sound.git for-5.8
Thanks!
[1/7] ASoC: fsl_asrc: rename asrc_priv to asrc
commit: 7470704d8b425c4c7045884690f92cf015563aac
[2/7] ASoC: dt-bindings: fsl_asrc: Add new property fsl, asrc-format
commit: b84b4c9a688d803b0e7cf91fec9a5d8b3ba47768
[3/7] ASoC: fsl-asoc-card: Support new property fsl, asrc-format
commit: 859e364302c510cfdd9abda13a3c4c1d1bc68c57
[4/7] ASoC: fsl_asrc: Support new property fsl,asrc-format
commit: 4520af41fd21863d026d53c7e1eb987509cb3c24
[5/7] ASoC: fsl_asrc: Move common definition to fsl_asrc_common
commit: be7bd03f0201b5a513ced98c08444a140eab92ea
[6/7] ASoC: dt-bindings: fsl_easrc: Add document for EASRC
commit: a960de4da241d409a73e318ab19e6b5fdcd95a83
[7/7] ASoC: fsl_easrc: Add EASRC ASoC CPU DAI drivers
commit: 955ac624058f91172b3b8820280556e699e1e0ff
All being well this means that it will be integrated into the linux-next
tree (usually sometime in the next 24 hours) and sent to Linus during
the next merge window (or sooner if it is a bug fix), however if
problems are discovered then the patch may be dropped or reverted.
You may get further e-mails resulting from automated or manual testing
and review of the tree, please engage with people reporting problems and
send followup patches addressing any issues that are reported if needed.
If any updates are required or you are submitting further changes they
should be sent as incremental updates against current git, existing
patches will not be replaced.
Please add any relevant lists and maintainers to the CCs when replying
to this mail.
Thanks,
Mark
^ permalink raw reply
* Re: [PATCH v8 0/7] ASoC: Add new module driver for new ASRC
From: Mark Brown @ 2020-04-21 18:22 UTC (permalink / raw)
To: devicetree, Xiubo.Lee, festevam, perex, nicoleotsuka, alsa-devel,
Shengjiu Wang, timur, robh+dt, mark.rutland, lgirdwood, tiwai
Cc: linuxppc-dev, linux-kernel
In-Reply-To: <cover.1586845137.git.shengjiu.wang@nxp.com>
On Tue, 14 Apr 2020 14:56:00 +0800, Shengjiu Wang wrote:
> Add new module driver for new ASRC in i.MX8MN, several commits
> are added for new property fsl,asrc-format
>
> Shengjiu Wang (7):
> ASoC: fsl_asrc: rename asrc_priv to asrc
> ASoC: dt-bindings: fsl_asrc: Add new property fsl,asrc-format
> ASoC: fsl-asoc-card: Support new property fsl,asrc-format
> ASoC: fsl_asrc: Support new property fsl,asrc-format
> ASoC: fsl_asrc: Move common definition to fsl_asrc_common
> ASoC: dt-bindings: fsl_easrc: Add document for EASRC
> ASoC: fsl_easrc: Add EASRC ASoC CPU DAI drivers
>
> [...]
Applied to
https://git.kernel.org/pub/scm/linux/kernel/git/broonie/sound.git for-5.8
Thanks!
[1/7] ASoC: fsl_asrc: rename asrc_priv to asrc
commit: 7470704d8b425c4c7045884690f92cf015563aac
[2/7] ASoC: dt-bindings: fsl_asrc: Add new property fsl, asrc-format
commit: b84b4c9a688d803b0e7cf91fec9a5d8b3ba47768
[3/7] ASoC: fsl-asoc-card: Support new property fsl, asrc-format
commit: 859e364302c510cfdd9abda13a3c4c1d1bc68c57
[4/7] ASoC: fsl_asrc: Support new property fsl,asrc-format
commit: 4520af41fd21863d026d53c7e1eb987509cb3c24
[5/7] ASoC: fsl_asrc: Move common definition to fsl_asrc_common
commit: be7bd03f0201b5a513ced98c08444a140eab92ea
[6/7] ASoC: dt-bindings: fsl_easrc: Add document for EASRC
commit: a960de4da241d409a73e318ab19e6b5fdcd95a83
[7/7] ASoC: fsl_easrc: Add EASRC ASoC CPU DAI drivers
commit: 955ac624058f91172b3b8820280556e699e1e0ff
All being well this means that it will be integrated into the linux-next
tree (usually sometime in the next 24 hours) and sent to Linus during
the next merge window (or sooner if it is a bug fix), however if
problems are discovered then the patch may be dropped or reverted.
You may get further e-mails resulting from automated or manual testing
and review of the tree, please engage with people reporting problems and
send followup patches addressing any issues that are reported if needed.
If any updates are required or you are submitting further changes they
should be sent as incremental updates against current git, existing
patches will not be replaced.
Please add any relevant lists and maintainers to the CCs when replying
to this mail.
Thanks,
Mark
^ permalink raw reply
* Re: [PATCH 1/2] powerpc: Add base support for ISA v3.1
From: Segher Boessenkool @ 2020-04-21 17:50 UTC (permalink / raw)
To: Oliver O'Halloran
Cc: Alistair Popple, Michael Neuling, linuxppc-dev, Nicholas Piggin
In-Reply-To: <CAOSf1CGP02VW9adNyBcHF4_BZiv-jKohH4qihj7BmEgAif0VLA@mail.gmail.com>
Hi,
On Tue, Apr 21, 2020 at 11:58:31AM +1000, Oliver O'Halloran wrote:
> On Tue, Apr 21, 2020 at 11:53 AM Alistair Popple <alistair@popple.id.au> wrote:
> >
> > On Tuesday, 21 April 2020 11:30:52 AM AEST Alistair Popple wrote:
> > > On Saturday, 4 April 2020 2:32:08 AM AEST Segher Boessenkool wrote:
> > > > Hi!
> > > >
> > > > On Fri, Apr 03, 2020 at 03:10:54PM +1100, Alistair Popple wrote:
> > > > > +#define PCR_ARCH_300 0x10 /* Architecture 3.00 */
> > > >
> > > > It's called 3.0, not 3.00?
> > >
> > > Thanks. I'll fix that up.
> >
> > Actually we have already defined it upstream as CPU_FTR_ARCH_300 in arch/
> > powerpc/include/asm/cputable.h and PVR_ARCH_300 in arch/powerpc/include/asm/
> > reg.h so for consistency we should make it the same here. So either we leave
> > this patch as is or we change it to PCR_ARCH_30 along with the existing
> > upstream #defines. Thoughts?
>
> I used 300 for consistency with the existing three digit definitions
> when I added the CPU_FTR macro. It doesn't really matter since these
> are all internal definitions, but I SAY THE BIKESHED SHOULD BE THREE
> DIGITS LONG.
You can do in your own symbols whatever you want, but the comment is
refering to an existing real-world version of the ISA, namely, 3.0 :-)
(It's important to get names right, and especially in the canonical
places, like this one. IMO of course).
Segher
^ permalink raw reply
* Re: [PATCH] KVM: PPC: Book3S HV: read ibm,secure-memory nodes
From: Laurent Dufour @ 2020-04-21 17:39 UTC (permalink / raw)
To: Oliver O'Halloran, Michael Ellerman
Cc: Alexey Kardashevskiy, Paul Mackerras, linuxppc-dev,
Linux Kernel Mailing List, kvm-ppc
In-Reply-To: <CAOSf1CF2YEG1U_1XP_Vvk3Bn1RCiNa1DAKEbemWu00JimoPsUQ@mail.gmail.com>
Le 21/04/2020 à 15:43, Oliver O'Halloran a écrit :
> On Tue, Apr 21, 2020 at 11:37 PM Michael Ellerman <mpe@ellerman.id.au> wrote:
>>
>> Hi Laurent,
>>
>> Laurent Dufour <ldufour@linux.ibm.com> writes:
>>> The newly introduced ibm,secure-memory nodes supersede the
>>> ibm,uv-firmware's property secure-memory-ranges.
>>
>> Is either documented in a device tree binding document anywhere?
>>
>> cheers
>>
>>> Firmware will no more expose the secure-memory-ranges property so first
>>> read the new one and if not found rollback to the older one.
>
> There's some in Ryan's UV support series for skiboot:
>
> https://patchwork.ozlabs.org/project/skiboot/patch/20200227204023.22125-2-grimm@linux.ibm.com/
>
> ...which is also marked RFC. Cool.
Thanks Oliver for this pointer.
Yes this is an RFC but this documentation details the secure memory nodes
created by skiboot and parsed by this patch.
Michael, is that enough for you?
Laurent.
^ permalink raw reply
* [PATCH 3/3] powerpc/module_64: Use special stub for _mcount() with -mprofile-kernel
From: Naveen N. Rao @ 2020-04-21 17:35 UTC (permalink / raw)
To: linuxppc-dev; +Cc: Qian Cai, Steven Rostedt
In-Reply-To: <cover.1587488954.git.naveen.n.rao@linux.vnet.ibm.com>
Since commit c55d7b5e64265f ("powerpc: Remove STRICT_KERNEL_RWX
incompatibility with RELOCATABLE"), powerpc kernels with
-mprofile-kernel can crash in certain scenarios with a trace like below:
BUG: Unable to handle kernel instruction fetch (NULL pointer?)
Faulting instruction address: 0x00000000
Oops: Kernel access of bad area, sig: 11 [#1]
LE PAGE_SIZE=64K MMU=Radix SMP NR_CPUS=256 DEBUG_PAGEALLOC NUMA PowerNV
<snip>
NIP [0000000000000000] 0x0
LR [c0080000102c0048] ext4_iomap_end+0x8/0x30 [ext4]
Call Trace:
iomap_apply+0x20c/0x920 (unreliable)
iomap_bmap+0xfc/0x160
ext4_bmap+0xa4/0x180 [ext4]
bmap+0x4c/0x80
jbd2_journal_init_inode+0x44/0x1a0 [jbd2]
ext4_load_journal+0x440/0x860 [ext4]
ext4_fill_super+0x342c/0x3ab0 [ext4]
mount_bdev+0x25c/0x290
ext4_mount+0x28/0x50 [ext4]
legacy_get_tree+0x4c/0xb0
vfs_get_tree+0x4c/0x130
do_mount+0xa18/0xc50
sys_mount+0x158/0x180
system_call+0x5c/0x68
The NIP points to NULL, or a random location (data even), while the LR
always points to the LEP of a function (with an offset of 8), indicating
that something went wrong with ftrace. However, ftrace is not
necessarily active when such crashes occur.
The kernel OOPS sometimes follows a warning from ftrace indicating that
some module functions could not be patched with a nop. Other times, if a
module is loaded early during boot, instruction patching can fail due to
a separate bug, but the error is not reported due to missing error
reporting.
In all the above cases when instruction patching fails, ftrace will be
disabled but certain kernel module functions will be left with default
calls to _mcount(). This is not a problem with ELFv1. However, with
-mprofile-kernel, the default stub is problematic since it depends on a
valid module TOC in r2. If the kernel (or a different module) calls into
a function that does not use the TOC, the function won't have a prologue
to setup the module TOC. When that function calls into _mcount(), we
will end up in the relocation stub that will use the previous TOC, and
end up trying to jump into a random location. From the above trace:
iomap_apply+0x20c/0x920 [kernel TOC]
|
V
ext4_iomap_end+0x8/0x30 [no GEP == kernel TOC]
|
V
_mcount() stub
[uses kernel TOC -> random entry]
To address this, let's change over to using the special stub that is
used for ftrace_[regs_]caller() for _mcount(). This ensures that we are
not dependent on a valid module TOC in r2 for default _mcount()
handling.
Reported-by: Qian Cai <cai@lca.pw>
Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
---
arch/powerpc/kernel/module_64.c | 222 +++++++++++++++-----------------
1 file changed, 104 insertions(+), 118 deletions(-)
diff --git a/arch/powerpc/kernel/module_64.c b/arch/powerpc/kernel/module_64.c
index 7f4cc5346387..cc7e990e8376 100644
--- a/arch/powerpc/kernel/module_64.c
+++ b/arch/powerpc/kernel/module_64.c
@@ -348,6 +348,92 @@ int module_frob_arch_sections(Elf64_Ehdr *hdr,
return 0;
}
+#ifdef CONFIG_MPROFILE_KERNEL
+
+#define PACATOC offsetof(struct paca_struct, kernel_toc)
+
+/*
+ * ld r12,PACATOC(r13)
+ * addis r12,r12,<high>
+ * addi r12,r12,<low>
+ * mtctr r12
+ * bctr
+ */
+static u32 stub_insns[] = {
+ PPC_INST_LD | __PPC_RT(R12) | __PPC_RA(R13) | PACATOC,
+ PPC_INST_ADDIS | __PPC_RT(R12) | __PPC_RA(R12),
+ PPC_INST_ADDI | __PPC_RT(R12) | __PPC_RA(R12),
+ PPC_INST_MTCTR | __PPC_RS(R12),
+ PPC_INST_BCTR,
+};
+
+/*
+ * For mprofile-kernel we use a special stub for ftrace_caller() because we
+ * can't rely on r2 containing this module's TOC when we enter the stub.
+ *
+ * That can happen if the function calling us didn't need to use the toc. In
+ * that case it won't have setup r2, and the r2 value will be either the
+ * kernel's toc, or possibly another modules toc.
+ *
+ * To deal with that this stub uses the kernel toc, which is always accessible
+ * via the paca (in r13). The target (ftrace_caller()) is responsible for
+ * saving and restoring the toc before returning.
+ */
+static inline int create_ftrace_stub(struct ppc64_stub_entry *entry,
+ unsigned long addr,
+ struct module *me)
+{
+ long reladdr;
+
+ memcpy(entry->jump, stub_insns, sizeof(stub_insns));
+
+ /* Stub uses address relative to kernel toc (from the paca) */
+ reladdr = addr - kernel_toc_addr();
+ if (reladdr > 0x7FFFFFFF || reladdr < -(0x80000000L)) {
+ pr_err("%s: Address of %ps out of range of kernel_toc.\n",
+ me->name, (void *)addr);
+ return 0;
+ }
+
+ entry->jump[1] |= PPC_HA(reladdr);
+ entry->jump[2] |= PPC_LO(reladdr);
+
+ /* Eventhough we don't use funcdata in the stub, it's needed elsewhere. */
+ entry->funcdata = func_desc(addr);
+ entry->magic = STUB_MAGIC;
+
+ return 1;
+}
+
+static bool is_mprofile_ftrace_call(const char *name)
+{
+ if (!strcmp("_mcount", name))
+ return true;
+#ifdef CONFIG_DYNAMIC_FTRACE
+ if (!strcmp("ftrace_caller", name))
+ return true;
+#ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
+ if (!strcmp("ftrace_regs_caller", name))
+ return true;
+#endif
+#endif
+
+ return false;
+}
+#else
+static inline int create_ftrace_stub(struct ppc64_stub_entry *entry,
+ unsigned long addr,
+ struct module *me)
+{
+ return 0;
+}
+
+static bool is_mprofile_ftrace_call(const char *name)
+{
+ return false;
+}
+#endif
+
/*
* r2 is the TOC pointer: it actually points 0x8000 into the TOC (this gives the
* value maximum span in an instruction which uses a signed offset). Round down
@@ -363,10 +449,14 @@ static inline unsigned long my_r2(const Elf64_Shdr *sechdrs, struct module *me)
static inline int create_stub(const Elf64_Shdr *sechdrs,
struct ppc64_stub_entry *entry,
unsigned long addr,
- struct module *me)
+ struct module *me,
+ const char *name)
{
long reladdr;
+ if (is_mprofile_ftrace_call(name))
+ return create_ftrace_stub(entry, addr, me);
+
memcpy(entry->jump, ppc64_stub_insns, sizeof(ppc64_stub_insns));
/* Stub uses address relative to r2. */
@@ -390,7 +480,8 @@ static inline int create_stub(const Elf64_Shdr *sechdrs,
stub to set up the TOC ptr (r2) for the function. */
static unsigned long stub_for_addr(const Elf64_Shdr *sechdrs,
unsigned long addr,
- struct module *me)
+ struct module *me,
+ const char *name)
{
struct ppc64_stub_entry *stubs;
unsigned int i, num_stubs;
@@ -407,45 +498,12 @@ static unsigned long stub_for_addr(const Elf64_Shdr *sechdrs,
return (unsigned long)&stubs[i];
}
- if (!create_stub(sechdrs, &stubs[i], addr, me))
+ if (!create_stub(sechdrs, &stubs[i], addr, me, name))
return 0;
return (unsigned long)&stubs[i];
}
-#ifdef CONFIG_MPROFILE_KERNEL
-static bool is_mprofile_ftrace_call(const char *name)
-{
- if (!strcmp("_mcount", name))
- return true;
-
- return false;
-}
-
-/*
- * In case of _mcount calls, do not save the current callee's TOC (in r2) into
- * the original caller's stack frame. If we did we would clobber the saved TOC
- * value of the original caller.
- */
-static void squash_toc_save_inst(const char *name, unsigned long addr)
-{
- struct ppc64_stub_entry *stub = (struct ppc64_stub_entry *)addr;
-
- /* Only for calls to _mcount */
- if (strcmp("_mcount", name) != 0)
- return;
-
- stub->jump[2] = PPC_INST_NOP;
-}
-#else
-static void squash_toc_save_inst(const char *name, unsigned long addr) { }
-
-static bool is_mprofile_ftrace_call(const char *name)
-{
- return false;
-}
-#endif
-
/* We expect a noop next: if it is, replace it with instruction to
restore r2. */
static int restore_r2(const char *name, u32 *instruction, struct module *me)
@@ -590,14 +648,13 @@ int apply_relocate_add(Elf64_Shdr *sechdrs,
if (sym->st_shndx == SHN_UNDEF ||
sym->st_shndx == SHN_LIVEPATCH) {
/* External: go via stub */
- value = stub_for_addr(sechdrs, value, me);
+ value = stub_for_addr(sechdrs, value, me,
+ strtab + sym->st_name);
if (!value)
return -ENOENT;
if (!restore_r2(strtab + sym->st_name,
(u32 *)location + 1, me))
return -ENOEXEC;
-
- squash_toc_save_inst(strtab + sym->st_name, value);
} else
value += local_entry_offset(sym);
@@ -733,88 +790,17 @@ int module_trampoline_target(struct module *mod, unsigned long addr,
return 0;
}
-#ifdef CONFIG_MPROFILE_KERNEL
-
-#define PACATOC offsetof(struct paca_struct, kernel_toc)
-
-/*
- * For mprofile-kernel we use a special stub for ftrace_caller() because we
- * can't rely on r2 containing this module's TOC when we enter the stub.
- *
- * That can happen if the function calling us didn't need to use the toc. In
- * that case it won't have setup r2, and the r2 value will be either the
- * kernel's toc, or possibly another modules toc.
- *
- * To deal with that this stub uses the kernel toc, which is always accessible
- * via the paca (in r13). The target (ftrace_caller()) is responsible for
- * saving and restoring the toc before returning.
- */
-static unsigned long create_ftrace_stub(const Elf64_Shdr *sechdrs,
- struct module *me, unsigned long addr)
-{
- struct ppc64_stub_entry *entry;
- unsigned int i, num_stubs;
- /*
- * ld r12,PACATOC(r13)
- * addis r12,r12,<high>
- * addi r12,r12,<low>
- * mtctr r12
- * bctr
- */
- static u32 stub_insns[] = {
- PPC_INST_LD | __PPC_RT(R12) | __PPC_RA(R13) | PACATOC,
- PPC_INST_ADDIS | __PPC_RT(R12) | __PPC_RA(R12),
- PPC_INST_ADDI | __PPC_RT(R12) | __PPC_RA(R12),
- PPC_INST_MTCTR | __PPC_RS(R12),
- PPC_INST_BCTR,
- };
- long reladdr;
-
- num_stubs = sechdrs[me->arch.stubs_section].sh_size / sizeof(*entry);
-
- /* Find the next available stub entry */
- entry = (void *)sechdrs[me->arch.stubs_section].sh_addr;
- for (i = 0; i < num_stubs && stub_func_addr(entry->funcdata); i++, entry++);
-
- if (i >= num_stubs) {
- pr_err("%s: Unable to find a free slot for ftrace stub.\n", me->name);
- return 0;
- }
-
- memcpy(entry->jump, stub_insns, sizeof(stub_insns));
-
- /* Stub uses address relative to kernel toc (from the paca) */
- reladdr = addr - kernel_toc_addr();
- if (reladdr > 0x7FFFFFFF || reladdr < -(0x80000000L)) {
- pr_err("%s: Address of %ps out of range of kernel_toc.\n",
- me->name, (void *)addr);
- return 0;
- }
-
- entry->jump[1] |= PPC_HA(reladdr);
- entry->jump[2] |= PPC_LO(reladdr);
-
- /* Eventhough we don't use funcdata in the stub, it's needed elsewhere. */
- entry->funcdata = func_desc(addr);
- entry->magic = STUB_MAGIC;
-
- return (unsigned long)entry;
-}
-#else
-static unsigned long create_ftrace_stub(const Elf64_Shdr *sechdrs,
- struct module *me, unsigned long addr)
-{
- return stub_for_addr(sechdrs, addr, me);
-}
-#endif
-
int module_finalize_ftrace(struct module *mod, const Elf_Shdr *sechdrs)
{
- mod->arch.tramp = create_ftrace_stub(sechdrs, mod,
- (unsigned long)ftrace_caller);
+ mod->arch.tramp = stub_for_addr(sechdrs,
+ (unsigned long)ftrace_caller,
+ mod,
+ "ftrace_caller");
#ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
- mod->arch.tramp_regs = create_ftrace_stub(sechdrs, mod,
- (unsigned long)ftrace_regs_caller);
+ mod->arch.tramp_regs = stub_for_addr(sechdrs,
+ (unsigned long)ftrace_regs_caller,
+ mod,
+ "ftrace_regs_caller");
if (!mod->arch.tramp_regs)
return -ENOENT;
#endif
--
2.25.1
^ permalink raw reply related
* [PATCH 2/3] powerpc/module_64: Simplify check for -mprofile-kernel ftrace relocations
From: Naveen N. Rao @ 2020-04-21 17:35 UTC (permalink / raw)
To: linuxppc-dev; +Cc: Qian Cai, Steven Rostedt
In-Reply-To: <cover.1587488954.git.naveen.n.rao@linux.vnet.ibm.com>
For -mprofile-kernel, we need special handling when generating stubs for
ftrace calls such as _mcount(). To faciliate this, we check if a
R_PPC64_REL24 relocation is for a symbol named "_mcount()" along with
also checking the instruction sequence. The latter is not really
required since "_mcount()" is an exported symbol and kernel modules
cannot use it. As such, drop the additional checking and simplify the
code. This helps unify stub creation for ftrace stubs with
-mprofile-kernel and aids in code reuse.
Also rename is_mprofile_mcount_callsite() to is_mprofile_ftrace_call()
to reflect the checking being done.
Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
---
arch/powerpc/kernel/module_64.c | 18 ++++--------------
1 file changed, 4 insertions(+), 14 deletions(-)
diff --git a/arch/powerpc/kernel/module_64.c b/arch/powerpc/kernel/module_64.c
index 54d9d830f4a4..7f4cc5346387 100644
--- a/arch/powerpc/kernel/module_64.c
+++ b/arch/powerpc/kernel/module_64.c
@@ -414,19 +414,9 @@ static unsigned long stub_for_addr(const Elf64_Shdr *sechdrs,
}
#ifdef CONFIG_MPROFILE_KERNEL
-static bool is_mprofile_mcount_callsite(const char *name, u32 *instruction)
+static bool is_mprofile_ftrace_call(const char *name)
{
- if (strcmp("_mcount", name))
- return false;
-
- /*
- * Check if this is one of the -mprofile-kernel sequences.
- */
- if (instruction[-1] == PPC_INST_STD_LR &&
- instruction[-2] == PPC_INST_MFLR)
- return true;
-
- if (instruction[-1] == PPC_INST_MFLR)
+ if (!strcmp("_mcount", name))
return true;
return false;
@@ -450,7 +440,7 @@ static void squash_toc_save_inst(const char *name, unsigned long addr)
#else
static void squash_toc_save_inst(const char *name, unsigned long addr) { }
-static bool is_mprofile_mcount_callsite(const char *name, u32 *instruction)
+static bool is_mprofile_ftrace_call(const char *name)
{
return false;
}
@@ -462,7 +452,7 @@ static int restore_r2(const char *name, u32 *instruction, struct module *me)
{
u32 *prev_insn = instruction - 1;
- if (is_mprofile_mcount_callsite(name, prev_insn))
+ if (is_mprofile_ftrace_call(name))
return 1;
/*
--
2.25.1
^ permalink raw reply related
* [PATCH 1/3] powerpc/module_64: Consolidate ftrace code
From: Naveen N. Rao @ 2020-04-21 17:35 UTC (permalink / raw)
To: linuxppc-dev; +Cc: Qian Cai, Steven Rostedt
In-Reply-To: <cover.1587488954.git.naveen.n.rao@linux.vnet.ibm.com>
module_trampoline_target() is only used by ftrace. Move the prototype
within the appropriate #ifdef in the header. Also, move the function
body to the end of module_64.c so as to consolidate all ftrace code in
one place.
No functional changes.
Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
---
arch/powerpc/include/asm/module.h | 3 --
arch/powerpc/kernel/module_64.c | 69 +++++++++++++++----------------
2 files changed, 33 insertions(+), 39 deletions(-)
diff --git a/arch/powerpc/include/asm/module.h b/arch/powerpc/include/asm/module.h
index 356658711a86..6b99d773f522 100644
--- a/arch/powerpc/include/asm/module.h
+++ b/arch/powerpc/include/asm/module.h
@@ -90,12 +90,9 @@ struct mod_arch_specific {
# ifdef MODULE
asm(".section .ftrace.tramp,\"ax\",@nobits; .align 3; .previous");
# endif /* MODULE */
-#endif
int module_trampoline_target(struct module *mod, unsigned long trampoline,
unsigned long *target);
-
-#ifdef CONFIG_DYNAMIC_FTRACE
int module_finalize_ftrace(struct module *mod, const Elf_Shdr *sechdrs);
#else
static inline int module_finalize_ftrace(struct module *mod, const Elf_Shdr *sechdrs)
diff --git a/arch/powerpc/kernel/module_64.c b/arch/powerpc/kernel/module_64.c
index 007606a48fd9..54d9d830f4a4 100644
--- a/arch/powerpc/kernel/module_64.c
+++ b/arch/powerpc/kernel/module_64.c
@@ -144,42 +144,6 @@ static u32 ppc64_stub_insns[] = {
PPC_INST_BCTR,
};
-#ifdef CONFIG_DYNAMIC_FTRACE
-int module_trampoline_target(struct module *mod, unsigned long addr,
- unsigned long *target)
-{
- struct ppc64_stub_entry *stub;
- func_desc_t funcdata;
- u32 magic;
-
- if (!within_module_core(addr, mod)) {
- pr_err("%s: stub %lx not in module %s\n", __func__, addr, mod->name);
- return -EFAULT;
- }
-
- stub = (struct ppc64_stub_entry *)addr;
-
- if (probe_kernel_read(&magic, &stub->magic, sizeof(magic))) {
- pr_err("%s: fault reading magic for stub %lx for %s\n", __func__, addr, mod->name);
- return -EFAULT;
- }
-
- if (magic != STUB_MAGIC) {
- pr_err("%s: bad magic for stub %lx for %s\n", __func__, addr, mod->name);
- return -EFAULT;
- }
-
- if (probe_kernel_read(&funcdata, &stub->funcdata, sizeof(funcdata))) {
- pr_err("%s: fault reading funcdata for stub %lx for %s\n", __func__, addr, mod->name);
- return -EFAULT;
- }
-
- *target = stub_func_addr(funcdata);
-
- return 0;
-}
-#endif
-
/* Count how many different 24-bit relocations (different symbol,
different addend) */
static unsigned int count_relocs(const Elf64_Rela *rela, unsigned int num)
@@ -745,6 +709,39 @@ int apply_relocate_add(Elf64_Shdr *sechdrs,
}
#ifdef CONFIG_DYNAMIC_FTRACE
+int module_trampoline_target(struct module *mod, unsigned long addr,
+ unsigned long *target)
+{
+ struct ppc64_stub_entry *stub;
+ func_desc_t funcdata;
+ u32 magic;
+
+ if (!within_module_core(addr, mod)) {
+ pr_err("%s: stub %lx not in module %s\n", __func__, addr, mod->name);
+ return -EFAULT;
+ }
+
+ stub = (struct ppc64_stub_entry *)addr;
+
+ if (probe_kernel_read(&magic, &stub->magic, sizeof(magic))) {
+ pr_err("%s: fault reading magic for stub %lx for %s\n", __func__, addr, mod->name);
+ return -EFAULT;
+ }
+
+ if (magic != STUB_MAGIC) {
+ pr_err("%s: bad magic for stub %lx for %s\n", __func__, addr, mod->name);
+ return -EFAULT;
+ }
+
+ if (probe_kernel_read(&funcdata, &stub->funcdata, sizeof(funcdata))) {
+ pr_err("%s: fault reading funcdata for stub %lx for %s\n", __func__, addr, mod->name);
+ return -EFAULT;
+ }
+
+ *target = stub_func_addr(funcdata);
+
+ return 0;
+}
#ifdef CONFIG_MPROFILE_KERNEL
--
2.25.1
^ permalink raw reply related
* [PATCH 0/3] powerpc/module_64: Fix _mcount() stub
From: Naveen N. Rao @ 2020-04-21 17:35 UTC (permalink / raw)
To: linuxppc-dev; +Cc: Qian Cai, Steven Rostedt
This series addresses the crash reported by Qian Cai on ppc64le with
-mprofile-kernel here:
https://lore.kernel.org/r/15AC5B0E-A221-4B8C-9039-FA96B8EF7C88@lca.pw
While fixing patch_instruction() should address the crash, we should
still change the default stub we setup for _mcount() for cases where a
kernel is built without ftrace.
- Naveen
Naveen N. Rao (3):
powerpc/module_64: Consolidate ftrace code
powerpc/module_64: Simplify check for -mprofile-kernel ftrace
relocations
powerpc/module_64: Use special stub for _mcount() with
-mprofile-kernel
arch/powerpc/include/asm/module.h | 3 -
arch/powerpc/kernel/module_64.c | 281 ++++++++++++++----------------
2 files changed, 127 insertions(+), 157 deletions(-)
base-commit: a9aa21d05c33c556e48c5062b6632a9b94906570
--
2.25.1
^ permalink raw reply
* [PATCH v2 24/29] docs: filesystems: convert spufs/spufs.txt to ReST
From: Mauro Carvalho Chehab @ 2020-04-21 16:54 UTC (permalink / raw)
To: Linux Doc Mailing List
Cc: Mauro Carvalho Chehab, Jeremy Kerr, linuxppc-dev, linux-kernel,
Jonathan Corbet
In-Reply-To: <cover.1587487612.git.mchehab+huawei@kernel.org>
This file is at groff output format. Manually convert it to
ReST format, trying to preserve a similar output after parsed.
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
---
Documentation/filesystems/spufs/index.rst | 1 +
.../spufs/{spufs.txt => spufs.rst} | 59 +++++++++----------
MAINTAINERS | 2 +-
3 files changed, 30 insertions(+), 32 deletions(-)
rename Documentation/filesystems/spufs/{spufs.txt => spufs.rst} (95%)
diff --git a/Documentation/filesystems/spufs/index.rst b/Documentation/filesystems/spufs/index.rst
index 39553c6ebefd..939cf59a7d9e 100644
--- a/Documentation/filesystems/spufs/index.rst
+++ b/Documentation/filesystems/spufs/index.rst
@@ -8,4 +8,5 @@ SPU Filesystem
.. toctree::
:maxdepth: 1
+ spufs
spu_create
diff --git a/Documentation/filesystems/spufs/spufs.txt b/Documentation/filesystems/spufs/spufs.rst
similarity index 95%
rename from Documentation/filesystems/spufs/spufs.txt
rename to Documentation/filesystems/spufs/spufs.rst
index caf36aaae804..8a42859bb100 100644
--- a/Documentation/filesystems/spufs/spufs.txt
+++ b/Documentation/filesystems/spufs/spufs.rst
@@ -1,12 +1,18 @@
-SPUFS(2) Linux Programmer's Manual SPUFS(2)
+.. SPDX-License-Identifier: GPL-2.0
+=====
+spufs
+=====
+Name
+====
-NAME
spufs - the SPU file system
-DESCRIPTION
+Description
+===========
+
The SPU file system is used on PowerPC machines that implement the Cell
Broadband Engine Architecture in order to access Synergistic Processor
Units (SPUs).
@@ -21,7 +27,9 @@ DESCRIPTION
ally add or remove files.
-MOUNT OPTIONS
+Mount Options
+=============
+
uid=<uid>
set the user owning the mount point, the default is 0 (root).
@@ -29,7 +37,9 @@ MOUNT OPTIONS
set the group owning the mount point, the default is 0 (root).
-FILES
+Files
+=====
+
The files in spufs mostly follow the standard behavior for regular sys-
tem calls like read(2) or write(2), but often support only a subset of
the operations supported on regular file systems. This list details the
@@ -125,14 +135,12 @@ FILES
space is available for writing.
- /mbox_stat
- /ibox_stat
- /wbox_stat
+ /mbox_stat, /ibox_stat, /wbox_stat
Read-only files that contain the length of the current queue, i.e. how
many words can be read from mbox or ibox or how many words can be
written to wbox without blocking. The files can be read only in 4-byte
units and return a big-endian binary integer number. The possible
- operations on an open *box_stat file are:
+ operations on an open ``*box_stat`` file are:
read(2)
If a count smaller than four is requested, read returns -1 and
@@ -143,12 +151,7 @@ FILES
in EAGAIN.
- /npc
- /decr
- /decr_status
- /spu_tag_mask
- /event_mask
- /srr0
+ /npc, /decr, /decr_status, /spu_tag_mask, /event_mask, /srr0
Internal registers of the SPU. The representation is an ASCII string
with the numeric value of the next instruction to be executed. These
can be used in read/write mode for debugging, but normal operation of
@@ -157,17 +160,14 @@ FILES
The contents of these files are:
+ =================== ===================================
npc Next Program Counter
-
decr SPU Decrementer
-
decr_status Decrementer Status
-
spu_tag_mask MFC tag mask for SPU DMA
-
event_mask Event mask for SPU interrupts
-
srr0 Interrupt Return address register
+ =================== ===================================
The possible operations on an open npc, decr, decr_status,
@@ -206,8 +206,7 @@ FILES
from the data buffer, updating the value of the fpcr register.
- /signal1
- /signal2
+ /signal1, /signal2
The two signal notification channels of an SPU. These are read-write
files that operate on a 32 bit word. Writing to one of these files
triggers an interrupt on the SPU. The value written to the signal
@@ -233,8 +232,7 @@ FILES
file.
- /signal1_type
- /signal2_type
+ /signal1_type, /signal2_type
These two files change the behavior of the signal1 and signal2 notifi-
cation files. The contain a numerical ASCII string which is read as
either "1" or "0". In mode 0 (overwrite), the hardware replaces the
@@ -259,18 +257,17 @@ FILES
the previous setting.
-EXAMPLES
+Examples
+========
/etc/fstab entry
none /spu spufs gid=spu 0 0
-AUTHORS
+Authors
+=======
Arnd Bergmann <arndb@de.ibm.com>, Mark Nutter <mnutter@us.ibm.com>,
Ulrich Weigand <Ulrich.Weigand@de.ibm.com>
-SEE ALSO
+See Also
+========
capabilities(7), close(2), spu_create(2), spu_run(2), spufs(7)
-
-
-
-Linux 2005-09-28 SPUFS(2)
diff --git a/MAINTAINERS b/MAINTAINERS
index ac8ddd91928a..968c97eda352 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -15955,7 +15955,7 @@ M: Jeremy Kerr <jk@ozlabs.org>
L: linuxppc-dev@lists.ozlabs.org
S: Supported
W: http://www.ibm.com/developerworks/power/cell/
-F: Documentation/filesystems/spufs.txt
+F: Documentation/filesystems/spufs/spufs.rst
F: arch/powerpc/platforms/cell/spufs/
SQUASHFS FILE SYSTEM
--
2.25.2
^ permalink raw reply related
* [PATCH v2 00/29] fs: convert remaining docs to ReST file format
From: Mauro Carvalho Chehab @ 2020-04-21 16:54 UTC (permalink / raw)
To: Linux Doc Mailing List
Cc: linux-usb, Jan Kara, Amir Goldstein, J. Bruce Fields,
Christoph Hellwig, Jonathan Corbet, Mauro Carvalho Chehab,
codalist, coda, linux-cachefs, Alexey Dobriyan, Joel Becker,
Jan Harkes, David Howells, Greg Kroah-Hartman, Darrick J. Wong,
Jeff Layton, linux-kernel, linux-xfs, Jeremy Kerr, Jan Kara,
linux-fsdevel, linuxppc-dev, Alexander Viro
This patch series convert the remaining files under Documentation/filesystems
to the ReST file format (except for dax.txt and patch-lookup.txt).
It is based on linux-next (next-2020021).
PS.: I opted to add mainly ML from the output of get_maintainers.pl to the c/c
list of patch 00/34, because otherwise the number of c/c would be too many,
with would very likely cause ML servers to reject it.
The results of those changes (together with other changes from my pending
doc patches) are available at:
https://www.infradead.org/~mchehab/kernel_docs/filesystems/index.html
And the series is also on my git tree:
https://git.linuxtv.org/mchehab/experimental.git/log/?h=fs_docs
If you prefer, feel free to merge the patches via the filesystems git tree(s).
-
v2:
- Removed dax.txt, in order to prevent a merge conflict with a dax patchset;
- Removed patch-lookup.txt conversion, due to patch-lookup.rst.
(I'll revisit this on some future)
- Removed a patch that was already merged;
- Added some Acked-by.
Mauro Carvalho Chehab (29):
docs: filesystems: convert caching/object.txt to ReST
docs: filesystems: convert caching/fscache.txt to ReST format
docs: filesystems: caching/netfs-api.txt: convert it to ReST
docs: filesystems: caching/operations.txt: convert it to ReST
docs: filesystems: caching/cachefiles.txt: convert to ReST
docs: filesystems: caching/backend-api.txt: convert it to ReST
docs: filesystems: convert cifs/cifsroot.txt to ReST
docs: filesystems: convert configfs.txt to ReST
docs: filesystems: convert automount-support.txt to ReST
docs: filesystems: convert coda.txt to ReST
docs: filesystems: convert devpts.txt to ReST
docs: filesystems: convert dnotify.txt to ReST
docs: filesystems: convert fiemap.txt to ReST
docs: filesystems: convert files.txt to ReST
docs: filesystems: convert fuse-io.txt to ReST
docs: filesystems: convert locks.txt to ReST
docs: filesystems: convert mandatory-locking.txt to ReST
docs: filesystems: convert mount_api.txt to ReST
docs: filesystems: convert quota.txt to ReST
docs: filesystems: convert seq_file.txt to ReST
docs: filesystems: convert sharedsubtree.txt to ReST
docs: filesystems: split spufs.txt into 3 separate files
docs: filesystems: convert spufs/spu_create.txt to ReST
docs: filesystems: convert spufs/spufs.txt to ReST
docs: filesystems: convert spufs/spu_run.txt to ReST
docs: filesystems: convert sysfs-pci.txt to ReST
docs: filesystems: convert sysfs-tagging.txt to ReST
docs: filesystems: convert xfs-delayed-logging-design.txt to ReST
docs: filesystems: convert xfs-self-describing-metadata.txt to ReST
Documentation/admin-guide/sysctl/kernel.rst | 2 +-
...ount-support.txt => automount-support.rst} | 23 +-
.../{backend-api.txt => backend-api.rst} | 165 +-
.../{cachefiles.txt => cachefiles.rst} | 139 +-
Documentation/filesystems/caching/fscache.rst | 565 ++++++
Documentation/filesystems/caching/fscache.txt | 448 -----
Documentation/filesystems/caching/index.rst | 14 +
.../caching/{netfs-api.txt => netfs-api.rst} | 172 +-
.../caching/{object.txt => object.rst} | 43 +-
.../{operations.txt => operations.rst} | 45 +-
.../cifs/{cifsroot.txt => cifsroot.rst} | 56 +-
Documentation/filesystems/coda.rst | 1670 ++++++++++++++++
Documentation/filesystems/coda.txt | 1676 -----------------
.../{configfs/configfs.txt => configfs.rst} | 129 +-
Documentation/filesystems/devpts.rst | 36 +
Documentation/filesystems/devpts.txt | 26 -
.../filesystems/{dnotify.txt => dnotify.rst} | 11 +-
.../filesystems/{fiemap.txt => fiemap.rst} | 133 +-
.../filesystems/{files.txt => files.rst} | 15 +-
.../filesystems/{fuse-io.txt => fuse-io.rst} | 6 +
Documentation/filesystems/index.rst | 23 +
.../filesystems/{locks.txt => locks.rst} | 14 +-
...tory-locking.txt => mandatory-locking.rst} | 25 +-
.../{mount_api.txt => mount_api.rst} | 329 ++--
Documentation/filesystems/proc.rst | 2 +-
.../filesystems/{quota.txt => quota.rst} | 41 +-
.../{seq_file.txt => seq_file.rst} | 61 +-
.../{sharedsubtree.txt => sharedsubtree.rst} | 394 ++--
Documentation/filesystems/spufs/index.rst | 13 +
.../filesystems/spufs/spu_create.rst | 131 ++
Documentation/filesystems/spufs/spu_run.rst | 138 ++
.../{spufs.txt => spufs/spufs.rst} | 304 +--
.../{sysfs-pci.txt => sysfs-pci.rst} | 23 +-
.../{sysfs-tagging.txt => sysfs-tagging.rst} | 22 +-
...ign.txt => xfs-delayed-logging-design.rst} | 65 +-
...a.txt => xfs-self-describing-metadata.rst} | 182 +-
Documentation/iio/iio_configfs.rst | 2 +-
Documentation/usb/gadget_configfs.rst | 4 +-
MAINTAINERS | 14 +-
fs/cachefiles/Kconfig | 4 +-
fs/coda/Kconfig | 2 +-
fs/configfs/inode.c | 2 +-
fs/configfs/item.c | 2 +-
fs/fscache/Kconfig | 8 +-
fs/fscache/cache.c | 8 +-
fs/fscache/cookie.c | 2 +-
fs/fscache/object.c | 4 +-
fs/fscache/operation.c | 2 +-
fs/locks.c | 2 +-
include/linux/configfs.h | 2 +-
include/linux/fs_context.h | 2 +-
include/linux/fscache-cache.h | 4 +-
include/linux/fscache.h | 42 +-
include/linux/lsm_hooks.h | 2 +-
54 files changed, 3844 insertions(+), 3405 deletions(-)
rename Documentation/filesystems/{automount-support.txt => automount-support.rst} (92%)
rename Documentation/filesystems/caching/{backend-api.txt => backend-api.rst} (87%)
rename Documentation/filesystems/caching/{cachefiles.txt => cachefiles.rst} (90%)
create mode 100644 Documentation/filesystems/caching/fscache.rst
delete mode 100644 Documentation/filesystems/caching/fscache.txt
create mode 100644 Documentation/filesystems/caching/index.rst
rename Documentation/filesystems/caching/{netfs-api.txt => netfs-api.rst} (91%)
rename Documentation/filesystems/caching/{object.txt => object.rst} (95%)
rename Documentation/filesystems/caching/{operations.txt => operations.rst} (90%)
rename Documentation/filesystems/cifs/{cifsroot.txt => cifsroot.rst} (72%)
create mode 100644 Documentation/filesystems/coda.rst
delete mode 100644 Documentation/filesystems/coda.txt
rename Documentation/filesystems/{configfs/configfs.txt => configfs.rst} (87%)
create mode 100644 Documentation/filesystems/devpts.rst
delete mode 100644 Documentation/filesystems/devpts.txt
rename Documentation/filesystems/{dnotify.txt => dnotify.rst} (90%)
rename Documentation/filesystems/{fiemap.txt => fiemap.rst} (70%)
rename Documentation/filesystems/{files.txt => files.rst} (95%)
rename Documentation/filesystems/{fuse-io.txt => fuse-io.rst} (95%)
rename Documentation/filesystems/{locks.txt => locks.rst} (91%)
rename Documentation/filesystems/{mandatory-locking.txt => mandatory-locking.rst} (91%)
rename Documentation/filesystems/{mount_api.txt => mount_api.rst} (79%)
rename Documentation/filesystems/{quota.txt => quota.rst} (81%)
rename Documentation/filesystems/{seq_file.txt => seq_file.rst} (92%)
rename Documentation/filesystems/{sharedsubtree.txt => sharedsubtree.rst} (72%)
create mode 100644 Documentation/filesystems/spufs/index.rst
create mode 100644 Documentation/filesystems/spufs/spu_create.rst
create mode 100644 Documentation/filesystems/spufs/spu_run.rst
rename Documentation/filesystems/{spufs.txt => spufs/spufs.rst} (57%)
rename Documentation/filesystems/{sysfs-pci.txt => sysfs-pci.rst} (92%)
rename Documentation/filesystems/{sysfs-tagging.txt => sysfs-tagging.rst} (72%)
rename Documentation/filesystems/{xfs-delayed-logging-design.txt => xfs-delayed-logging-design.rst} (97%)
rename Documentation/filesystems/{xfs-self-describing-metadata.txt => xfs-self-describing-metadata.rst} (83%)
--
2.25.2
^ permalink raw reply
* RE: [musl] Powerpc Linux 'scv' system call ABI proposal take 2
From: David Laight @ 2020-04-21 12:28 UTC (permalink / raw)
To: 'Nicholas Piggin', Adhemerval Zanella, Rich Felker
Cc: libc-dev@lists.llvm.org, libc-alpha@sourceware.org,
linuxppc-dev@lists.ozlabs.org, musl@lists.openwall.com
In-Reply-To: <1587344003.daumxvs1kh.astroid@bobo.none>
From: Nicholas Piggin
> Sent: 20 April 2020 02:10
...
> >> Yes, but does it really matter to optimize this specific usage case
> >> for size? glibc, for instance, tries to leverage the syscall mechanism
> >> by adding some complex pre-processor asm directives. It optimizes
> >> the syscall code size in most cases. For instance, kill in static case
> >> generates on x86_64:
> >>
> >> 0000000000000000 <__kill>:
> >> 0: b8 3e 00 00 00 mov $0x3e,%eax
> >> 5: 0f 05 syscall
> >> 7: 48 3d 01 f0 ff ff cmp $0xfffffffffffff001,%rax
> >> d: 0f 83 00 00 00 00 jae 13 <__kill+0x13>
Hmmm... that cmp + jae is unnecessary here.
It is also a 32bit offset jump.
I also suspect it gets predicted very badly.
> >> 13: c3 retq
> >>
> >> While on musl:
> >>
> >> 0000000000000000 <kill>:
> >> 0: 48 83 ec 08 sub $0x8,%rsp
> >> 4: 48 63 ff movslq %edi,%rdi
> >> 7: 48 63 f6 movslq %esi,%rsi
> >> a: b8 3e 00 00 00 mov $0x3e,%eax
> >> f: 0f 05 syscall
> >> 11: 48 89 c7 mov %rax,%rdi
> >> 14: e8 00 00 00 00 callq 19 <kill+0x19>
> >> 19: 5a pop %rdx
> >> 1a: c3 retq
> >
> > Wow that's some extraordinarily bad codegen going on by gcc... The
> > sign-extension is semantically needed and I don't see a good way
> > around it (glibc's asm is kinda a hack taking advantage of kernel not
> > looking at high bits, I think), but the gratuitous stack adjustment
> > and refusal to generate a tail call isn't. I'll see if we can track
> > down what's going on and get it fixed.
A suitable cast might get rid of the sign extension.
Possibly just (unsigned int).
David
-
Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK
Registration No: 1397386 (Wales)
^ permalink raw reply
* Re: [PATCH 2/5] powerpc: Replace _ALIGN_DOWN() by ALIGN_DOWN()
From: Segher Boessenkool @ 2020-04-21 15:55 UTC (permalink / raw)
To: Joel Stanley
Cc: linux-fbdev, kvm, Linux Kernel Mailing List, dri-devel,
Paul Mackerras, alsa-devel, linuxppc-dev
In-Reply-To: <CACPK8XfqnqgkXcBzp=nqd=AJX1MK05eTNiyOdaEuRu3_6RsXSQ@mail.gmail.com>
Hi!
On Tue, Apr 21, 2020 at 01:04:05AM +0000, Joel Stanley wrote:
> On Mon, 20 Apr 2020 at 18:38, Christophe Leroy <christophe.leroy@c-s.fr> wrote:
> > _ALIGN_DOWN() is specific to powerpc
> > ALIGN_DOWN() is generic and does the same
> >
> > Replace _ALIGN_DOWN() by ALIGN_DOWN()
>
> This one is a bit less obvious. It becomes (leaving the typeof's alone
> for clarity):
>
> -((addr)&(~((typeof(addr))(size)-1)))
> +((((addr) - ((size) - 1)) + ((typeof(addr))(size) - 1)) &
> ~((typeof(addr))(size)-1))
>
> Which I assume the compiler will sort out?
[ This is line-wrapped, something in your mailer? Took me a bit to figure
out the - and + are diff -u things :-) ]
In the common case where size is a constant integer power of two, the
compiler will have no problem with this. But why do so complicated?
Why are the casts there, btw?
Segher
^ permalink raw reply
* [PATCH 7/7] exec: open code copy_string_kernel
From: Christoph Hellwig @ 2020-04-21 15:42 UTC (permalink / raw)
To: Andrew Morton, Alexander Viro
Cc: Arnd Bergmann, linux-kernel, Jeremy Kerr, linux-fsdevel,
linuxppc-dev, Eric W . Biederman
In-Reply-To: <20200421154204.252921-1-hch@lst.de>
Currently copy_string_kernel is just a wrapper around copy_strings that
simplifies the calling conventions and uses set_fs to allow passing a
kernel pointer. But due to the fact the we only need to handle a single
kernel argument pointer, the logic can be sigificantly simplified while
getting rid of the set_fs.
Signed-off-by: Christoph Hellwig <hch@lst.de>
---
fs/exec.c | 43 ++++++++++++++++++++++++++++++++++---------
1 file changed, 34 insertions(+), 9 deletions(-)
diff --git a/fs/exec.c b/fs/exec.c
index b2a77d5acede..ea90af1fb236 100644
--- a/fs/exec.c
+++ b/fs/exec.c
@@ -592,17 +592,42 @@ static int copy_strings(int argc, struct user_arg_ptr argv,
*/
int copy_string_kernel(const char *arg, struct linux_binprm *bprm)
{
- int r;
- mm_segment_t oldfs = get_fs();
- struct user_arg_ptr argv = {
- .ptr.native = (const char __user *const __user *)&arg,
- };
+ int len = strnlen(arg, MAX_ARG_STRLEN) + 1 /* terminating NUL */;
+ unsigned long pos = bprm->p;
+
+ if (len == 0)
+ return -EFAULT;
+ if (!valid_arg_len(bprm, len))
+ return -E2BIG;
+
+ /* We're going to work our way backwards. */
+ arg += len;
+ bprm->p -= len;
+ if (IS_ENABLED(CONFIG_MMU) && bprm->p < bprm->argmin)
+ return -E2BIG;
+
+ while (len > 0) {
+ unsigned int bytes_to_copy = min_t(unsigned int, len,
+ min_not_zero(offset_in_page(pos), PAGE_SIZE));
+ struct page *page;
+ char *kaddr;
- set_fs(KERNEL_DS);
- r = copy_strings(1, argv, bprm);
- set_fs(oldfs);
+ pos -= bytes_to_copy;
+ arg -= bytes_to_copy;
+ len -= bytes_to_copy;
- return r;
+ page = get_arg_page(bprm, pos, 1);
+ if (!page)
+ return -E2BIG;
+ kaddr = kmap_atomic(page);
+ flush_arg_page(bprm, pos & PAGE_MASK, page);
+ memcpy(kaddr + offset_in_page(pos), arg, bytes_to_copy);
+ flush_kernel_dcache_page(page);
+ kunmap_atomic(kaddr);
+ put_arg_page(page);
+ }
+
+ return 0;
}
EXPORT_SYMBOL(copy_string_kernel);
--
2.26.1
^ permalink raw reply related
* [PATCH 6/7] exec: simplify the copy_strings_kernel calling convention
From: Christoph Hellwig @ 2020-04-21 15:42 UTC (permalink / raw)
To: Andrew Morton, Alexander Viro
Cc: Arnd Bergmann, linux-kernel, Jeremy Kerr, linux-fsdevel,
linuxppc-dev, Eric W . Biederman
In-Reply-To: <20200421154204.252921-1-hch@lst.de>
copy_strings_kernel is always used with a single argument,
adjust the calling convention to that.
Signed-off-by: Christoph Hellwig <hch@lst.de>
---
fs/binfmt_em86.c | 6 +++---
fs/binfmt_misc.c | 4 ++--
fs/binfmt_script.c | 6 +++---
fs/exec.c | 13 ++++++-------
include/linux/binfmts.h | 3 +--
5 files changed, 15 insertions(+), 17 deletions(-)
diff --git a/fs/binfmt_em86.c b/fs/binfmt_em86.c
index 466497860c62..f33fa668c91f 100644
--- a/fs/binfmt_em86.c
+++ b/fs/binfmt_em86.c
@@ -68,15 +68,15 @@ static int load_em86(struct linux_binprm *bprm)
* user environment and arguments are stored.
*/
remove_arg_zero(bprm);
- retval = copy_strings_kernel(1, &bprm->filename, bprm);
+ retval = copy_string_kernel(bprm->filename, bprm);
if (retval < 0) return retval;
bprm->argc++;
if (i_arg) {
- retval = copy_strings_kernel(1, &i_arg, bprm);
+ retval = copy_string_kernel(i_arg, bprm);
if (retval < 0) return retval;
bprm->argc++;
}
- retval = copy_strings_kernel(1, &i_name, bprm);
+ retval = copy_string_kernel(i_name, bprm);
if (retval < 0) return retval;
bprm->argc++;
diff --git a/fs/binfmt_misc.c b/fs/binfmt_misc.c
index cdb45829354d..b15257d8ff5e 100644
--- a/fs/binfmt_misc.c
+++ b/fs/binfmt_misc.c
@@ -190,13 +190,13 @@ static int load_misc_binary(struct linux_binprm *bprm)
bprm->file = NULL;
}
/* make argv[1] be the path to the binary */
- retval = copy_strings_kernel(1, &bprm->interp, bprm);
+ retval = copy_string_kernel(bprm->interp, bprm);
if (retval < 0)
goto error;
bprm->argc++;
/* add the interp as argv[0] */
- retval = copy_strings_kernel(1, &fmt->interpreter, bprm);
+ retval = copy_string_kernel(fmt->interpreter, bprm);
if (retval < 0)
goto error;
bprm->argc++;
diff --git a/fs/binfmt_script.c b/fs/binfmt_script.c
index e9e6a6f4a35f..c4fb7f52a46e 100644
--- a/fs/binfmt_script.c
+++ b/fs/binfmt_script.c
@@ -117,17 +117,17 @@ static int load_script(struct linux_binprm *bprm)
retval = remove_arg_zero(bprm);
if (retval)
return retval;
- retval = copy_strings_kernel(1, &bprm->interp, bprm);
+ retval = copy_string_kernel(bprm->interp, bprm);
if (retval < 0)
return retval;
bprm->argc++;
if (i_arg) {
- retval = copy_strings_kernel(1, &i_arg, bprm);
+ retval = copy_string_kernel(i_arg, bprm);
if (retval < 0)
return retval;
bprm->argc++;
}
- retval = copy_strings_kernel(1, &i_name, bprm);
+ retval = copy_string_kernel(i_name, bprm);
if (retval)
return retval;
bprm->argc++;
diff --git a/fs/exec.c b/fs/exec.c
index 06b4c550af5d..b2a77d5acede 100644
--- a/fs/exec.c
+++ b/fs/exec.c
@@ -588,24 +588,23 @@ static int copy_strings(int argc, struct user_arg_ptr argv,
}
/*
- * Like copy_strings, but get argv and its values from kernel memory.
+ * Copy and argument/environment string from the kernel to the processes stack.
*/
-int copy_strings_kernel(int argc, const char *const *__argv,
- struct linux_binprm *bprm)
+int copy_string_kernel(const char *arg, struct linux_binprm *bprm)
{
int r;
mm_segment_t oldfs = get_fs();
struct user_arg_ptr argv = {
- .ptr.native = (const char __user *const __user *)__argv,
+ .ptr.native = (const char __user *const __user *)&arg,
};
set_fs(KERNEL_DS);
- r = copy_strings(argc, argv, bprm);
+ r = copy_strings(1, argv, bprm);
set_fs(oldfs);
return r;
}
-EXPORT_SYMBOL(copy_strings_kernel);
+EXPORT_SYMBOL(copy_string_kernel);
#ifdef CONFIG_MMU
@@ -1863,7 +1862,7 @@ static int __do_execve_file(int fd, struct filename *filename,
if (retval < 0)
goto out;
- retval = copy_strings_kernel(1, &bprm->filename, bprm);
+ retval = copy_string_kernel(bprm->filename, bprm);
if (retval < 0)
goto out;
diff --git a/include/linux/binfmts.h b/include/linux/binfmts.h
index a345d9fed3d8..3d3afe094c97 100644
--- a/include/linux/binfmts.h
+++ b/include/linux/binfmts.h
@@ -144,8 +144,7 @@ extern int setup_arg_pages(struct linux_binprm * bprm,
extern int transfer_args_to_stack(struct linux_binprm *bprm,
unsigned long *sp_location);
extern int bprm_change_interp(const char *interp, struct linux_binprm *bprm);
-extern int copy_strings_kernel(int argc, const char *const *argv,
- struct linux_binprm *bprm);
+int copy_string_kernel(const char *arg, struct linux_binprm *bprm);
extern void install_exec_creds(struct linux_binprm *bprm);
extern void set_binfmt(struct linux_binfmt *new);
extern ssize_t read_code(struct file *, unsigned long, loff_t, size_t);
--
2.26.1
^ permalink raw reply related
* [PATCH 5/7] binfmt_elf_fdpic: remove the set_fs(KERNEL_DS) in elf_fdpic_core_dump
From: Christoph Hellwig @ 2020-04-21 15:42 UTC (permalink / raw)
To: Andrew Morton, Alexander Viro
Cc: Arnd Bergmann, linux-kernel, Jeremy Kerr, linux-fsdevel,
linuxppc-dev, Eric W . Biederman
In-Reply-To: <20200421154204.252921-1-hch@lst.de>
There is no logic in elf_fdpic_core_dump itself, or in the various arch
helpers called from it which use uaccess routines on kernel pointers
except for the file writes thate are nicely encapsulated by using
__kernel_write in dump_emit.
Signed-off-by: Christoph Hellwig <hch@lst.de>
---
fs/binfmt_elf_fdpic.c | 31 ++++++++++++-------------------
1 file changed, 12 insertions(+), 19 deletions(-)
diff --git a/fs/binfmt_elf_fdpic.c b/fs/binfmt_elf_fdpic.c
index 240f66663543..c62c17a5c34a 100644
--- a/fs/binfmt_elf_fdpic.c
+++ b/fs/binfmt_elf_fdpic.c
@@ -1549,7 +1549,6 @@ static int elf_fdpic_core_dump(struct coredump_params *cprm)
{
#define NUM_NOTES 6
int has_dumped = 0;
- mm_segment_t fs;
int segs;
int i;
struct vm_area_struct *vma;
@@ -1678,9 +1677,6 @@ static int elf_fdpic_core_dump(struct coredump_params *cprm)
"LINUX", ELF_CORE_XFPREG_TYPE, sizeof(*xfpu), xfpu);
#endif
- fs = get_fs();
- set_fs(KERNEL_DS);
-
offset += sizeof(*elf); /* Elf header */
offset += segs * sizeof(struct elf_phdr); /* Program headers */
@@ -1695,7 +1691,7 @@ static int elf_fdpic_core_dump(struct coredump_params *cprm)
phdr4note = kmalloc(sizeof(*phdr4note), GFP_KERNEL);
if (!phdr4note)
- goto end_coredump;
+ goto cleanup;
fill_elf_note_phdr(phdr4note, sz, offset);
offset += sz;
@@ -1711,17 +1707,17 @@ static int elf_fdpic_core_dump(struct coredump_params *cprm)
if (e_phnum == PN_XNUM) {
shdr4extnum = kmalloc(sizeof(*shdr4extnum), GFP_KERNEL);
if (!shdr4extnum)
- goto end_coredump;
+ goto cleanup;
fill_extnum_info(elf, shdr4extnum, e_shoff, segs);
}
offset = dataoff;
if (!dump_emit(cprm, elf, sizeof(*elf)))
- goto end_coredump;
+ goto cleanup;
if (!dump_emit(cprm, phdr4note, sizeof(*phdr4note)))
- goto end_coredump;
+ goto cleanup;
/* write program headers for segments dump */
for (vma = current->mm->mmap; vma; vma = vma->vm_next) {
@@ -1745,16 +1741,16 @@ static int elf_fdpic_core_dump(struct coredump_params *cprm)
phdr.p_align = ELF_EXEC_PAGESIZE;
if (!dump_emit(cprm, &phdr, sizeof(phdr)))
- goto end_coredump;
+ goto cleanup;
}
if (!elf_core_write_extra_phdrs(cprm, offset))
- goto end_coredump;
+ goto cleanup;
/* write out the notes section */
for (i = 0; i < numnote; i++)
if (!writenote(notes + i, cprm))
- goto end_coredump;
+ goto cleanup;
/* write out the thread status notes section */
list_for_each(t, &thread_list) {
@@ -1763,21 +1759,21 @@ static int elf_fdpic_core_dump(struct coredump_params *cprm)
for (i = 0; i < tmp->num_notes; i++)
if (!writenote(&tmp->notes[i], cprm))
- goto end_coredump;
+ goto cleanup;
}
if (!dump_skip(cprm, dataoff - cprm->pos))
- goto end_coredump;
+ goto cleanup;
if (!elf_fdpic_dump_segments(cprm))
- goto end_coredump;
+ goto cleanup;
if (!elf_core_write_extra_data(cprm))
- goto end_coredump;
+ goto cleanup;
if (e_phnum == PN_XNUM) {
if (!dump_emit(cprm, shdr4extnum, sizeof(*shdr4extnum)))
- goto end_coredump;
+ goto cleanup;
}
if (cprm->file->f_pos != offset) {
@@ -1787,9 +1783,6 @@ static int elf_fdpic_core_dump(struct coredump_params *cprm)
cprm->file->f_pos, offset);
}
-end_coredump:
- set_fs(fs);
-
cleanup:
while (!list_empty(&thread_list)) {
struct list_head *tmp = thread_list.next;
--
2.26.1
^ permalink raw reply related
* [PATCH 4/7] binfmt_elf: remove the set_fs(KERNEL_DS) in elf_core_dump
From: Christoph Hellwig @ 2020-04-21 15:42 UTC (permalink / raw)
To: Andrew Morton, Alexander Viro
Cc: Arnd Bergmann, linux-kernel, Jeremy Kerr, linux-fsdevel,
linuxppc-dev, Eric W . Biederman
In-Reply-To: <20200421154204.252921-1-hch@lst.de>
There is no logic in elf_core_dump itself, or in the various arch helpers
called from it which use uaccess routines on kernel pointers except for
the file writes thate are nicely encapsulated by using __kernel_write in
dump_emit.
Signed-off-by: Christoph Hellwig <hch@lst.de>
---
fs/binfmt_elf.c | 40 +++++++++++++---------------------------
1 file changed, 13 insertions(+), 27 deletions(-)
diff --git a/fs/binfmt_elf.c b/fs/binfmt_elf.c
index a1f57e20c3cf..b29b84595b09 100644
--- a/fs/binfmt_elf.c
+++ b/fs/binfmt_elf.c
@@ -1355,7 +1355,6 @@ static unsigned long vma_dump_size(struct vm_area_struct *vma,
vma->vm_pgoff == 0 && (vma->vm_flags & VM_READ)) {
u32 __user *header = (u32 __user *) vma->vm_start;
u32 word;
- mm_segment_t fs = get_fs();
/*
* Doing it this way gets the constant folded by GCC.
*/
@@ -1368,14 +1367,8 @@ static unsigned long vma_dump_size(struct vm_area_struct *vma,
magic.elfmag[EI_MAG1] = ELFMAG1;
magic.elfmag[EI_MAG2] = ELFMAG2;
magic.elfmag[EI_MAG3] = ELFMAG3;
- /*
- * Switch to the user "segment" for get_user(),
- * then put back what elf_core_dump() had in place.
- */
- set_fs(USER_DS);
if (unlikely(get_user(word, header)))
word = 0;
- set_fs(fs);
if (word == magic.cmp)
return PAGE_SIZE;
}
@@ -2183,7 +2176,6 @@ static void fill_extnum_info(struct elfhdr *elf, struct elf_shdr *shdr4extnum,
static int elf_core_dump(struct coredump_params *cprm)
{
int has_dumped = 0;
- mm_segment_t fs;
int segs, i;
size_t vma_data_size = 0;
struct vm_area_struct *vma, *gate_vma;
@@ -2236,9 +2228,6 @@ static int elf_core_dump(struct coredump_params *cprm)
has_dumped = 1;
- fs = get_fs();
- set_fs(KERNEL_DS);
-
offset += sizeof(elf); /* Elf header */
offset += segs * sizeof(struct elf_phdr); /* Program headers */
@@ -2250,7 +2239,7 @@ static int elf_core_dump(struct coredump_params *cprm)
phdr4note = kmalloc(sizeof(*phdr4note), GFP_KERNEL);
if (!phdr4note)
- goto end_coredump;
+ goto cleanup;
fill_elf_note_phdr(phdr4note, sz, offset);
offset += sz;
@@ -2265,7 +2254,7 @@ static int elf_core_dump(struct coredump_params *cprm)
vma_filesz = kvmalloc(array_size(sizeof(*vma_filesz), (segs - 1)),
GFP_KERNEL);
if (!vma_filesz)
- goto end_coredump;
+ goto cleanup;
for (i = 0, vma = first_vma(current, gate_vma); vma != NULL;
vma = next_vma(vma, gate_vma)) {
@@ -2283,17 +2272,17 @@ static int elf_core_dump(struct coredump_params *cprm)
if (e_phnum == PN_XNUM) {
shdr4extnum = kmalloc(sizeof(*shdr4extnum), GFP_KERNEL);
if (!shdr4extnum)
- goto end_coredump;
+ goto cleanup;
fill_extnum_info(&elf, shdr4extnum, e_shoff, segs);
}
offset = dataoff;
if (!dump_emit(cprm, &elf, sizeof(elf)))
- goto end_coredump;
+ goto cleanup;
if (!dump_emit(cprm, phdr4note, sizeof(*phdr4note)))
- goto end_coredump;
+ goto cleanup;
/* Write program headers for segments dump */
for (i = 0, vma = first_vma(current, gate_vma); vma != NULL;
@@ -2315,22 +2304,22 @@ static int elf_core_dump(struct coredump_params *cprm)
phdr.p_align = ELF_EXEC_PAGESIZE;
if (!dump_emit(cprm, &phdr, sizeof(phdr)))
- goto end_coredump;
+ goto cleanup;
}
if (!elf_core_write_extra_phdrs(cprm, offset))
- goto end_coredump;
+ goto cleanup;
/* write out the notes section */
if (!write_note_info(&info, cprm))
- goto end_coredump;
+ goto cleanup;
if (elf_coredump_extra_notes_write(cprm))
- goto end_coredump;
+ goto cleanup;
/* Align to page */
if (!dump_skip(cprm, dataoff - cprm->pos))
- goto end_coredump;
+ goto cleanup;
for (i = 0, vma = first_vma(current, gate_vma); vma != NULL;
vma = next_vma(vma, gate_vma)) {
@@ -2352,22 +2341,19 @@ static int elf_core_dump(struct coredump_params *cprm)
} else
stop = !dump_skip(cprm, PAGE_SIZE);
if (stop)
- goto end_coredump;
+ goto cleanup;
}
}
dump_truncate(cprm);
if (!elf_core_write_extra_data(cprm))
- goto end_coredump;
+ goto cleanup;
if (e_phnum == PN_XNUM) {
if (!dump_emit(cprm, shdr4extnum, sizeof(*shdr4extnum)))
- goto end_coredump;
+ goto cleanup;
}
-end_coredump:
- set_fs(fs);
-
cleanup:
free_note_info(&info);
kfree(shdr4extnum);
--
2.26.1
^ permalink raw reply related
* [PATCH 3/7] binfmt_elf: femove the set_fs in fill_siginfo_note
From: Christoph Hellwig @ 2020-04-21 15:42 UTC (permalink / raw)
To: Andrew Morton, Alexander Viro
Cc: Arnd Bergmann, linux-kernel, Jeremy Kerr, linux-fsdevel,
linuxppc-dev, Eric W . Biederman
In-Reply-To: <20200421154204.252921-1-hch@lst.de>
From: "Eric W. Biederman" <ebiederm@xmission.com>
The code in binfmt_elf.c is differnt from the rest of the code that
processes siginfo, as it sends siginfo from a kernel buffer to a file
rather than from kernel memory to userspace buffers. To remove it's
use of set_fs the code needs some different siginfo helpers.
Add the helper copy_siginfo_to_external to copy from the kernel's
internal siginfo layout to a buffer in the siginfo layout that
userspace expects.
Modify fill_siginfo_note to use copy_siginfo_to_external instead of
set_fs and copy_siginfo_to_user.
Update compat_binfmt_elf.c to use the previously added
copy_siginfo_to_external32 to handle the compat case.
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
---
fs/binfmt_elf.c | 5 +----
fs/compat_binfmt_elf.c | 2 +-
include/linux/signal.h | 8 ++++++++
3 files changed, 10 insertions(+), 5 deletions(-)
diff --git a/fs/binfmt_elf.c b/fs/binfmt_elf.c
index 13f25e241ac4..a1f57e20c3cf 100644
--- a/fs/binfmt_elf.c
+++ b/fs/binfmt_elf.c
@@ -1556,10 +1556,7 @@ static void fill_auxv_note(struct memelfnote *note, struct mm_struct *mm)
static void fill_siginfo_note(struct memelfnote *note, user_siginfo_t *csigdata,
const kernel_siginfo_t *siginfo)
{
- mm_segment_t old_fs = get_fs();
- set_fs(KERNEL_DS);
- copy_siginfo_to_user((user_siginfo_t __user *) csigdata, siginfo);
- set_fs(old_fs);
+ copy_siginfo_to_external(csigdata, siginfo);
fill_note(note, "CORE", NT_SIGINFO, sizeof(*csigdata), csigdata);
}
diff --git a/fs/compat_binfmt_elf.c b/fs/compat_binfmt_elf.c
index aaad4ca1217e..fa0e24e1b726 100644
--- a/fs/compat_binfmt_elf.c
+++ b/fs/compat_binfmt_elf.c
@@ -39,7 +39,7 @@
*/
#define user_long_t compat_long_t
#define user_siginfo_t compat_siginfo_t
-#define copy_siginfo_to_user copy_siginfo_to_user32
+#define copy_siginfo_to_external copy_siginfo_to_external32
/*
* The machine-dependent core note format types are defined in elfcore-compat.h,
diff --git a/include/linux/signal.h b/include/linux/signal.h
index 05bacd2ab135..6bb1a3f0258c 100644
--- a/include/linux/signal.h
+++ b/include/linux/signal.h
@@ -24,6 +24,14 @@ static inline void clear_siginfo(kernel_siginfo_t *info)
#define SI_EXPANSION_SIZE (sizeof(struct siginfo) - sizeof(struct kernel_siginfo))
+static inline void copy_siginfo_to_external(siginfo_t *to,
+ const kernel_siginfo_t *from)
+{
+ memcpy(to, from, sizeof(*from));
+ memset(((char *)to) + sizeof(struct kernel_siginfo), 0,
+ SI_EXPANSION_SIZE);
+}
+
int copy_siginfo_to_user(siginfo_t __user *to, const kernel_siginfo_t *from);
int copy_siginfo_from_user(kernel_siginfo_t *to, const siginfo_t __user *from);
--
2.26.1
^ permalink raw reply related
* remove set_fs calls from the exec and coredump code v3
From: Christoph Hellwig @ 2020-04-21 15:41 UTC (permalink / raw)
To: Andrew Morton, Alexander Viro
Cc: Arnd Bergmann, linux-kernel, Jeremy Kerr, linux-fsdevel,
linuxppc-dev, Eric W . Biederman
Hi all,
this series gets rid of playing with the address limit in the exec and
coredump code. Most of this was fairly trivial, the biggest changes are
those to the spufs coredump code.
Changes since v2:
- don't cleanup the compat siginfo calling conventions, use the patch
variant from Eric with slight coding style fixes instead.
Changes since v1:
- properly spell NUL
- properly handle the compat siginfo case in ELF coredumps
^ permalink raw reply
* [PATCH 2/7] signal: factor copy_siginfo_to_external32 from copy_siginfo_to_user32
From: Christoph Hellwig @ 2020-04-21 15:41 UTC (permalink / raw)
To: Andrew Morton, Alexander Viro
Cc: Arnd Bergmann, linux-kernel, Jeremy Kerr, linux-fsdevel,
linuxppc-dev, Eric W . Biederman
In-Reply-To: <20200421154204.252921-1-hch@lst.de>
From: "Eric W. Biederman" <ebiederm@xmission.com>
To remove the use of set_fs in the coredump code there needs to be a
way to convert a kernel siginfo to a userspace compat siginfo.
Call that function copy_siginfo_to_compat and factor it out of
copy_siginfo_to_user32.
The existence of x32 complicates this code. On x32 SIGCHLD uses 64bit
times for utime and stime. As only SIGCHLD is affected and SIGCHLD
never causes a coredump I have avoided handling that case.
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
---
include/linux/compat.h | 2 +
kernel/signal.c | 109 +++++++++++++++++++++++------------------
2 files changed, 64 insertions(+), 47 deletions(-)
diff --git a/include/linux/compat.h b/include/linux/compat.h
index 0480ba4db592..adbfe8f688d9 100644
--- a/include/linux/compat.h
+++ b/include/linux/compat.h
@@ -402,6 +402,8 @@ long compat_get_bitmap(unsigned long *mask, const compat_ulong_t __user *umask,
unsigned long bitmap_size);
long compat_put_bitmap(compat_ulong_t __user *umask, unsigned long *mask,
unsigned long bitmap_size);
+void copy_siginfo_to_external32(struct compat_siginfo *to,
+ const struct kernel_siginfo *from);
int copy_siginfo_from_user32(kernel_siginfo_t *to, const struct compat_siginfo __user *from);
int copy_siginfo_to_user32(struct compat_siginfo __user *to, const kernel_siginfo_t *from);
int get_compat_sigevent(struct sigevent *event,
diff --git a/kernel/signal.c b/kernel/signal.c
index 713104884414..d8eb30914771 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -3231,94 +3231,109 @@ int copy_siginfo_from_user(kernel_siginfo_t *to, const siginfo_t __user *from)
}
#ifdef CONFIG_COMPAT
-int copy_siginfo_to_user32(struct compat_siginfo __user *to,
- const struct kernel_siginfo *from)
-#if defined(CONFIG_X86_X32_ABI) || defined(CONFIG_IA32_EMULATION)
-{
- return __copy_siginfo_to_user32(to, from, in_x32_syscall());
-}
-int __copy_siginfo_to_user32(struct compat_siginfo __user *to,
- const struct kernel_siginfo *from, bool x32_ABI)
-#endif
+void copy_siginfo_to_external32(struct compat_siginfo *to,
+ const struct kernel_siginfo *from)
{
- struct compat_siginfo new;
- memset(&new, 0, sizeof(new));
+ /*
+ * This function does not work properly for SIGCHLD on x32,
+ * but it does not need to as SIGCHLD never causes a coredump.
+ */
+ memset(to, 0, sizeof(*to));
- new.si_signo = from->si_signo;
- new.si_errno = from->si_errno;
- new.si_code = from->si_code;
+ to->si_signo = from->si_signo;
+ to->si_errno = from->si_errno;
+ to->si_code = from->si_code;
switch(siginfo_layout(from->si_signo, from->si_code)) {
case SIL_KILL:
- new.si_pid = from->si_pid;
- new.si_uid = from->si_uid;
+ to->si_pid = from->si_pid;
+ to->si_uid = from->si_uid;
break;
case SIL_TIMER:
- new.si_tid = from->si_tid;
- new.si_overrun = from->si_overrun;
- new.si_int = from->si_int;
+ to->si_tid = from->si_tid;
+ to->si_overrun = from->si_overrun;
+ to->si_int = from->si_int;
break;
case SIL_POLL:
- new.si_band = from->si_band;
- new.si_fd = from->si_fd;
+ to->si_band = from->si_band;
+ to->si_fd = from->si_fd;
break;
case SIL_FAULT:
- new.si_addr = ptr_to_compat(from->si_addr);
+ to->si_addr = ptr_to_compat(from->si_addr);
#ifdef __ARCH_SI_TRAPNO
- new.si_trapno = from->si_trapno;
+ to->si_trapno = from->si_trapno;
#endif
break;
case SIL_FAULT_MCEERR:
- new.si_addr = ptr_to_compat(from->si_addr);
+ to->si_addr = ptr_to_compat(from->si_addr);
#ifdef __ARCH_SI_TRAPNO
- new.si_trapno = from->si_trapno;
+ to->si_trapno = from->si_trapno;
#endif
- new.si_addr_lsb = from->si_addr_lsb;
+ to->si_addr_lsb = from->si_addr_lsb;
break;
case SIL_FAULT_BNDERR:
- new.si_addr = ptr_to_compat(from->si_addr);
+ to->si_addr = ptr_to_compat(from->si_addr);
#ifdef __ARCH_SI_TRAPNO
- new.si_trapno = from->si_trapno;
+ to->si_trapno = from->si_trapno;
#endif
- new.si_lower = ptr_to_compat(from->si_lower);
- new.si_upper = ptr_to_compat(from->si_upper);
+ to->si_lower = ptr_to_compat(from->si_lower);
+ to->si_upper = ptr_to_compat(from->si_upper);
break;
case SIL_FAULT_PKUERR:
- new.si_addr = ptr_to_compat(from->si_addr);
+ to->si_addr = ptr_to_compat(from->si_addr);
#ifdef __ARCH_SI_TRAPNO
- new.si_trapno = from->si_trapno;
+ to->si_trapno = from->si_trapno;
#endif
- new.si_pkey = from->si_pkey;
+ to->si_pkey = from->si_pkey;
break;
case SIL_CHLD:
- new.si_pid = from->si_pid;
- new.si_uid = from->si_uid;
- new.si_status = from->si_status;
+ to->si_pid = from->si_pid;
+ to->si_uid = from->si_uid;
+ to->si_status = from->si_status;
+ to->si_utime = from->si_utime;
+ to->si_stime = from->si_stime;
#ifdef CONFIG_X86_X32_ABI
if (x32_ABI) {
- new._sifields._sigchld_x32._utime = from->si_utime;
- new._sifields._sigchld_x32._stime = from->si_stime;
+ to->_sifields._sigchld_x32._utime = from->si_utime;
+ to->_sifields._sigchld_x32._stime = from->si_stime;
} else
#endif
{
- new.si_utime = from->si_utime;
- new.si_stime = from->si_stime;
}
break;
case SIL_RT:
- new.si_pid = from->si_pid;
- new.si_uid = from->si_uid;
- new.si_int = from->si_int;
+ to->si_pid = from->si_pid;
+ to->si_uid = from->si_uid;
+ to->si_int = from->si_int;
break;
case SIL_SYS:
- new.si_call_addr = ptr_to_compat(from->si_call_addr);
- new.si_syscall = from->si_syscall;
- new.si_arch = from->si_arch;
+ to->si_call_addr = ptr_to_compat(from->si_call_addr);
+ to->si_syscall = from->si_syscall;
+ to->si_arch = from->si_arch;
break;
}
+}
+
+int copy_siginfo_to_user32(struct compat_siginfo __user *to,
+ const struct kernel_siginfo *from)
+#if defined(CONFIG_X86_X32_ABI) || defined(CONFIG_IA32_EMULATION)
+{
+ return __copy_siginfo_to_user32(to, from, in_x32_syscall());
+}
+int __copy_siginfo_to_user32(struct compat_siginfo __user *to,
+ const struct kernel_siginfo *from, bool x32_ABI)
+#endif
+{
+ struct compat_siginfo new;
+ copy_siginfo_to_external32(&new, from);
+#ifdef CONFIG_X86_X32_ABI
+ if (x32_ABI && from->si_signo == SIGCHLD) {
+ new._sifields._sigchld_x32._utime = from->si_utime;
+ new._sifields._sigchld_x32._stime = from->si_stime;
+ }
+#endif
if (copy_to_user(to, &new, sizeof(struct compat_siginfo)))
return -EFAULT;
-
return 0;
}
--
2.26.1
^ permalink raw reply related
* [PATCH 1/7] powerpc/spufs: simplify spufs core dumping
From: Christoph Hellwig @ 2020-04-21 15:41 UTC (permalink / raw)
To: Andrew Morton, Alexander Viro
Cc: Arnd Bergmann, linux-kernel, Jeremy Kerr, linux-fsdevel,
linuxppc-dev, Eric W . Biederman
In-Reply-To: <20200421154204.252921-1-hch@lst.de>
Replace the coredump ->read method with a ->dump method that must call
dump_emit itself. That way we avoid a buffer allocation an messing with
set_fs() to call into code that is intended to deal with user buffers.
For the ->get case we can now use a small on-stack buffer and avoid
memory allocations as well.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Jeremy Kerr <jk@ozlabs.org>
---
arch/powerpc/platforms/cell/spufs/coredump.c | 87 ++----
arch/powerpc/platforms/cell/spufs/file.c | 273 ++++++++++---------
arch/powerpc/platforms/cell/spufs/spufs.h | 3 +-
3 files changed, 170 insertions(+), 193 deletions(-)
diff --git a/arch/powerpc/platforms/cell/spufs/coredump.c b/arch/powerpc/platforms/cell/spufs/coredump.c
index 8b3296b62f65..3b75e8f60609 100644
--- a/arch/powerpc/platforms/cell/spufs/coredump.c
+++ b/arch/powerpc/platforms/cell/spufs/coredump.c
@@ -21,22 +21,6 @@
#include "spufs.h"
-static ssize_t do_coredump_read(int num, struct spu_context *ctx, void *buffer,
- size_t size, loff_t *off)
-{
- u64 data;
- int ret;
-
- if (spufs_coredump_read[num].read)
- return spufs_coredump_read[num].read(ctx, buffer, size, off);
-
- data = spufs_coredump_read[num].get(ctx);
- ret = snprintf(buffer, size, "0x%.16llx", data);
- if (ret >= size)
- return size;
- return ++ret; /* count trailing NULL */
-}
-
static int spufs_ctx_note_size(struct spu_context *ctx, int dfd)
{
int i, sz, total = 0;
@@ -118,58 +102,43 @@ int spufs_coredump_extra_notes_size(void)
static int spufs_arch_write_note(struct spu_context *ctx, int i,
struct coredump_params *cprm, int dfd)
{
- loff_t pos = 0;
- int sz, rc, total = 0;
- const int bufsz = PAGE_SIZE;
- char *name;
- char fullname[80], *buf;
+ size_t sz = spufs_coredump_read[i].size;
+ char fullname[80];
struct elf_note en;
- size_t skip;
-
- buf = (void *)get_zeroed_page(GFP_KERNEL);
- if (!buf)
- return -ENOMEM;
+ size_t ret;
- name = spufs_coredump_read[i].name;
- sz = spufs_coredump_read[i].size;
-
- sprintf(fullname, "SPU/%d/%s", dfd, name);
+ sprintf(fullname, "SPU/%d/%s", dfd, spufs_coredump_read[i].name);
en.n_namesz = strlen(fullname) + 1;
en.n_descsz = sz;
en.n_type = NT_SPU;
if (!dump_emit(cprm, &en, sizeof(en)))
- goto Eio;
-
+ return -EIO;
if (!dump_emit(cprm, fullname, en.n_namesz))
- goto Eio;
-
+ return -EIO;
if (!dump_align(cprm, 4))
- goto Eio;
-
- do {
- rc = do_coredump_read(i, ctx, buf, bufsz, &pos);
- if (rc > 0) {
- if (!dump_emit(cprm, buf, rc))
- goto Eio;
- total += rc;
- }
- } while (rc == bufsz && total < sz);
-
- if (rc < 0)
- goto out;
-
- skip = roundup(cprm->pos - total + sz, 4) - cprm->pos;
- if (!dump_skip(cprm, skip))
- goto Eio;
-
- rc = 0;
-out:
- free_page((unsigned long)buf);
- return rc;
-Eio:
- free_page((unsigned long)buf);
- return -EIO;
+ return -EIO;
+
+ if (spufs_coredump_read[i].dump) {
+ ret = spufs_coredump_read[i].dump(ctx, cprm);
+ if (ret < 0)
+ return ret;
+ } else {
+ char buf[32];
+
+ ret = snprintf(buf, sizeof(buf), "0x%.16llx",
+ spufs_coredump_read[i].get(ctx));
+ if (ret >= sizeof(buf))
+ return sizeof(buf);
+
+ /* count trailing the NULL: */
+ if (!dump_emit(cprm, buf, ret + 1))
+ return -EIO;
+ }
+
+ if (!dump_skip(cprm, roundup(cprm->pos - ret + sz, 4) - cprm->pos))
+ return -EIO;
+ return 0;
}
int spufs_coredump_extra_notes_write(struct coredump_params *cprm)
diff --git a/arch/powerpc/platforms/cell/spufs/file.c b/arch/powerpc/platforms/cell/spufs/file.c
index c0f950a3f4e1..0f8c3d692af0 100644
--- a/arch/powerpc/platforms/cell/spufs/file.c
+++ b/arch/powerpc/platforms/cell/spufs/file.c
@@ -9,6 +9,7 @@
#undef DEBUG
+#include <linux/coredump.h>
#include <linux/fs.h>
#include <linux/ioctl.h>
#include <linux/export.h>
@@ -129,6 +130,14 @@ static ssize_t spufs_attr_write(struct file *file, const char __user *buf,
return ret;
}
+static ssize_t spufs_dump_emit(struct coredump_params *cprm, void *buf,
+ size_t size)
+{
+ if (!dump_emit(cprm, buf, size))
+ return -EIO;
+ return size;
+}
+
#define DEFINE_SPUFS_SIMPLE_ATTRIBUTE(__fops, __get, __set, __fmt) \
static int __fops ## _open(struct inode *inode, struct file *file) \
{ \
@@ -172,12 +181,9 @@ spufs_mem_release(struct inode *inode, struct file *file)
}
static ssize_t
-__spufs_mem_read(struct spu_context *ctx, char __user *buffer,
- size_t size, loff_t *pos)
+spufs_mem_dump(struct spu_context *ctx, struct coredump_params *cprm)
{
- char *local_store = ctx->ops->get_ls(ctx);
- return simple_read_from_buffer(buffer, size, pos, local_store,
- LS_SIZE);
+ return spufs_dump_emit(cprm, ctx->ops->get_ls(ctx), LS_SIZE);
}
static ssize_t
@@ -190,7 +196,8 @@ spufs_mem_read(struct file *file, char __user *buffer,
ret = spu_acquire(ctx);
if (ret)
return ret;
- ret = __spufs_mem_read(ctx, buffer, size, pos);
+ ret = simple_read_from_buffer(buffer, size, pos, ctx->ops->get_ls(ctx),
+ LS_SIZE);
spu_release(ctx);
return ret;
@@ -459,12 +466,10 @@ spufs_regs_open(struct inode *inode, struct file *file)
}
static ssize_t
-__spufs_regs_read(struct spu_context *ctx, char __user *buffer,
- size_t size, loff_t *pos)
+spufs_regs_dump(struct spu_context *ctx, struct coredump_params *cprm)
{
- struct spu_lscsa *lscsa = ctx->csa.lscsa;
- return simple_read_from_buffer(buffer, size, pos,
- lscsa->gprs, sizeof lscsa->gprs);
+ return spufs_dump_emit(cprm, ctx->csa.lscsa->gprs,
+ sizeof(ctx->csa.lscsa->gprs));
}
static ssize_t
@@ -482,7 +487,8 @@ spufs_regs_read(struct file *file, char __user *buffer,
ret = spu_acquire_saved(ctx);
if (ret)
return ret;
- ret = __spufs_regs_read(ctx, buffer, size, pos);
+ ret = simple_read_from_buffer(buffer, size, pos, ctx->csa.lscsa->gprs,
+ sizeof(ctx->csa.lscsa->gprs));
spu_release_saved(ctx);
return ret;
}
@@ -517,12 +523,10 @@ static const struct file_operations spufs_regs_fops = {
};
static ssize_t
-__spufs_fpcr_read(struct spu_context *ctx, char __user * buffer,
- size_t size, loff_t * pos)
+spufs_fpcr_dump(struct spu_context *ctx, struct coredump_params *cprm)
{
- struct spu_lscsa *lscsa = ctx->csa.lscsa;
- return simple_read_from_buffer(buffer, size, pos,
- &lscsa->fpcr, sizeof(lscsa->fpcr));
+ return spufs_dump_emit(cprm, &ctx->csa.lscsa->fpcr,
+ sizeof(ctx->csa.lscsa->fpcr));
}
static ssize_t
@@ -535,7 +539,8 @@ spufs_fpcr_read(struct file *file, char __user * buffer,
ret = spu_acquire_saved(ctx);
if (ret)
return ret;
- ret = __spufs_fpcr_read(ctx, buffer, size, pos);
+ ret = simple_read_from_buffer(buffer, size, pos, &ctx->csa.lscsa->fpcr,
+ sizeof(ctx->csa.lscsa->fpcr));
spu_release_saved(ctx);
return ret;
}
@@ -967,28 +972,26 @@ spufs_signal1_release(struct inode *inode, struct file *file)
return 0;
}
-static ssize_t __spufs_signal1_read(struct spu_context *ctx, char __user *buf,
- size_t len, loff_t *pos)
+static ssize_t spufs_signal1_dump(struct spu_context *ctx,
+ struct coredump_params *cprm)
{
- int ret = 0;
- u32 data;
+ if (!ctx->csa.spu_chnlcnt_RW[3])
+ return 0;
+ return spufs_dump_emit(cprm, &ctx->csa.spu_chnldata_RW[3],
+ sizeof(ctx->csa.spu_chnldata_RW[3]));
+}
- if (len < 4)
+static ssize_t __spufs_signal1_read(struct spu_context *ctx, char __user *buf,
+ size_t len)
+{
+ if (len < sizeof(ctx->csa.spu_chnldata_RW[3]))
return -EINVAL;
-
- if (ctx->csa.spu_chnlcnt_RW[3]) {
- data = ctx->csa.spu_chnldata_RW[3];
- ret = 4;
- }
-
- if (!ret)
- goto out;
-
- if (copy_to_user(buf, &data, 4))
+ if (!ctx->csa.spu_chnlcnt_RW[3])
+ return 0;
+ if (copy_to_user(buf, &ctx->csa.spu_chnldata_RW[3],
+ sizeof(ctx->csa.spu_chnldata_RW[3])))
return -EFAULT;
-
-out:
- return ret;
+ return sizeof(ctx->csa.spu_chnldata_RW[3]);
}
static ssize_t spufs_signal1_read(struct file *file, char __user *buf,
@@ -1000,7 +1003,7 @@ static ssize_t spufs_signal1_read(struct file *file, char __user *buf,
ret = spu_acquire_saved(ctx);
if (ret)
return ret;
- ret = __spufs_signal1_read(ctx, buf, len, pos);
+ ret = __spufs_signal1_read(ctx, buf, len);
spu_release_saved(ctx);
return ret;
@@ -1104,28 +1107,26 @@ spufs_signal2_release(struct inode *inode, struct file *file)
return 0;
}
-static ssize_t __spufs_signal2_read(struct spu_context *ctx, char __user *buf,
- size_t len, loff_t *pos)
+static ssize_t spufs_signal2_dump(struct spu_context *ctx,
+ struct coredump_params *cprm)
{
- int ret = 0;
- u32 data;
+ if (!ctx->csa.spu_chnlcnt_RW[4])
+ return 0;
+ return spufs_dump_emit(cprm, &ctx->csa.spu_chnldata_RW[4],
+ sizeof(ctx->csa.spu_chnldata_RW[4]));
+}
- if (len < 4)
+static ssize_t __spufs_signal2_read(struct spu_context *ctx, char __user *buf,
+ size_t len)
+{
+ if (len < sizeof(ctx->csa.spu_chnldata_RW[4]))
return -EINVAL;
-
- if (ctx->csa.spu_chnlcnt_RW[4]) {
- data = ctx->csa.spu_chnldata_RW[4];
- ret = 4;
- }
-
- if (!ret)
- goto out;
-
- if (copy_to_user(buf, &data, 4))
+ if (!ctx->csa.spu_chnlcnt_RW[4])
+ return 0;
+ if (copy_to_user(buf, &ctx->csa.spu_chnldata_RW[4],
+ sizeof(ctx->csa.spu_chnldata_RW[4])))
return -EFAULT;
-
-out:
- return ret;
+ return sizeof(ctx->csa.spu_chnldata_RW[4]);
}
static ssize_t spufs_signal2_read(struct file *file, char __user *buf,
@@ -1137,7 +1138,7 @@ static ssize_t spufs_signal2_read(struct file *file, char __user *buf,
ret = spu_acquire_saved(ctx);
if (ret)
return ret;
- ret = __spufs_signal2_read(ctx, buf, len, pos);
+ ret = __spufs_signal2_read(ctx, buf, len);
spu_release_saved(ctx);
return ret;
@@ -1961,18 +1962,13 @@ static const struct file_operations spufs_caps_fops = {
.release = single_release,
};
-static ssize_t __spufs_mbox_info_read(struct spu_context *ctx,
- char __user *buf, size_t len, loff_t *pos)
+static ssize_t spufs_mbox_info_dump(struct spu_context *ctx,
+ struct coredump_params *cprm)
{
- u32 data;
-
- /* EOF if there's no entry in the mbox */
if (!(ctx->csa.prob.mb_stat_R & 0x0000ff))
return 0;
-
- data = ctx->csa.prob.pu_mb_R;
-
- return simple_read_from_buffer(buf, len, pos, &data, sizeof data);
+ return spufs_dump_emit(cprm, &ctx->csa.prob.pu_mb_R,
+ sizeof(ctx->csa.prob.pu_mb_R));
}
static ssize_t spufs_mbox_info_read(struct file *file, char __user *buf,
@@ -1988,7 +1984,12 @@ static ssize_t spufs_mbox_info_read(struct file *file, char __user *buf,
if (ret)
return ret;
spin_lock(&ctx->csa.register_lock);
- ret = __spufs_mbox_info_read(ctx, buf, len, pos);
+ /* EOF if there's no entry in the mbox */
+ if (ctx->csa.prob.mb_stat_R & 0x0000ff) {
+ ret = simple_read_from_buffer(buf, len, pos,
+ &ctx->csa.prob.pu_mb_R,
+ sizeof(ctx->csa.prob.pu_mb_R));
+ }
spin_unlock(&ctx->csa.register_lock);
spu_release_saved(ctx);
@@ -2001,18 +2002,13 @@ static const struct file_operations spufs_mbox_info_fops = {
.llseek = generic_file_llseek,
};
-static ssize_t __spufs_ibox_info_read(struct spu_context *ctx,
- char __user *buf, size_t len, loff_t *pos)
+static ssize_t spufs_ibox_info_dump(struct spu_context *ctx,
+ struct coredump_params *cprm)
{
- u32 data;
-
- /* EOF if there's no entry in the ibox */
if (!(ctx->csa.prob.mb_stat_R & 0xff0000))
return 0;
-
- data = ctx->csa.priv2.puint_mb_R;
-
- return simple_read_from_buffer(buf, len, pos, &data, sizeof data);
+ return spufs_dump_emit(cprm, &ctx->csa.priv2.puint_mb_R,
+ sizeof(ctx->csa.priv2.puint_mb_R));
}
static ssize_t spufs_ibox_info_read(struct file *file, char __user *buf,
@@ -2028,7 +2024,12 @@ static ssize_t spufs_ibox_info_read(struct file *file, char __user *buf,
if (ret)
return ret;
spin_lock(&ctx->csa.register_lock);
- ret = __spufs_ibox_info_read(ctx, buf, len, pos);
+ /* EOF if there's no entry in the ibox */
+ if (ctx->csa.prob.mb_stat_R & 0xff0000) {
+ ret = simple_read_from_buffer(buf, len, pos,
+ &ctx->csa.priv2.puint_mb_R,
+ sizeof(ctx->csa.priv2.puint_mb_R));
+ }
spin_unlock(&ctx->csa.register_lock);
spu_release_saved(ctx);
@@ -2041,21 +2042,16 @@ static const struct file_operations spufs_ibox_info_fops = {
.llseek = generic_file_llseek,
};
-static ssize_t __spufs_wbox_info_read(struct spu_context *ctx,
- char __user *buf, size_t len, loff_t *pos)
+static size_t spufs_wbox_info_cnt(struct spu_context *ctx)
{
- int i, cnt;
- u32 data[4];
- u32 wbox_stat;
-
- wbox_stat = ctx->csa.prob.mb_stat_R;
- cnt = 4 - ((wbox_stat & 0x00ff00) >> 8);
- for (i = 0; i < cnt; i++) {
- data[i] = ctx->csa.spu_mailbox_data[i];
- }
+ return (4 - ((ctx->csa.prob.mb_stat_R & 0x00ff00) >> 8)) * sizeof(u32);
+}
- return simple_read_from_buffer(buf, len, pos, &data,
- cnt * sizeof(u32));
+static ssize_t spufs_wbox_info_dump(struct spu_context *ctx,
+ struct coredump_params *cprm)
+{
+ return spufs_dump_emit(cprm, &ctx->csa.spu_mailbox_data,
+ spufs_wbox_info_cnt(ctx));
}
static ssize_t spufs_wbox_info_read(struct file *file, char __user *buf,
@@ -2071,7 +2067,8 @@ static ssize_t spufs_wbox_info_read(struct file *file, char __user *buf,
if (ret)
return ret;
spin_lock(&ctx->csa.register_lock);
- ret = __spufs_wbox_info_read(ctx, buf, len, pos);
+ ret = simple_read_from_buffer(buf, len, pos, &ctx->csa.spu_mailbox_data,
+ spufs_wbox_info_cnt(ctx));
spin_unlock(&ctx->csa.register_lock);
spu_release_saved(ctx);
@@ -2084,36 +2081,42 @@ static const struct file_operations spufs_wbox_info_fops = {
.llseek = generic_file_llseek,
};
-static ssize_t __spufs_dma_info_read(struct spu_context *ctx,
- char __user *buf, size_t len, loff_t *pos)
+static void __spufs_dma_info_read(struct spu_context *ctx,
+ struct spu_dma_info *info)
{
- struct spu_dma_info info;
- struct mfc_cq_sr *qp, *spuqp;
int i;
- info.dma_info_type = ctx->csa.priv2.spu_tag_status_query_RW;
- info.dma_info_mask = ctx->csa.lscsa->tag_mask.slot[0];
- info.dma_info_status = ctx->csa.spu_chnldata_RW[24];
- info.dma_info_stall_and_notify = ctx->csa.spu_chnldata_RW[25];
- info.dma_info_atomic_command_status = ctx->csa.spu_chnldata_RW[27];
+ info->dma_info_type = ctx->csa.priv2.spu_tag_status_query_RW;
+ info->dma_info_mask = ctx->csa.lscsa->tag_mask.slot[0];
+ info->dma_info_status = ctx->csa.spu_chnldata_RW[24];
+ info->dma_info_stall_and_notify = ctx->csa.spu_chnldata_RW[25];
+ info->dma_info_atomic_command_status = ctx->csa.spu_chnldata_RW[27];
+
for (i = 0; i < 16; i++) {
- qp = &info.dma_info_command_data[i];
- spuqp = &ctx->csa.priv2.spuq[i];
+ struct mfc_cq_sr *qp = &info->dma_info_command_data[i];
+ struct mfc_cq_sr *spuqp = &ctx->csa.priv2.spuq[i];
qp->mfc_cq_data0_RW = spuqp->mfc_cq_data0_RW;
qp->mfc_cq_data1_RW = spuqp->mfc_cq_data1_RW;
qp->mfc_cq_data2_RW = spuqp->mfc_cq_data2_RW;
qp->mfc_cq_data3_RW = spuqp->mfc_cq_data3_RW;
}
+}
+
+static ssize_t spufs_dma_info_dump(struct spu_context *ctx,
+ struct coredump_params *cprm)
+{
+ struct spu_dma_info info;
- return simple_read_from_buffer(buf, len, pos, &info,
- sizeof info);
+ __spufs_dma_info_read(ctx, &info);
+ return spufs_dump_emit(cprm, &info, sizeof(info));
}
static ssize_t spufs_dma_info_read(struct file *file, char __user *buf,
size_t len, loff_t *pos)
{
struct spu_context *ctx = file->private_data;
+ struct spu_dma_info info;
int ret;
if (!access_ok(buf, len))
@@ -2123,7 +2126,8 @@ static ssize_t spufs_dma_info_read(struct file *file, char __user *buf,
if (ret)
return ret;
spin_lock(&ctx->csa.register_lock);
- ret = __spufs_dma_info_read(ctx, buf, len, pos);
+ __spufs_dma_info_read(ctx, &info);
+ ret = simple_read_from_buffer(buf, len, pos, &info, sizeof(info));
spin_unlock(&ctx->csa.register_lock);
spu_release_saved(ctx);
@@ -2136,48 +2140,53 @@ static const struct file_operations spufs_dma_info_fops = {
.llseek = no_llseek,
};
-static ssize_t __spufs_proxydma_info_read(struct spu_context *ctx,
- char __user *buf, size_t len, loff_t *pos)
+static void __spufs_proxydma_info_read(struct spu_context *ctx,
+ struct spu_proxydma_info *info)
{
- struct spu_proxydma_info info;
- struct mfc_cq_sr *qp, *puqp;
- int ret = sizeof info;
int i;
- if (len < ret)
- return -EINVAL;
-
- if (!access_ok(buf, len))
- return -EFAULT;
+ info->proxydma_info_type = ctx->csa.prob.dma_querytype_RW;
+ info->proxydma_info_mask = ctx->csa.prob.dma_querymask_RW;
+ info->proxydma_info_status = ctx->csa.prob.dma_tagstatus_R;
- info.proxydma_info_type = ctx->csa.prob.dma_querytype_RW;
- info.proxydma_info_mask = ctx->csa.prob.dma_querymask_RW;
- info.proxydma_info_status = ctx->csa.prob.dma_tagstatus_R;
for (i = 0; i < 8; i++) {
- qp = &info.proxydma_info_command_data[i];
- puqp = &ctx->csa.priv2.puq[i];
+ struct mfc_cq_sr *qp = &info->proxydma_info_command_data[i];
+ struct mfc_cq_sr *puqp = &ctx->csa.priv2.puq[i];
qp->mfc_cq_data0_RW = puqp->mfc_cq_data0_RW;
qp->mfc_cq_data1_RW = puqp->mfc_cq_data1_RW;
qp->mfc_cq_data2_RW = puqp->mfc_cq_data2_RW;
qp->mfc_cq_data3_RW = puqp->mfc_cq_data3_RW;
}
+}
+
+static ssize_t spufs_proxydma_info_dump(struct spu_context *ctx,
+ struct coredump_params *cprm)
+{
+ struct spu_proxydma_info info;
- return simple_read_from_buffer(buf, len, pos, &info,
- sizeof info);
+ __spufs_proxydma_info_read(ctx, &info);
+ return spufs_dump_emit(cprm, &info, sizeof(info));
}
static ssize_t spufs_proxydma_info_read(struct file *file, char __user *buf,
size_t len, loff_t *pos)
{
struct spu_context *ctx = file->private_data;
+ struct spu_proxydma_info info;
int ret;
+ if (len < sizeof(info))
+ return -EINVAL;
+ if (!access_ok(buf, len))
+ return -EFAULT;
+
ret = spu_acquire_saved(ctx);
if (ret)
return ret;
spin_lock(&ctx->csa.register_lock);
- ret = __spufs_proxydma_info_read(ctx, buf, len, pos);
+ __spufs_proxydma_info_read(ctx, &info);
+ ret = simple_read_from_buffer(buf, len, pos, &info, sizeof(info));
spin_unlock(&ctx->csa.register_lock);
spu_release_saved(ctx);
@@ -2625,23 +2634,23 @@ const struct spufs_tree_descr spufs_dir_debug_contents[] = {
};
const struct spufs_coredump_reader spufs_coredump_read[] = {
- { "regs", __spufs_regs_read, NULL, sizeof(struct spu_reg128[128])},
- { "fpcr", __spufs_fpcr_read, NULL, sizeof(struct spu_reg128) },
+ { "regs", spufs_regs_dump, NULL, sizeof(struct spu_reg128[128])},
+ { "fpcr", spufs_fpcr_dump, NULL, sizeof(struct spu_reg128) },
{ "lslr", NULL, spufs_lslr_get, 19 },
{ "decr", NULL, spufs_decr_get, 19 },
{ "decr_status", NULL, spufs_decr_status_get, 19 },
- { "mem", __spufs_mem_read, NULL, LS_SIZE, },
- { "signal1", __spufs_signal1_read, NULL, sizeof(u32) },
+ { "mem", spufs_mem_dump, NULL, LS_SIZE, },
+ { "signal1", spufs_signal1_dump, NULL, sizeof(u32) },
{ "signal1_type", NULL, spufs_signal1_type_get, 19 },
- { "signal2", __spufs_signal2_read, NULL, sizeof(u32) },
+ { "signal2", spufs_signal2_dump, NULL, sizeof(u32) },
{ "signal2_type", NULL, spufs_signal2_type_get, 19 },
{ "event_mask", NULL, spufs_event_mask_get, 19 },
{ "event_status", NULL, spufs_event_status_get, 19 },
- { "mbox_info", __spufs_mbox_info_read, NULL, sizeof(u32) },
- { "ibox_info", __spufs_ibox_info_read, NULL, sizeof(u32) },
- { "wbox_info", __spufs_wbox_info_read, NULL, 4 * sizeof(u32)},
- { "dma_info", __spufs_dma_info_read, NULL, sizeof(struct spu_dma_info)},
- { "proxydma_info", __spufs_proxydma_info_read,
+ { "mbox_info", spufs_mbox_info_dump, NULL, sizeof(u32) },
+ { "ibox_info", spufs_ibox_info_dump, NULL, sizeof(u32) },
+ { "wbox_info", spufs_wbox_info_dump, NULL, 4 * sizeof(u32)},
+ { "dma_info", spufs_dma_info_dump, NULL, sizeof(struct spu_dma_info)},
+ { "proxydma_info", spufs_proxydma_info_dump,
NULL, sizeof(struct spu_proxydma_info)},
{ "object-id", NULL, spufs_object_id_get, 19 },
{ "npc", NULL, spufs_npc_get, 19 },
diff --git a/arch/powerpc/platforms/cell/spufs/spufs.h b/arch/powerpc/platforms/cell/spufs/spufs.h
index 413c89afe112..1ba4d884febf 100644
--- a/arch/powerpc/platforms/cell/spufs/spufs.h
+++ b/arch/powerpc/platforms/cell/spufs/spufs.h
@@ -337,8 +337,7 @@ void spufs_dma_callback(struct spu *spu, int type);
extern struct spu_coredump_calls spufs_coredump_calls;
struct spufs_coredump_reader {
char *name;
- ssize_t (*read)(struct spu_context *ctx,
- char __user *buffer, size_t size, loff_t *pos);
+ ssize_t (*dump)(struct spu_context *ctx, struct coredump_params *cprm);
u64 (*get)(struct spu_context *ctx);
size_t size;
};
--
2.26.1
^ permalink raw reply related
* RE: [musl] Powerpc Linux 'scv' system call ABI proposal take 2
From: David Laight @ 2020-04-21 15:31 UTC (permalink / raw)
To: 'Adhemerval Zanella', Rich Felker
Cc: libc-dev@lists.llvm.org, libc-alpha@sourceware.org,
linuxppc-dev@lists.ozlabs.org, 'Nicholas Piggin',
musl@lists.openwall.com
In-Reply-To: <960127e0-57a0-55b4-f309-ae0a675c7756@linaro.org>
From: Adhemerval Zanella
> Sent: 21 April 2020 16:01
>
> On 21/04/2020 11:39, Rich Felker wrote:
> > On Tue, Apr 21, 2020 at 12:28:25PM +0000, David Laight wrote:
> >> From: Nicholas Piggin
> >>> Sent: 20 April 2020 02:10
> >> ...
> >>>>> Yes, but does it really matter to optimize this specific usage case
> >>>>> for size? glibc, for instance, tries to leverage the syscall mechanism
> >>>>> by adding some complex pre-processor asm directives. It optimizes
> >>>>> the syscall code size in most cases. For instance, kill in static case
> >>>>> generates on x86_64:
> >>>>>
> >>>>> 0000000000000000 <__kill>:
> >>>>> 0: b8 3e 00 00 00 mov $0x3e,%eax
> >>>>> 5: 0f 05 syscall
> >>>>> 7: 48 3d 01 f0 ff ff cmp $0xfffffffffffff001,%rax
> >>>>> d: 0f 83 00 00 00 00 jae 13 <__kill+0x13>
> >>
> >> Hmmm... that cmp + jae is unnecessary here.
> >
> > It's not.. Rather the objdump was just mistakenly done without -r so
> > it looks like a nop jump rather than a conditional tail call to the
> > function that sets errno.
> >
>
> Indeed, the output with -r is:
>
> 0000000000000000 <__kill>:
> 0: b8 3e 00 00 00 mov $0x3e,%eax
> 5: 0f 05 syscall
> 7: 48 3d 01 f0 ff ff cmp $0xfffffffffffff001,%rax
> d: 0f 83 00 00 00 00 jae 13 <__kill+0x13>
> f: R_X86_64_PLT32 __syscall_error-0x4
> 13: c3 retq
Yes, I probably should have remembered it looked like that :-)
...
> >> I also suspect it gets predicted very badly.
> >
> > I doubt that. This is a very standard idiom and the size of the offset
> > (which is necessarily 32-bit because it has a relocation on it) is
> > orthogonal to the condition on the jump.
Yes, it only gets mispredicted as badly as any other conditional jump.
I believe modern intel x86 will randomly predict it taken (regardless
of the direction) and then hit a TLB fault on text.unlikely :-)
> > FWIW a syscall like kill takes global kernel-side locks to be able to
> > address a target process by pid, and the rate of meaningful calls you
> > can make to it is very low (since it's bounded by time for target
> > process to act on the signal). Trying to optimize it for speed is
> > pointless, and even size isn't important locally (although in
> > aggregate, lots of wasted small size can add up to more pages = more
> > TLB entries = ...).
>
> I agree and I would prefer to focus on code simplicity to have a
> platform neutral way to handle error and let the compiler optimize
> it than messy with assembly macros to squeeze this kind of
> micro-optimizations.
syscall entry does get micro-optimised.
Real speed-ups can probably be found by optimising other places.
I've a patch i need to resumbit that should improve the reading
of iov[] from user space.
David
-
Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK
Registration No: 1397386 (Wales)
^ permalink raw reply
* Re: [musl] Powerpc Linux 'scv' system call ABI proposal take 2
From: Adhemerval Zanella @ 2020-04-21 15:00 UTC (permalink / raw)
To: Rich Felker, David Laight
Cc: libc-dev@lists.llvm.org, libc-alpha@sourceware.org,
linuxppc-dev@lists.ozlabs.org, 'Nicholas Piggin',
musl@lists.openwall.com
In-Reply-To: <20200421143941.GJ11469@brightrain.aerifal.cx>
On 21/04/2020 11:39, Rich Felker wrote:
> On Tue, Apr 21, 2020 at 12:28:25PM +0000, David Laight wrote:
>> From: Nicholas Piggin
>>> Sent: 20 April 2020 02:10
>> ...
>>>>> Yes, but does it really matter to optimize this specific usage case
>>>>> for size? glibc, for instance, tries to leverage the syscall mechanism
>>>>> by adding some complex pre-processor asm directives. It optimizes
>>>>> the syscall code size in most cases. For instance, kill in static case
>>>>> generates on x86_64:
>>>>>
>>>>> 0000000000000000 <__kill>:
>>>>> 0: b8 3e 00 00 00 mov $0x3e,%eax
>>>>> 5: 0f 05 syscall
>>>>> 7: 48 3d 01 f0 ff ff cmp $0xfffffffffffff001,%rax
>>>>> d: 0f 83 00 00 00 00 jae 13 <__kill+0x13>
>>
>> Hmmm... that cmp + jae is unnecessary here.
>
> It's not.. Rather the objdump was just mistakenly done without -r so
> it looks like a nop jump rather than a conditional tail call to the
> function that sets errno.
>
Indeed, the output with -r is:
0000000000000000 <__kill>:
0: b8 3e 00 00 00 mov $0x3e,%eax
5: 0f 05 syscall
7: 48 3d 01 f0 ff ff cmp $0xfffffffffffff001,%rax
d: 0f 83 00 00 00 00 jae 13 <__kill+0x13>
f: R_X86_64_PLT32 __syscall_error-0x4
13: c3 retq
And for x86_64 __syscall_error is defined as:
0000000000000000 <__syscall_error>:
0: 48 f7 d8 neg %rax
0000000000000003 <__syscall_error_1>:
3: 64 89 04 25 00 00 00 mov %eax,%fs:0x0
a: 00
7: R_X86_64_TPOFF32 errno
b: 48 83 c8 ff or $0xffffffffffffffff,%rax
f: c3 retq
Different than musl, each architecture defines its own error handling
mechanism (some embedded errno setting in syscall itself, other branches
to a __syscall_error like function as x86_64).
This is due most likely from the glibc long history. One of my long
term plan is to just simplify, get rid of the assembly pre-processor,
implement all syscall in C code, and set error handling mechanism in
a platform neutral way using a tail call (most likely you do on musl).
>> It is also a 32bit offset jump.
>> I also suspect it gets predicted very badly.
>
> I doubt that. This is a very standard idiom and the size of the offset
> (which is necessarily 32-bit because it has a relocation on it) is
> orthogonal to the condition on the jump.
>
> FWIW a syscall like kill takes global kernel-side locks to be able to
> address a target process by pid, and the rate of meaningful calls you
> can make to it is very low (since it's bounded by time for target
> process to act on the signal). Trying to optimize it for speed is
> pointless, and even size isn't important locally (although in
> aggregate, lots of wasted small size can add up to more pages = more
> TLB entries = ...).
I agree and I would prefer to focus on code simplicity to have a
platform neutral way to handle error and let the compiler optimize
it than messy with assembly macros to squeeze this kind of
micro-optimizations.
>
>>>>> 13: c3 retq
>>>>>
>>>>> While on musl:
>>>>>
>>>>> 0000000000000000 <kill>:
>>>>> 0: 48 83 ec 08 sub $0x8,%rsp
>>>>> 4: 48 63 ff movslq %edi,%rdi
>>>>> 7: 48 63 f6 movslq %esi,%rsi
>>>>> a: b8 3e 00 00 00 mov $0x3e,%eax
>>>>> f: 0f 05 syscall
>>>>> 11: 48 89 c7 mov %rax,%rdi
>>>>> 14: e8 00 00 00 00 callq 19 <kill+0x19>
>>>>> 19: 5a pop %rdx
>>>>> 1a: c3 retq
>>>>
>>>> Wow that's some extraordinarily bad codegen going on by gcc... The
>>>> sign-extension is semantically needed and I don't see a good way
>>>> around it (glibc's asm is kinda a hack taking advantage of kernel not
>>>> looking at high bits, I think), but the gratuitous stack adjustment
>>>> and refusal to generate a tail call isn't. I'll see if we can track
>>>> down what's going on and get it fixed.
>>
>> A suitable cast might get rid of the sign extension.
>> Possibly just (unsigned int).
>
> No, it won't. The problem is that there is no representation of the
> fact that the kernel is only going to inspect the low 32 bits (by
> declaring the kernel-side function as taking an int argument). The
> external kill function receives arguments by the ABI, where the upper
> bits of int args can contain junk, and the asm register constraints
> for syscalls use longs (or rather an abstract syscall-arg type). It
> wouldn't even work to have macro magic detect that the expressions
> passed are ints and use hacks to avoid that, since it's perfectly
> valid to pass an int to a syscall that expects a long argument (e.g.
> offset to mmap), in which case it needs to be sign-extended.
>
> The only way to avoid this is encoding somewhere the syscall-specific
> knowledge of what arg size the kernel function expects. That's way too
> much redundant effort and too error-prone for the incredibly miniscule
> size benefit you'd get out of it.
>
> Rich
>
^ permalink raw reply
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