* Re: [PATCH] ntb_tool: Fix infinite loop bug when writing spad/peer_spad file [not found] <1464381511-18491-1-git-send-email-logang@deltatee.com> @ 2016-05-28 13:09 ` Allen Hubbe 2016-06-04 15:19 ` Jon Mason 0 siblings, 1 reply; 2+ messages in thread From: Allen Hubbe @ 2016-05-28 13:09 UTC (permalink / raw) To: Logan Gunthorpe; +Cc: Jon Mason, Dave Jiang, linux-ntb, linux-kernel On Fri, May 27, 2016 at 4:38 PM, Logan Gunthorpe <logang@deltatee.com> wrote: > If you tried to write two spads in one line, as per the example: > > root@peer# echo '0 0x01010101 1 0x7f7f7f7f' > $DBG_DIR/peer_spad > > then the CPU would freeze in an infinite loop. > > This wasn't immediately obvious but 'pos' was not incrementing the > buffer, so after reading the second pair of values, 'pos' would once > again be 3 and it would re-read the second pair of values ad infinitum. > > Signed-off-by: Logan Gunthorpe <logang@deltatee.com> Good catch. Thanks Logan. Acked-by: Allen Hubbe <Allen.Hubbe@emc.com> > --- > drivers/ntb/test/ntb_tool.c | 9 +++++---- > 1 file changed, 5 insertions(+), 4 deletions(-) > > diff --git a/drivers/ntb/test/ntb_tool.c b/drivers/ntb/test/ntb_tool.c > index 6f5dc6c..209ef7c 100644 > --- a/drivers/ntb/test/ntb_tool.c > +++ b/drivers/ntb/test/ntb_tool.c > @@ -268,7 +268,7 @@ static ssize_t tool_spadfn_write(struct tool_ctx *tc, > { > int spad_idx; > u32 spad_val; > - char *buf; > + char *buf, *buf_ptr; > int pos, n; > ssize_t rc; > > @@ -288,14 +288,15 @@ static ssize_t tool_spadfn_write(struct tool_ctx *tc, > } > > buf[size] = 0; > - > - n = sscanf(buf, "%d %i%n", &spad_idx, &spad_val, &pos); > + buf_ptr = buf; > + n = sscanf(buf_ptr, "%d %i%n", &spad_idx, &spad_val, &pos); > while (n == 2) { > + buf_ptr += pos; > rc = spad_write_fn(tc->ntb, spad_idx, spad_val); > if (rc) > break; > > - n = sscanf(buf + pos, "%d %i%n", &spad_idx, &spad_val, &pos); > + n = sscanf(buf_ptr, "%d %i%n", &spad_idx, &spad_val, &pos); > } > > if (n < 0) > -- > 2.1.4 ^ permalink raw reply [flat|nested] 2+ messages in thread
* Re: [PATCH] ntb_tool: Fix infinite loop bug when writing spad/peer_spad file 2016-05-28 13:09 ` [PATCH] ntb_tool: Fix infinite loop bug when writing spad/peer_spad file Allen Hubbe @ 2016-06-04 15:19 ` Jon Mason 0 siblings, 0 replies; 2+ messages in thread From: Jon Mason @ 2016-06-04 15:19 UTC (permalink / raw) To: Allen Hubbe; +Cc: Logan Gunthorpe, Dave Jiang, linux-ntb, linux-kernel On Sat, May 28, 2016 at 9:09 AM, Allen Hubbe <allenbh@gmail.com> wrote: > On Fri, May 27, 2016 at 4:38 PM, Logan Gunthorpe <logang@deltatee.com> wrote: >> If you tried to write two spads in one line, as per the example: >> >> root@peer# echo '0 0x01010101 1 0x7f7f7f7f' > $DBG_DIR/peer_spad >> >> then the CPU would freeze in an infinite loop. >> >> This wasn't immediately obvious but 'pos' was not incrementing the >> buffer, so after reading the second pair of values, 'pos' would once >> again be 3 and it would re-read the second pair of values ad infinitum. >> >> Signed-off-by: Logan Gunthorpe <logang@deltatee.com> > > Good catch. Thanks Logan. > > Acked-by: Allen Hubbe <Allen.Hubbe@emc.com> Applied to the ntb branch Thanks, Jon >> --- >> drivers/ntb/test/ntb_tool.c | 9 +++++---- >> 1 file changed, 5 insertions(+), 4 deletions(-) >> >> diff --git a/drivers/ntb/test/ntb_tool.c b/drivers/ntb/test/ntb_tool.c >> index 6f5dc6c..209ef7c 100644 >> --- a/drivers/ntb/test/ntb_tool.c >> +++ b/drivers/ntb/test/ntb_tool.c >> @@ -268,7 +268,7 @@ static ssize_t tool_spadfn_write(struct tool_ctx *tc, >> { >> int spad_idx; >> u32 spad_val; >> - char *buf; >> + char *buf, *buf_ptr; >> int pos, n; >> ssize_t rc; >> >> @@ -288,14 +288,15 @@ static ssize_t tool_spadfn_write(struct tool_ctx *tc, >> } >> >> buf[size] = 0; >> - >> - n = sscanf(buf, "%d %i%n", &spad_idx, &spad_val, &pos); >> + buf_ptr = buf; >> + n = sscanf(buf_ptr, "%d %i%n", &spad_idx, &spad_val, &pos); >> while (n == 2) { >> + buf_ptr += pos; >> rc = spad_write_fn(tc->ntb, spad_idx, spad_val); >> if (rc) >> break; >> >> - n = sscanf(buf + pos, "%d %i%n", &spad_idx, &spad_val, &pos); >> + n = sscanf(buf_ptr, "%d %i%n", &spad_idx, &spad_val, &pos); >> } >> >> if (n < 0) >> -- >> 2.1.4 ^ permalink raw reply [flat|nested] 2+ messages in thread
end of thread, other threads:[~2016-06-04 15:19 UTC | newest] Thread overview: 2+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- [not found] <1464381511-18491-1-git-send-email-logang@deltatee.com> 2016-05-28 13:09 ` [PATCH] ntb_tool: Fix infinite loop bug when writing spad/peer_spad file Allen Hubbe 2016-06-04 15:19 ` Jon Mason
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