From 2fac9717a05fc4b4824422d2c439c1260807c110 Mon Sep 17 00:00:00 2001 From: Reinette Chatre Date: Fri, 25 Sep 2009 14:24:21 -0700 Subject: [PATCH] iwlwifi: fix debugfs buffer handling We keep track of where to write into a buffer by keeping a count of how much has been written so far. When writing to the buffer we thus take the buffer pointer and adding the count of what has been written so far. Keeping track of what has been written so far is done by incrementing this number every time something is written to the buffer with how much has been written at that time. Currently this number is incremented incorrectly when using the "hex_dump_to_buffer" call to add data to the buffer. Fix this by only adding what has been added to the buffer in that call instead of what has been added since beginning of buffer. Issue was discovered and discussed during testing of https://bugzilla.redhat.com/show_bug.cgi?id=464598 . When a user views any of these files they will see something like: [ 179.355202] ------------[ cut here ]------------ [ 179.355209] WARNING: at ../lib/vsprintf.c:989 vsnprintf+0x5ec/0x5f0() [ 179.355212] Hardware name: VGN-Z540N [ 179.355213] Modules linked in: i915 drm i2c_algo_bit i2c_core ipv6 acpi_cpufreq cpufreq_userspace cpufreq_powersave cpufreq_ondemand cpufreq_conservative cpufreq_stats freq_table container sbs sbshc arc4 ecb iwlagn iwlcore joydev led_class mac80211 af_packet pcmcia psmouse sony_laptop cfg80211 iTCO_wdt iTCO_vendor_support pcspkr serio_raw rfkill intel_agp video output tpm_infineon tpm tpm_bios button battery yenta_socket rsrc_nonstatic pcmcia_core processor ac evdev ext3 jbd mbcache sr_mod sg cdrom sd_mod ahci libata scsi_mod ehci_hcd uhci_hcd usbcore thermal fan thermal_sys [ 179.355262] Pid: 5449, comm: cat Not tainted 2.6.31-wl-54419-ge881071 #62 [ 179.355264] Call Trace: [ 179.355267] [] ? vsnprintf+0x5ec/0x5f0 [ 179.355271] [] warn_slowpath_common+0x78/0xd0 [ 179.355275] [] warn_slowpath_null+0xf/0x20 [ 179.355277] [] vsnprintf+0x5ec/0x5f0 [ 179.355280] [] ? scnprintf+0x5d/0x80 [ 179.355283] [] scnprintf+0x5d/0x80 [ 179.355286] [] ? hex_dump_to_buffer+0x189/0x340 [ 179.355290] [] ? __kmalloc+0x207/0x260 [ 179.355303] [] iwl_dbgfs_nvm_read+0xe8/0x220 [iwlcore] [ 179.355306] [] ? __up_read+0x92/0xb0 [ 179.355310] [] vfs_read+0xc8/0x1a0 [ 179.355313] [] sys_read+0x50/0x90 [ 179.355316] [] system_call_fastpath+0x16/0x1b [ 179.355319] ---[ end trace 2383d0d5e0752ca0 ]--- Signed-off-by: Reinette Chatre Signed-off-by: John W. Linville --- drivers/net/wireless/iwlwifi/iwl-debugfs.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/drivers/net/wireless/iwlwifi/iwl-debugfs.c b/drivers/net/wireless/iwlwifi/iwl-debugfs.c index fb844859a443..8c374bf043d0 100644 --- a/drivers/net/wireless/iwlwifi/iwl-debugfs.c +++ b/drivers/net/wireless/iwlwifi/iwl-debugfs.c @@ -410,7 +410,7 @@ static ssize_t iwl_dbgfs_nvm_read(struct file *file, pos += scnprintf(buf + pos, buf_size - pos, "0x%.4x ", ofs); hex_dump_to_buffer(ptr + ofs, 16 , 16, 2, buf + pos, buf_size - pos, 0); - pos += strlen(buf); + pos += strlen(buf + pos); if (buf_size - pos > 0) buf[pos++] = '\n'; } @@ -909,7 +909,7 @@ static ssize_t iwl_dbgfs_traffic_log_read(struct file *file, "0x%.4x ", ofs); hex_dump_to_buffer(ptr + ofs, 16, 16, 2, buf + pos, bufsz - pos, 0); - pos += strlen(buf); + pos += strlen(buf + pos); if (bufsz - pos > 0) buf[pos++] = '\n'; } @@ -932,7 +932,7 @@ static ssize_t iwl_dbgfs_traffic_log_read(struct file *file, "0x%.4x ", ofs); hex_dump_to_buffer(ptr + ofs, 16, 16, 2, buf + pos, bufsz - pos, 0); - pos += strlen(buf); + pos += strlen(buf + pos); if (bufsz - pos > 0) buf[pos++] = '\n'; }