From 97f5f0cd8cd0a05449cbb77d1e6f02e026875802 Mon Sep 17 00:00:00 2001 From: Dmitry Torokhov Date: Sun, 21 Mar 2010 22:31:26 -0700 Subject: Input: implement SysRq as a separate input handler Instead of keeping SysRq support inside of legacy keyboard driver split it out into a separate input handler (filter). This stops most SysRq input events from leaking into evdev clients (some events, such as first SysRq scancode - not keycode - event, are still leaked into both legacy keyboard and evdev). [martinez.javier@gmail.com: fix compile error when CONFIG_MAGIC_SYSRQ is not defined] Signed-off-by: Dmitry Torokhov --- kernel/sysctl.c | 23 ++++++++++++++++++++++- 1 file changed, 22 insertions(+), 1 deletion(-) (limited to 'kernel/sysctl.c') diff --git a/kernel/sysctl.c b/kernel/sysctl.c index 8686b0f5fc12..ce724a0dd0bb 100644 --- a/kernel/sysctl.c +++ b/kernel/sysctl.c @@ -163,6 +163,27 @@ static int proc_taint(struct ctl_table *table, int write, void __user *buffer, size_t *lenp, loff_t *ppos); #endif +#ifdef CONFIG_MAGIC_SYSRQ +static int __sysrq_enabled; /* Note: sysrq code ises it's own private copy */ + +static int sysrq_sysctl_handler(ctl_table *table, int write, + void __user *buffer, size_t *lenp, + loff_t *ppos) +{ + int error; + + error = proc_dointvec(table, write, buffer, lenp, ppos); + if (error) + return error; + + if (write) + sysrq_toggle_support(__sysrq_enabled); + + return 0; +} + +#endif + static struct ctl_table root_table[]; static struct ctl_table_root sysctl_table_root; static struct ctl_table_header root_table_header = { @@ -567,7 +588,7 @@ static struct ctl_table kern_table[] = { .data = &__sysrq_enabled, .maxlen = sizeof (int), .mode = 0644, - .proc_handler = proc_dointvec, + .proc_handler = sysrq_sysctl_handler, }, #endif #ifdef CONFIG_PROC_SYSCTL -- cgit v1.2.3 From 00b7c3395aec3df43de5bd02a3c5a099ca51169f Mon Sep 17 00:00:00 2001 From: Amerigo Wang Date: Wed, 5 May 2010 00:26:45 +0000 Subject: sysctl: refactor integer handling proc code (Based on Octavian's work, and I modified a lot.) As we are about to add another integer handling proc function a little bit of cleanup is in order: add a few helper functions to improve code readability and decrease code duplication. In the process a bug is also fixed: if the user specifies a number with more then 20 digits it will be interpreted as two integers (e.g. 10000...13 will be interpreted as 100.... and 13). Behavior for EFAULT handling was changed as well. Previous to this patch, when an EFAULT error occurred in the middle of a write operation, although some of the elements were set, that was not acknowledged to the user (by shorting the write and returning the number of bytes accepted). EFAULT is now treated just like any other errors by acknowledging the amount of bytes accepted. Signed-off-by: Octavian Purdila Signed-off-by: WANG Cong Cc: Eric W. Biederman Signed-off-by: David S. Miller --- kernel/sysctl.c | 390 +++++++++++++++++++++++++++++++++----------------------- 1 file changed, 229 insertions(+), 161 deletions(-) (limited to 'kernel/sysctl.c') diff --git a/kernel/sysctl.c b/kernel/sysctl.c index 8686b0f5fc12..4a976208de29 100644 --- a/kernel/sysctl.c +++ b/kernel/sysctl.c @@ -2040,8 +2040,122 @@ int proc_dostring(struct ctl_table *table, int write, buffer, lenp, ppos); } +static size_t proc_skip_spaces(char **buf) +{ + size_t ret; + char *tmp = skip_spaces(*buf); + ret = tmp - *buf; + *buf = tmp; + return ret; +} + +#define TMPBUFLEN 22 +/** + * proc_get_long - reads an ASCII formated integer from a user buffer + * + * @buf - a kernel buffer + * @size - size of the kernel buffer + * @val - this is where the number will be stored + * @neg - set to %TRUE if number is negative + * @perm_tr - a vector which contains the allowed trailers + * @perm_tr_len - size of the perm_tr vector + * @tr - pointer to store the trailer character + * + * In case of success 0 is returned and buf and size are updated with + * the amount of bytes read. If tr is non NULL and a trailing + * character exist (size is non zero after returning from this + * function) tr is updated with the trailing character. + */ +static int proc_get_long(char **buf, size_t *size, + unsigned long *val, bool *neg, + const char *perm_tr, unsigned perm_tr_len, char *tr) +{ + int len; + char *p, tmp[TMPBUFLEN]; + + if (!*size) + return -EINVAL; + + len = *size; + if (len > TMPBUFLEN - 1) + len = TMPBUFLEN - 1; + + memcpy(tmp, *buf, len); + + tmp[len] = 0; + p = tmp; + if (*p == '-' && *size > 1) { + *neg = true; + p++; + } else + *neg = false; + if (!isdigit(*p)) + return -EINVAL; + + *val = simple_strtoul(p, &p, 0); + + len = p - tmp; + + /* We don't know if the next char is whitespace thus we may accept + * invalid integers (e.g. 1234...a) or two integers instead of one + * (e.g. 123...1). So lets not allow such large numbers. */ + if (len == TMPBUFLEN - 1) + return -EINVAL; + + if (len < *size && perm_tr_len && !memchr(perm_tr, *p, perm_tr_len)) + return -EINVAL; -static int do_proc_dointvec_conv(int *negp, unsigned long *lvalp, + if (tr && (len < *size)) + *tr = *p; + + *buf += len; + *size -= len; + + return 0; +} + +/** + * proc_put_long - coverts an integer to a decimal ASCII formated string + * + * @buf - the user buffer + * @size - the size of the user buffer + * @val - the integer to be converted + * @neg - sign of the number, %TRUE for negative + * + * In case of success 0 is returned and buf and size are updated with + * the amount of bytes read. + */ +static int proc_put_long(void __user **buf, size_t *size, unsigned long val, + bool neg) +{ + int len; + char tmp[TMPBUFLEN], *p = tmp; + + sprintf(p, "%s%lu", neg ? "-" : "", val); + len = strlen(tmp); + if (len > *size) + len = *size; + if (copy_to_user(*buf, tmp, len)) + return -EFAULT; + *size -= len; + *buf += len; + return 0; +} +#undef TMPBUFLEN + +static int proc_put_char(void __user **buf, size_t *size, char c) +{ + if (*size) { + char __user **buffer = (char __user **)buf; + if (put_user(c, *buffer)) + return -EFAULT; + (*size)--, (*buffer)++; + *buf = *buffer; + } + return 0; +} + +static int do_proc_dointvec_conv(bool *negp, unsigned long *lvalp, int *valp, int write, void *data) { @@ -2050,33 +2164,31 @@ static int do_proc_dointvec_conv(int *negp, unsigned long *lvalp, } else { int val = *valp; if (val < 0) { - *negp = -1; + *negp = true; *lvalp = (unsigned long)-val; } else { - *negp = 0; + *negp = false; *lvalp = (unsigned long)val; } } return 0; } +static const char proc_wspace_sep[] = { ' ', '\t', '\n' }; + static int __do_proc_dointvec(void *tbl_data, struct ctl_table *table, int write, void __user *buffer, size_t *lenp, loff_t *ppos, - int (*conv)(int *negp, unsigned long *lvalp, int *valp, + int (*conv)(bool *negp, unsigned long *lvalp, int *valp, int write, void *data), void *data) { -#define TMPBUFLEN 21 - int *i, vleft, first = 1, neg; - unsigned long lval; - size_t left, len; - - char buf[TMPBUFLEN], *p; - char __user *s = buffer; + int *i, vleft, first = 1, err = 0; + unsigned long page = 0; + size_t left; + char *kbuf; - if (!tbl_data || !table->maxlen || !*lenp || - (*ppos && !write)) { + if (!tbl_data || !table->maxlen || !*lenp || (*ppos && !write)) { *lenp = 0; return 0; } @@ -2088,89 +2200,69 @@ static int __do_proc_dointvec(void *tbl_data, struct ctl_table *table, if (!conv) conv = do_proc_dointvec_conv; + if (write) { + if (left > PAGE_SIZE - 1) + left = PAGE_SIZE - 1; + page = __get_free_page(GFP_TEMPORARY); + kbuf = (char *) page; + if (!kbuf) + return -ENOMEM; + if (copy_from_user(kbuf, buffer, left)) { + err = -EFAULT; + goto free; + } + kbuf[left] = 0; + } + for (; left && vleft--; i++, first=0) { - if (write) { - while (left) { - char c; - if (get_user(c, s)) - return -EFAULT; - if (!isspace(c)) - break; - left--; - s++; - } - if (!left) - break; - neg = 0; - len = left; - if (len > sizeof(buf) - 1) - len = sizeof(buf) - 1; - if (copy_from_user(buf, s, len)) - return -EFAULT; - buf[len] = 0; - p = buf; - if (*p == '-' && left > 1) { - neg = 1; - p++; - } - if (*p < '0' || *p > '9') - break; + unsigned long lval; + bool neg; - lval = simple_strtoul(p, &p, 0); + if (write) { + left -= proc_skip_spaces(&kbuf); - len = p-buf; - if ((len < left) && *p && !isspace(*p)) + err = proc_get_long(&kbuf, &left, &lval, &neg, + proc_wspace_sep, + sizeof(proc_wspace_sep), NULL); + if (err) break; - s += len; - left -= len; - - if (conv(&neg, &lval, i, 1, data)) + if (conv(&neg, &lval, i, 1, data)) { + err = -EINVAL; break; + } } else { - p = buf; + if (conv(&neg, &lval, i, 0, data)) { + err = -EINVAL; + break; + } if (!first) - *p++ = '\t'; - - if (conv(&neg, &lval, i, 0, data)) + err = proc_put_char(&buffer, &left, '\t'); + if (err) + break; + err = proc_put_long(&buffer, &left, lval, neg); + if (err) break; - - sprintf(p, "%s%lu", neg ? "-" : "", lval); - len = strlen(buf); - if (len > left) - len = left; - if(copy_to_user(s, buf, len)) - return -EFAULT; - left -= len; - s += len; } } - if (!write && !first && left) { - if(put_user('\n', s)) - return -EFAULT; - left--, s++; - } + if (!write && !first && left && !err) + err = proc_put_char(&buffer, &left, '\n'); + if (write && !err) + left -= proc_skip_spaces(&kbuf); +free: if (write) { - while (left) { - char c; - if (get_user(c, s++)) - return -EFAULT; - if (!isspace(c)) - break; - left--; - } + free_page(page); + if (first) + return err ? : -EINVAL; } - if (write && first) - return -EINVAL; *lenp -= left; *ppos += *lenp; - return 0; -#undef TMPBUFLEN + return err; } static int do_proc_dointvec(struct ctl_table *table, int write, void __user *buffer, size_t *lenp, loff_t *ppos, - int (*conv)(int *negp, unsigned long *lvalp, int *valp, + int (*conv)(bool *negp, unsigned long *lvalp, int *valp, int write, void *data), void *data) { @@ -2238,8 +2330,8 @@ struct do_proc_dointvec_minmax_conv_param { int *max; }; -static int do_proc_dointvec_minmax_conv(int *negp, unsigned long *lvalp, - int *valp, +static int do_proc_dointvec_minmax_conv(bool *negp, unsigned long *lvalp, + int *valp, int write, void *data) { struct do_proc_dointvec_minmax_conv_param *param = data; @@ -2252,10 +2344,10 @@ static int do_proc_dointvec_minmax_conv(int *negp, unsigned long *lvalp, } else { int val = *valp; if (val < 0) { - *negp = -1; + *negp = true; *lvalp = (unsigned long)-val; } else { - *negp = 0; + *negp = false; *lvalp = (unsigned long)val; } } @@ -2295,102 +2387,78 @@ static int __do_proc_doulongvec_minmax(void *data, struct ctl_table *table, int unsigned long convmul, unsigned long convdiv) { -#define TMPBUFLEN 21 - unsigned long *i, *min, *max, val; - int vleft, first=1, neg; - size_t len, left; - char buf[TMPBUFLEN], *p; - char __user *s = buffer; - - if (!data || !table->maxlen || !*lenp || - (*ppos && !write)) { + unsigned long *i, *min, *max; + int vleft, first = 1, err = 0; + unsigned long page = 0; + size_t left; + char *kbuf; + + if (!data || !table->maxlen || !*lenp || (*ppos && !write)) { *lenp = 0; return 0; } - + i = (unsigned long *) data; min = (unsigned long *) table->extra1; max = (unsigned long *) table->extra2; vleft = table->maxlen / sizeof(unsigned long); left = *lenp; - + + if (write) { + if (left > PAGE_SIZE - 1) + left = PAGE_SIZE - 1; + page = __get_free_page(GFP_TEMPORARY); + kbuf = (char *) page; + if (!kbuf) + return -ENOMEM; + if (copy_from_user(kbuf, buffer, left)) { + err = -EFAULT; + goto free; + } + kbuf[left] = 0; + } + for (; left && vleft--; i++, min++, max++, first=0) { + unsigned long val; + if (write) { - while (left) { - char c; - if (get_user(c, s)) - return -EFAULT; - if (!isspace(c)) - break; - left--; - s++; - } - if (!left) - break; - neg = 0; - len = left; - if (len > TMPBUFLEN-1) - len = TMPBUFLEN-1; - if (copy_from_user(buf, s, len)) - return -EFAULT; - buf[len] = 0; - p = buf; - if (*p == '-' && left > 1) { - neg = 1; - p++; - } - if (*p < '0' || *p > '9') - break; - val = simple_strtoul(p, &p, 0) * convmul / convdiv ; - len = p-buf; - if ((len < left) && *p && !isspace(*p)) + bool neg; + + left -= proc_skip_spaces(&kbuf); + + err = proc_get_long(&kbuf, &left, &val, &neg, + proc_wspace_sep, + sizeof(proc_wspace_sep), NULL); + if (err) break; if (neg) - val = -val; - s += len; - left -= len; - - if(neg) continue; if ((min && val < *min) || (max && val > *max)) continue; *i = val; } else { - p = buf; + val = convdiv * (*i) / convmul; if (!first) - *p++ = '\t'; - sprintf(p, "%lu", convdiv * (*i) / convmul); - len = strlen(buf); - if (len > left) - len = left; - if(copy_to_user(s, buf, len)) - return -EFAULT; - left -= len; - s += len; + err = proc_put_char(&buffer, &left, '\t'); + err = proc_put_long(&buffer, &left, val, false); + if (err) + break; } } - if (!write && !first && left) { - if(put_user('\n', s)) - return -EFAULT; - left--, s++; - } + if (!write && !first && left && !err) + err = proc_put_char(&buffer, &left, '\n'); + if (write && !err) + left -= proc_skip_spaces(&kbuf); +free: if (write) { - while (left) { - char c; - if (get_user(c, s++)) - return -EFAULT; - if (!isspace(c)) - break; - left--; - } + free_page(page); + if (first) + return err ? : -EINVAL; } - if (write && first) - return -EINVAL; *lenp -= left; *ppos += *lenp; - return 0; -#undef TMPBUFLEN + return err; } static int do_proc_doulongvec_minmax(struct ctl_table *table, int write, @@ -2451,7 +2519,7 @@ int proc_doulongvec_ms_jiffies_minmax(struct ctl_table *table, int write, } -static int do_proc_dointvec_jiffies_conv(int *negp, unsigned long *lvalp, +static int do_proc_dointvec_jiffies_conv(bool *negp, unsigned long *lvalp, int *valp, int write, void *data) { @@ -2463,10 +2531,10 @@ static int do_proc_dointvec_jiffies_conv(int *negp, unsigned long *lvalp, int val = *valp; unsigned long lval; if (val < 0) { - *negp = -1; + *negp = true; lval = (unsigned long)-val; } else { - *negp = 0; + *negp = false; lval = (unsigned long)val; } *lvalp = lval / HZ; @@ -2474,7 +2542,7 @@ static int do_proc_dointvec_jiffies_conv(int *negp, unsigned long *lvalp, return 0; } -static int do_proc_dointvec_userhz_jiffies_conv(int *negp, unsigned long *lvalp, +static int do_proc_dointvec_userhz_jiffies_conv(bool *negp, unsigned long *lvalp, int *valp, int write, void *data) { @@ -2486,10 +2554,10 @@ static int do_proc_dointvec_userhz_jiffies_conv(int *negp, unsigned long *lvalp, int val = *valp; unsigned long lval; if (val < 0) { - *negp = -1; + *negp = true; lval = (unsigned long)-val; } else { - *negp = 0; + *negp = false; lval = (unsigned long)val; } *lvalp = jiffies_to_clock_t(lval); @@ -2497,7 +2565,7 @@ static int do_proc_dointvec_userhz_jiffies_conv(int *negp, unsigned long *lvalp, return 0; } -static int do_proc_dointvec_ms_jiffies_conv(int *negp, unsigned long *lvalp, +static int do_proc_dointvec_ms_jiffies_conv(bool *negp, unsigned long *lvalp, int *valp, int write, void *data) { @@ -2507,10 +2575,10 @@ static int do_proc_dointvec_ms_jiffies_conv(int *negp, unsigned long *lvalp, int val = *valp; unsigned long lval; if (val < 0) { - *negp = -1; + *negp = true; lval = (unsigned long)-val; } else { - *negp = 0; + *negp = false; lval = (unsigned long)val; } *lvalp = jiffies_to_msecs(lval); -- cgit v1.2.3 From 9f977fb7ae9ddf565b4800854212fb9a1ed6c2ea Mon Sep 17 00:00:00 2001 From: Octavian Purdila Date: Wed, 5 May 2010 00:26:55 +0000 Subject: sysctl: add proc_do_large_bitmap The new function can be used to read/write large bitmaps via /proc. A comma separated range format is used for compact output and input (e.g. 1,3-4,10-10). Writing into the file will first reset the bitmap then update it based on the given input. Signed-off-by: Octavian Purdila Signed-off-by: WANG Cong Cc: Eric W. Biederman Signed-off-by: David S. Miller --- kernel/sysctl.c | 161 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 161 insertions(+) (limited to 'kernel/sysctl.c') diff --git a/kernel/sysctl.c b/kernel/sysctl.c index 4a976208de29..bcfb79e94ec7 100644 --- a/kernel/sysctl.c +++ b/kernel/sysctl.c @@ -2049,6 +2049,16 @@ static size_t proc_skip_spaces(char **buf) return ret; } +static void proc_skip_char(char **buf, size_t *size, const char v) +{ + while (*size) { + if (**buf != v) + break; + (*size)--; + (*buf)++; + } +} + #define TMPBUFLEN 22 /** * proc_get_long - reads an ASCII formated integer from a user buffer @@ -2675,6 +2685,157 @@ static int proc_do_cad_pid(struct ctl_table *table, int write, return 0; } +/** + * proc_do_large_bitmap - read/write from/to a large bitmap + * @table: the sysctl table + * @write: %TRUE if this is a write to the sysctl file + * @buffer: the user buffer + * @lenp: the size of the user buffer + * @ppos: file position + * + * The bitmap is stored at table->data and the bitmap length (in bits) + * in table->maxlen. + * + * We use a range comma separated format (e.g. 1,3-4,10-10) so that + * large bitmaps may be represented in a compact manner. Writing into + * the file will clear the bitmap then update it with the given input. + * + * Returns 0 on success. + */ +int proc_do_large_bitmap(struct ctl_table *table, int write, + void __user *buffer, size_t *lenp, loff_t *ppos) +{ + int err = 0; + bool first = 1; + size_t left = *lenp; + unsigned long bitmap_len = table->maxlen; + unsigned long *bitmap = (unsigned long *) table->data; + unsigned long *tmp_bitmap = NULL; + char tr_a[] = { '-', ',', '\n' }, tr_b[] = { ',', '\n', 0 }, c; + + if (!bitmap_len || !left || (*ppos && !write)) { + *lenp = 0; + return 0; + } + + if (write) { + unsigned long page = 0; + char *kbuf; + + if (left > PAGE_SIZE - 1) + left = PAGE_SIZE - 1; + + page = __get_free_page(GFP_TEMPORARY); + kbuf = (char *) page; + if (!kbuf) + return -ENOMEM; + if (copy_from_user(kbuf, buffer, left)) { + free_page(page); + return -EFAULT; + } + kbuf[left] = 0; + + tmp_bitmap = kzalloc(BITS_TO_LONGS(bitmap_len) * sizeof(unsigned long), + GFP_KERNEL); + if (!tmp_bitmap) { + free_page(page); + return -ENOMEM; + } + proc_skip_char(&kbuf, &left, '\n'); + while (!err && left) { + unsigned long val_a, val_b; + bool neg; + + err = proc_get_long(&kbuf, &left, &val_a, &neg, tr_a, + sizeof(tr_a), &c); + if (err) + break; + if (val_a >= bitmap_len || neg) { + err = -EINVAL; + break; + } + + val_b = val_a; + if (left) { + kbuf++; + left--; + } + + if (c == '-') { + err = proc_get_long(&kbuf, &left, &val_b, + &neg, tr_b, sizeof(tr_b), + &c); + if (err) + break; + if (val_b >= bitmap_len || neg || + val_a > val_b) { + err = -EINVAL; + break; + } + if (left) { + kbuf++; + left--; + } + } + + while (val_a <= val_b) + set_bit(val_a++, tmp_bitmap); + + first = 0; + proc_skip_char(&kbuf, &left, '\n'); + } + free_page(page); + } else { + unsigned long bit_a, bit_b = 0; + + while (left) { + bit_a = find_next_bit(bitmap, bitmap_len, bit_b); + if (bit_a >= bitmap_len) + break; + bit_b = find_next_zero_bit(bitmap, bitmap_len, + bit_a + 1) - 1; + + if (!first) { + err = proc_put_char(&buffer, &left, ','); + if (err) + break; + } + err = proc_put_long(&buffer, &left, bit_a, false); + if (err) + break; + if (bit_a != bit_b) { + err = proc_put_char(&buffer, &left, '-'); + if (err) + break; + err = proc_put_long(&buffer, &left, bit_b, false); + if (err) + break; + } + + first = 0; bit_b++; + } + if (!err) + err = proc_put_char(&buffer, &left, '\n'); + } + + if (!err) { + if (write) { + if (*ppos) + bitmap_or(bitmap, bitmap, tmp_bitmap, bitmap_len); + else + memcpy(bitmap, tmp_bitmap, + BITS_TO_LONGS(bitmap_len) * sizeof(unsigned long)); + } + kfree(tmp_bitmap); + *lenp -= left; + *ppos += *lenp; + return 0; + } else { + kfree(tmp_bitmap); + return err; + } +} + #else /* CONFIG_PROC_FS */ int proc_dostring(struct ctl_table *table, int write, -- cgit v1.2.3 From ab3c68ee5fd329ba48094d3417fd60e30ea14a87 Mon Sep 17 00:00:00 2001 From: Heiko Carstens Date: Mon, 17 May 2010 10:00:21 +0200 Subject: [S390] debug: enable exception-trace debug facility The exception-trace facility on x86 and other architectures prints traces to dmesg whenever a user space application crashes. s390 has such a feature since ages however it is called userprocess_debug and is enabled differently. This patch makes sure that whenever one of the two procfs files /proc/sys/kernel/userprocess_debug /proc/sys/debug/exception-trace is modified the contents of the second one changes as well. That way we keep backwards compatibilty but also support the same interface like other architectures do. Besides that the output of the traces is improved since it will now also contain the corresponding filename of the vma (when available) where the process caused a fault or trap. Signed-off-by: Heiko Carstens Signed-off-by: Martin Schwidefsky --- kernel/sysctl.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) (limited to 'kernel/sysctl.c') diff --git a/kernel/sysctl.c b/kernel/sysctl.c index 8686b0f5fc12..90f536d84643 100644 --- a/kernel/sysctl.c +++ b/kernel/sysctl.c @@ -621,7 +621,7 @@ static struct ctl_table kern_table[] = { #endif { .procname = "userprocess_debug", - .data = &sysctl_userprocess_debug, + .data = &show_unhandled_signals, .maxlen = sizeof(int), .mode = 0644, .proc_handler = proc_dointvec, @@ -1431,7 +1431,8 @@ static struct ctl_table fs_table[] = { }; static struct ctl_table debug_table[] = { -#if defined(CONFIG_X86) || defined(CONFIG_PPC) || defined(CONFIG_SPARC) +#if defined(CONFIG_X86) || defined(CONFIG_PPC) || defined(CONFIG_SPARC) || \ + defined(CONFIG_S390) { .procname = "exception-trace", .data = &show_unhandled_signals, -- cgit v1.2.3 From b492e95be0ae672922f4734acf3f5d35c30be948 Mon Sep 17 00:00:00 2001 From: Jens Axboe Date: Wed, 19 May 2010 21:03:16 +0200 Subject: pipe: set lower and upper limit on max pages in the pipe page array We need at least two to guarantee proper POSIX behaviour, so never allow a smaller limit than that. Also expose a /proc/sys/fs/pipe-max-pages sysctl file that allows root to define a sane upper limit. Make it default to 16 times the default size, which is 16 pages. Signed-off-by: Jens Axboe --- kernel/sysctl.c | 9 +++++++++ 1 file changed, 9 insertions(+) (limited to 'kernel/sysctl.c') diff --git a/kernel/sysctl.c b/kernel/sysctl.c index 8686b0f5fc12..c649d1c5fe09 100644 --- a/kernel/sysctl.c +++ b/kernel/sysctl.c @@ -52,6 +52,7 @@ #include #include #include +#include #include #include @@ -1423,6 +1424,14 @@ static struct ctl_table fs_table[] = { .child = binfmt_misc_table, }, #endif + { + .procname = "pipe-max-pages", + .data = &pipe_max_pages, + .maxlen = sizeof(int), + .mode = 0644, + .proc_handler = &proc_dointvec_minmax, + .extra1 = &two, + }, /* * NOTE: do not add new entries to this table unless you have read * Documentation/sysctl/ctl_unnumbered.txt -- cgit v1.2.3 From 0fc377bd648d1935ea34665239e3f0a274b71698 Mon Sep 17 00:00:00 2001 From: Randy Dunlap Date: Fri, 21 May 2010 11:29:53 -0700 Subject: sysctl: fix kernel-doc notation and typos Fix kernel-doc warnings, kernel-doc special characters, and typos in recent kernel/sysctl.c additions. Signed-off-by: Randy Dunlap Cc: Amerigo Wang Signed-off-by: Linus Torvalds --- kernel/sysctl.c | 38 +++++++++++++++++++------------------- 1 file changed, 19 insertions(+), 19 deletions(-) (limited to 'kernel/sysctl.c') diff --git a/kernel/sysctl.c b/kernel/sysctl.c index b12583047757..30acc6c87b1b 100644 --- a/kernel/sysctl.c +++ b/kernel/sysctl.c @@ -2083,20 +2083,20 @@ static void proc_skip_char(char **buf, size_t *size, const char v) #define TMPBUFLEN 22 /** - * proc_get_long - reads an ASCII formated integer from a user buffer + * proc_get_long - reads an ASCII formatted integer from a user buffer * - * @buf - a kernel buffer - * @size - size of the kernel buffer - * @val - this is where the number will be stored - * @neg - set to %TRUE if number is negative - * @perm_tr - a vector which contains the allowed trailers - * @perm_tr_len - size of the perm_tr vector - * @tr - pointer to store the trailer character + * @buf: a kernel buffer + * @size: size of the kernel buffer + * @val: this is where the number will be stored + * @neg: set to %TRUE if number is negative + * @perm_tr: a vector which contains the allowed trailers + * @perm_tr_len: size of the perm_tr vector + * @tr: pointer to store the trailer character * - * In case of success 0 is returned and buf and size are updated with - * the amount of bytes read. If tr is non NULL and a trailing - * character exist (size is non zero after returning from this - * function) tr is updated with the trailing character. + * In case of success %0 is returned and @buf and @size are updated with + * the amount of bytes read. If @tr is non-NULL and a trailing + * character exists (size is non-zero after returning from this + * function), @tr is updated with the trailing character. */ static int proc_get_long(char **buf, size_t *size, unsigned long *val, bool *neg, @@ -2147,15 +2147,15 @@ static int proc_get_long(char **buf, size_t *size, } /** - * proc_put_long - coverts an integer to a decimal ASCII formated string + * proc_put_long - converts an integer to a decimal ASCII formatted string * - * @buf - the user buffer - * @size - the size of the user buffer - * @val - the integer to be converted - * @neg - sign of the number, %TRUE for negative + * @buf: the user buffer + * @size: the size of the user buffer + * @val: the integer to be converted + * @neg: sign of the number, %TRUE for negative * - * In case of success 0 is returned and buf and size are updated with - * the amount of bytes read. + * In case of success %0 is returned and @buf and @size are updated with + * the amount of bytes written. */ static int proc_put_long(void __user **buf, size_t *size, unsigned long val, bool neg) -- cgit v1.2.3