| Message ID | 20250325180821.1456154-9-barnabas.pocze@ideasonboard.com |
|---|---|
| State | New |
| Headers | show |
| Series |
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| Related | show |
Hi Barnabás, Thank you for the patch. On Tue, Mar 25, 2025 at 07:08:20PM +0100, Barnabás Pőcze wrote: > Use the `close_range()` system call when available as it is > simpler and faster than iterating `/proc/self/fd/`. > > Signed-off-by: Barnabás Pőcze <barnabas.pocze@ideasonboard.com> > --- > meson.build | 4 ++++ > src/libcamera/process.cpp | 20 ++++++++++++++++++++ > 2 files changed, 24 insertions(+) > > diff --git a/meson.build b/meson.build > index 668ec3969..00291d628 100644 > --- a/meson.build > +++ b/meson.build > @@ -103,6 +103,10 @@ if cc.has_header_symbol('stdlib.h', 'secure_getenv', prefix : '#define _GNU_SOUR > config_h.set('HAVE_SECURE_GETENV', 1) > endif > > +if cc.has_header_symbol('unistd.h', 'close_range', prefix : '#define _GNU_SOURCE') > + config_h.set('HAVE_CLOSE_RANGE', 1) > +endif > + Please move this before HAVE_FILE_SEALS, in alphabetical order. > common_arguments = [ > '-Wmissing-declarations', > '-Wshadow', > diff --git a/src/libcamera/process.cpp b/src/libcamera/process.cpp > index 01503e485..5fa813300 100644 > --- a/src/libcamera/process.cpp > +++ b/src/libcamera/process.cpp > @@ -70,6 +70,26 @@ void closeAllFdsExcept(Span<const int> fds) > > ASSERT(v.empty() || v.front() >= 0); > > +#if HAVE_CLOSE_RANGE > + static const bool hasCloseRange = [] { > + return close_range(~0u, 0, 0) < 0 && errno == EINVAL; > + }(); Why do you need to test this ? Is it because we may be running against a kernel that doesn't provide the system call ? A comment could be useful: /* * The close_range() system call was added in Linux v5.11. Perform a * runtime support check, in case we're running on an older kernel. */ Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> > + > + if (hasCloseRange) { > + unsigned int prev = 0; > + > + for (unsigned int curr : v) { > + ASSERT(prev <= curr); > + if (prev < curr) > + close_range(prev, curr - 1, 0); > + prev = curr + 1; > + } > + > + close_range(prev, ~0u, 0); > + return; > + } > +#endif > + > DIR *dir = opendir("/proc/self/fd"); > if (!dir) > return;
diff --git a/meson.build b/meson.build index 668ec3969..00291d628 100644 --- a/meson.build +++ b/meson.build @@ -103,6 +103,10 @@ if cc.has_header_symbol('stdlib.h', 'secure_getenv', prefix : '#define _GNU_SOUR config_h.set('HAVE_SECURE_GETENV', 1) endif +if cc.has_header_symbol('unistd.h', 'close_range', prefix : '#define _GNU_SOURCE') + config_h.set('HAVE_CLOSE_RANGE', 1) +endif + common_arguments = [ '-Wmissing-declarations', '-Wshadow', diff --git a/src/libcamera/process.cpp b/src/libcamera/process.cpp index 01503e485..5fa813300 100644 --- a/src/libcamera/process.cpp +++ b/src/libcamera/process.cpp @@ -70,6 +70,26 @@ void closeAllFdsExcept(Span<const int> fds) ASSERT(v.empty() || v.front() >= 0); +#if HAVE_CLOSE_RANGE + static const bool hasCloseRange = [] { + return close_range(~0u, 0, 0) < 0 && errno == EINVAL; + }(); + + if (hasCloseRange) { + unsigned int prev = 0; + + for (unsigned int curr : v) { + ASSERT(prev <= curr); + if (prev < curr) + close_range(prev, curr - 1, 0); + prev = curr + 1; + } + + close_range(prev, ~0u, 0); + return; + } +#endif + DIR *dir = opendir("/proc/self/fd"); if (!dir) return;
Use the `close_range()` system call when available as it is simpler and faster than iterating `/proc/self/fd/`. Signed-off-by: Barnabás Pőcze <barnabas.pocze@ideasonboard.com> --- meson.build | 4 ++++ src/libcamera/process.cpp | 20 ++++++++++++++++++++ 2 files changed, 24 insertions(+)