/*
 * perf_hooks.c
 *
 * Copyright (C) 2016 Wang Nan <wangnan0@huawei.com>
 * Copyright (C) 2016 Huawei Inc.
 */

#include <errno.h>
#include <stdlib.h>
#include <setjmp.h>
#include <linux/err.h>
#include "util/util.h"
#include "util/debug.h"
#include "util/perf-hooks.h"

static sigjmp_buf jmpbuf;
static const struct perf_hook_desc *current_perf_hook;

void perf_hooks__invoke(const struct perf_hook_desc *desc)
{
	if (!(desc && desc->p_hook_func && *desc->p_hook_func))
		return;

	if (sigsetjmp(jmpbuf, 1)) {
		pr_warning("Fatal error (SEGFAULT) in perf hook '%s'\n",
			   desc->hook_name);
		*(current_perf_hook->p_hook_func) = NULL;
	} else {
		current_perf_hook = desc;
		(**desc->p_hook_func)(desc->hook_ctx);
	}
	current_perf_hook = NULL;
}

void perf_hooks__recover(void)
{
	if (current_perf_hook)
		siglongjmp(jmpbuf, 1);
}

#define PERF_HOOK(name)					\
perf_hook_func_t __perf_hook_func_##name = NULL;	\
struct perf_hook_desc __perf_hook_desc_##name =		\
	{.hook_name = #name,				\
	 .p_hook_func = &__perf_hook_func_##name,	\
	 .hook_ctx = NULL};
#include "perf-hooks-list.h"
#undef PERF_HOOK

#define PERF_HOOK(name)		\
	&__perf_hook_desc_##name,

static struct perf_hook_desc *perf_hooks[] = {
#include "perf-hooks-list.h"
};
#undef PERF_HOOK

int perf_hooks__set_hook(const char *hook_name,
			 perf_hook_func_t hook_func,
			 void *hook_ctx)
{
	unsigned int i;

	for (i = 0; i < ARRAY_SIZE(perf_hooks); i++) {
		if (strcmp(hook_name, perf_hooks[i]->hook_name) != 0)
			continue;

		if (*(perf_hooks[i]->p_hook_func))
			pr_warning("Overwrite existing hook: %s\n", hook_name);
		*(perf_hooks[i]->p_hook_func) = hook_func;
		perf_hooks[i]->hook_ctx = hook_ctx;
		return 0;
	}
	return -ENOENT;
}

perf_hook_func_t perf_hooks__get_hook(const char *hook_name)
{
	unsigned int i;

	for (i = 0; i < ARRAY_SIZE(perf_hooks); i++) {
		if (strcmp(hook_name, perf_hooks[i]->hook_name) != 0)
			continue;

		return *(perf_hooks[i]->p_hook_func);
	}
	return ERR_PTR(-ENOENT);
}
net-next.git/commit/include/dt-bindings/pinctrl/bcm2835.h?id=c8f325a59cfc718d13a50fbc746ed9b415c25e92'>commit</a><a href='/cgit.cgi/linux/net-next.git/diff/include/dt-bindings/pinctrl/bcm2835.h?id=c8f325a59cfc718d13a50fbc746ed9b415c25e92'>diff</a></td><td class='form'><form class='right' method='get' action='/cgit.cgi/linux/net-next.git/log/include/dt-bindings/pinctrl/bcm2835.h'>
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<div class='path'>path: <a href='/cgit.cgi/linux/net-next.git/commit/?id=c8f325a59cfc718d13a50fbc746ed9b415c25e92'>root</a>/<a href='/cgit.cgi/linux/net-next.git/commit/include?id=c8f325a59cfc718d13a50fbc746ed9b415c25e92'>include</a>/<a href='/cgit.cgi/linux/net-next.git/commit/include/dt-bindings?id=c8f325a59cfc718d13a50fbc746ed9b415c25e92'>dt-bindings</a>/<a href='/cgit.cgi/linux/net-next.git/commit/include/dt-bindings/pinctrl?id=c8f325a59cfc718d13a50fbc746ed9b415c25e92'>pinctrl</a>/<a href='/cgit.cgi/linux/net-next.git/commit/include/dt-bindings/pinctrl/bcm2835.h?id=c8f325a59cfc718d13a50fbc746ed9b415c25e92'>bcm2835.h</a></div><div class='content'><div class='cgit-panel'><b>diff options</b><form method='get'><input type='hidden' name='id' value='c8f325a59cfc718d13a50fbc746ed9b415c25e92'/><table><tr><td colspan='2'/></tr><tr><td class='label'>context:</td><td class='ctrl'><select name='context' onchange='this.form.submit();'><option value='1'>1</option><option value='2'>2</option><option value='3' selected='selected'>3</option><option value='4'>4</option><option value='5'>5</option><option value='6'>6</option><option value='7'>7</option><option value='8'>8</option><option value='9'>9</option><option value='10'>10</option><option value='15'>15</option><option value='20'>20</option><option value='25'>25</option><option value='30'>30</option><option value='35'>35</option><option value='40'>40</option></select></td></tr><tr><td class='label'>space:</td><td class='ctrl'><select name='ignorews' onchange='this.form.submit();'><option value='0' selected='selected'>include</option><option value='1'>ignore</option></select></td></tr><tr><td class='label'>mode:</td><td class='ctrl'><select name='dt' onchange='this.form.submit();'><option value='0' selected='selected'>unified</option><option value='1'>ssdiff</option><option value='2'>stat only</option></select></td></tr><tr><td/><td class='ctrl'><noscript><input type='submit' value='reload'/></noscript></td></tr></table></form></div><table summary='commit info' class='commit-info'>
<tr><th>author</th><td>Ard Biesheuvel &lt;ard.biesheuvel@linaro.org&gt;</td><td class='right'>2017-02-01 17:45:02 +0000</td></tr>
<tr><th>committer</th><td>Ingo Molnar &lt;mingo@kernel.org&gt;</td><td class='right'>2017-02-01 21:17:49 +0100</td></tr>
<tr><th>commit</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/commit/include/dt-bindings/pinctrl/bcm2835.h?id=c8f325a59cfc718d13a50fbc746ed9b415c25e92'>c8f325a59cfc718d13a50fbc746ed9b415c25e92</a> (<a href='/cgit.cgi/linux/net-next.git/patch/include/dt-bindings/pinctrl/bcm2835.h?id=c8f325a59cfc718d13a50fbc746ed9b415c25e92'>patch</a>)</td></tr>
<tr><th>tree</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/tree/?id=c8f325a59cfc718d13a50fbc746ed9b415c25e92'>d53fbdac9d0781e39a13b2ac6b2bd258cf3b4140</a> /<a href='/cgit.cgi/linux/net-next.git/tree/include/dt-bindings/pinctrl/bcm2835.h?id=c8f325a59cfc718d13a50fbc746ed9b415c25e92'>include/dt-bindings/pinctrl/bcm2835.h</a></td></tr>
<tr><th>parent</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/commit/include/dt-bindings/pinctrl/bcm2835.h?id=bf29bddf0417a4783da3b24e8c9e017ac649326f'>bf29bddf0417a4783da3b24e8c9e017ac649326f</a> (<a href='/cgit.cgi/linux/net-next.git/diff/include/dt-bindings/pinctrl/bcm2835.h?id=c8f325a59cfc718d13a50fbc746ed9b415c25e92&amp;id2=bf29bddf0417a4783da3b24e8c9e017ac649326f'>diff</a>)</td></tr></table>
<div class='commit-subject'>efi/fdt: Avoid FDT manipulation after ExitBootServices()</div><div class='commit-msg'>Some AArch64 UEFI implementations disable the MMU in ExitBootServices(),
after which unaligned accesses to RAM are no longer supported.

Commit:

  abfb7b686a3e ("efi/libstub/arm*: Pass latest memory map to the kernel")

fixed an issue in the memory map handling of the stub FDT code, but
inadvertently created an issue with such firmware, by moving some
of the FDT manipulation to after the invocation of ExitBootServices().

Given that the stub's libfdt implementation uses the ordinary, accelerated
string functions, which rely on hardware handling of unaligned accesses,
manipulating the FDT with the MMU off may result in alignment faults.

So fix the situation by moving the update_fdt_memmap() call into the
callback function invoked by efi_exit_boot_services() right before it
calls the ExitBootServices() UEFI service (which is arguably a better
place for it anyway)

Note that disabling the MMU in ExitBootServices() is not compliant with
the UEFI spec, and carries great risk due to the fact that switching from
cached to uncached memory accesses halfway through compiler generated code
(i.e., involving a stack) can never be done in a way that is architecturally
safe.

Fixes: abfb7b686a3e ("efi/libstub/arm*: Pass latest memory map to the kernel")
Signed-off-by: Ard Biesheuvel &lt;ard.biesheuvel@linaro.org&gt;
Tested-by: Riku Voipio &lt;riku.voipio@linaro.org&gt;
Cc: &lt;stable@vger.kernel.org&gt;
Cc: mark.rutland@arm.com
Cc: linux-efi@vger.kernel.org
Cc: matt@codeblueprint.co.uk
Cc: leif.lindholm@linaro.org
Cc: linux-arm-kernel@lists.infradead.org
Link: http://lkml.kernel.org/r/1485971102-23330-2-git-send-email-ard.biesheuvel@linaro.org
Signed-off-by: Ingo Molnar &lt;mingo@kernel.org&gt;
</div><div class='diffstat-header'><a href='/cgit.cgi/linux/net-next.git/diff/?id=c8f325a59cfc718d13a50fbc746ed9b415c25e92'>Diffstat</a> (limited to 'include/dt-bindings/pinctrl/bcm2835.h')</div><table summary='diffstat' class='diffstat'>